The true size of Arapaima gigas [Archive]

Acheloos

08-30-2008, 10:01 AM

Hallo everyone! This is my first post here is about a special topic with which I have dealt since many years. I was always obsessed by the outsized freak animals, especially big fish and big reptiles. You can often read fantastic sizes which are allegedly reported for some species. But after a long research for several species, it turned out, that many of the often-cited sizes are not true in fact. In some cases old big-fish-stories which had never any reputation actually found their ways into scientific literature, because nobody ever doubted it. I have still many older books which quote the size of the great white shark for example with 11 or even 12m. But there was never such a big great white shark, and it turned out later, that the alleged specimen of this size from which it was said that it was caught at the coast of Australia, acutally never existed. There are many similar cases, and some of them are very popular and widely cited as facts, including some fish species which are often discussed in this forum. One of the most extreme cases is the arapaima, which is normally cited to grow up to 4,5m or even 5m (in newer literature you can find more often sizes of 3m as maximum). But have you ever seen an arapaima only close to this size?
I once wrote a longer article about this issue for a site about freshwater fishing in Thailand ( can be seen here: http://www.megafishingthailand.com/content/view/168/53/ ), which I show here again:

How big can Arapaimas grow?

The arapaima is a big fish. Indeed a very big fish, especially for a freshwater-species. But is the arapaima, or pirarucu how it is called in South-America, really the largest freshwater-fish of the world, and how big can it actually grow? In popular and even scientific literature, as well as in the web, you can often read that this species can reach a length of 4,5m and a weight of 200kg. But is this really true? If you look for pictures of the arapaima, you will find a whole lot of photos which show very big fish, some of them well over 2m, but you will never find a picture of one which comes only close to the alleged size. Furthermore, this dates alone are highly dubious, because the relation of weight and length is absolutely unrealistic. It is really strange why never one of the authors and zoologists who wrote about the arapaima became critial at this. As there are many actual recorded specimens with known weights and lengths, it is easy to compare it with the figure of a 4,5m arapaima which would weigh 200kg. One example for comparison would be the record-arapaima which was caught only a short time ago in a fishing-pond in Thailand. It was 2,63m in length and had an enormous weight of 185kg. This are actual dates, and show very well that the arapaima is a very stocky fish. So if a 2,65m long arapaima weighs already 185kg, is it really realistic that one of 4,5m which is nearly two times the length, would weigh only some kilogramms more? No, it is far away from realitiy, because weight increases with the cube and such a fish would have the proportions of an eel and would be only skin and bone. A hypothetical arapaima of 4,5m would weigh at least 970kg, or even more, as many fish show a tendency to become stockier with increasing size. This is really strange, because there are never any mentions of a weight more than 200kg.
The question is now: How big grow arapaimas really?
A zoologist named Karl Heinz Lüling, who reseacherd this question, found out, that the actually largest ever recorded arapaima from South-America was “only” 2,32m in length and weighed 133kg. The length-weight-relations are nearly identical to those of the 2,63m-specimen.. The arapaima has a very wide range, and even keeping in mind that this species is in many regions overfished, so that old and big specimens are becoming scarce there, it would be really strange if there was never an authenticated fish which was actually close to the biological maximum size this species can reach.
During the last decades, several million arapaimas were caught, even in very isolated regions, where there was never something as commercial fishery. This fish is very fast-growing and can reach large sizes in a comparably short time, and it seems that it also dońt live unusually long, so there should be always at least some individuals which managed to reach their full size during their lives.
So from where are the wide-spread dates of 4,5m long arapaimas? They came from a german naturalist named Schomburgk (not to confuse with the famous german zoologist Hans Schomburgk which lived from 1880-1967) who wrote in 1936 about his voyage to Guyana that the arapaima is said to reach a length of 4,5m and a weight of 200kg. He has never seen himself such a fish, and there was also never a recorded specimen of this length, how you can sometimes read. Schomburgk was only told by members of native tribes that the arapaima could grow that big. Thousands of authors used this dates since this time without any critical research. That means that there was never an actually recorded 4,5m long arapaima, and this dates are nothing than hearsay. It is even possible that this was nothing than a translation-error between Schomburgk and the native-tribes, who spoke very probably not the same language as Schomburgk.Given the fact that there is actually a recorded arapaima from Thailand, which weighed 185kg, it is possible that the largest ever living arapaimas in South-America actually reached a weight of roughly 200kg, but even at this weight, they would be only somewhere between 2,70m and 2,80m.
It is interesting that there are some arapaimas from Thailand which are much larger than the actual record specimens from South-America. But those fish came all from fishing-ponds, where they could grow with plenty of food and without any species-specific parasites or diseases which would stunt their growth in their original habitat. Many fish can reach comparably easy record-sizes in man-made ponds withouth strong competition or predators, and especially with alltimes-available food.
As summary you can see that the stories of 4,5m arapaimas are nothing more than tell-tales, but this should not make you forget that this is still a really immense fish-species. But it is neither the longest nor the heaviest freshwater fish of the world. The european catfish or wels Silurus glanis has a similar background of highly tell-taled exagerated sizes, but the actual authenticated record specimen was with a length of 2,78m at least longer than the largert known arapaima, although it was with 144kg not as heavy. The world-record Mekong giant catfish Pangasianodon gigas was at a length of 2,7m nearly of the same length as the world-record arapaima, but with 293kg much heavier. There are also some other freshwater species which can surpass the arapaima in length and/or weight, so the arapaima is not more actually entitled “largest freshwater fish of the world”.

FishingThailand

08-31-2008, 3:38 AM

http://www.siamfishngtours.com/largeimages/tonykafetz86kgarapaima.jpg
Hi,

You make some very interesting and valid points, that are true not just for the Arapaima but for most large freshwater fish species. I noted though that you seem to be implying that the ceiling wieght for the Arapaima is 200kg? And its length 3.MTR?

Thailand's Arapaima seem to be reaching larger sizes than the fish in the wild for obvious reasons. Many of the big ones have come from a background of being kept as pets, and they certainly flourish in Thai ponds and lakes.

However I think that since the obsession with the size Thai Arapaima may grow is a recent phenomenom, we have yet to answer the question of how large they can grow, in any meaningful sense. The biggest Arapaima that I am aware of landed on rod and line in Thailand to date is 224kg, I also have it on good authority that the longest Arapaima in a fishery in Thailand is 12ft, the second longest is 10ft. The length of Arapaima appear to bear little correlation to thier weight, similarly to some other predatory species like the Pike, some are extremely stocky and fat, others are long and thin, it seems to depend largely on feeding habits and availability of food.

As with all animal species nature from time to time invariably throws up a "freak" specimen. When a freak Arapaima is finally captured and verified factually I think we will see peoples opinions on how big they can grow change drastically, I'm betting on 300kg or possibly even a little more.

Acheloos

08-31-2008, 8:26 AM

The largest arapaima about which I could find valid information was this monster with a length of 2,65 m and 185kg which you can see here: http://www.megafishingthailand.com/content/view/158/58/
I don´t doubt that they have the potential to grow even bigger, but there is surely a limit. I would be very interested in your source about the speciemens over 3m. Were they only spied or really caught? Big fish are very often highly overestimated in size if they are still in the water, and very often even on land. And we still have the sad phenomen of exageration.
It is true, the relation between length and weight differs always among different members of a species, but only to a distinct degree. It is for example just impossible, that a 4,5m arapaima would weigh only a little bit more than an authenticated specimen of "only" 2,65m. The weight of specimens with the same length can perhaps differn +/- abourt 50%, but surely not for several hundred percent. And keep in mind that a specimen which shows excessive growth will hardly ever look like it would be starving. A 4,5m arapaima with 200kg would be as impossible as a 4,5m human with only 200kg.
As the breeding of arapaimas in Asia is a comparably recent development, we have surely still not seen the maximum of the size they can reach. But what I wanted to show was mainly that those old dates of 4,5m and 200 kg are not just impossible, but also have no base in actual facts, and that you will never find an arapaima in south america which is over 3m.

Zoodiver

08-31-2008, 4:39 PM

oscar n redtail cat

08-31-2008, 4:42 PM

What 100% freshwater fish is longer than an arapaima?

Only a 2.65m max size in South America? I've seen 4 year old arapaima longer than that.

5m length is not really a stretch. I've seen 4.2m (14 feet) in person a fairly young ages when you think about how long they can live. I would guess 15 feet to be a max size.

Where are our 'facts' coming from? Only Asian fish farms?
:iagree: thats what ive hered they get 2 might own 1 soon :D when the pond is sett up lol :nilly::drool::)

Acheloos

08-31-2008, 4:51 PM

I would really like to know where you have seen an arapaima of 4,2m, or even better see a photo of it. Even if you search for a long time, you can´t find a single photo of an arapaima which exceeds at least 3m. And even at asian fishing ponds specimens like the one with 185kg are true sensations, and very far away from being normal (even if this is not the maximum biological size they can possibly reach). So if 5m are not really a stretch, why are there no photos of arapaima of at least 3m? And keep in mind how huge such a fish would be, it would have a weight of more than 1000kg.
Species like the giant freshwater stingrays and also several species of freshwater sturgeons grow doubtless longer than the arapaima, and its weight is also surpased by species like the giant Mekong catfish.

Zoodiver

08-31-2008, 5:15 PM

No 100% freshwater sturgeon will grow to the size of an arapaima. Only species that get that size go between salt and freshwater. I have yet to see proof of a freshwater ray getting to that claimed size.

Keep looking if you can only find 3m arapaima. Lots of them are out here. My two year old measured a touch over 2 meters and is growing like a weed. In the eight to ten year old range, they are over 9-10 feet and still growing.

I work with captive arapaima in the US doing growth studies, feeding research, transport research and documenting almost anything I can.

Acheloos

09-01-2008, 7:06 AM

The giant arapaimas in Thailand were released in the 90ies, that means they had already a very long time to grow. If they would have really the potential to outgrow 3m with ease, they had reached this size since many years. But even the 185 kg monster was only a bit over 2,5m.
So why are there nowhere photos and actual records of bigger ones? Why aren´t there masses of monsters around 3m. I can not only find photos of arapaimas over 3m but also none with at least 3m? A size of 2m seems to be comparably common, but surely not 3m. Why couldn´t they find during the research a single specimen over 2,32m among many thousands?
And keep in mind that the conditions in aquariums are not the same conditions as those in nature. Many species with a good growth potential can reach sizes much bigger than the average sizes in nature if they are kept in aquariums or ponds (many sturgeons for example which can grow extremely fast with enough food).
And there are extremely large freshwater sturgeon, for example the giant chinese paddlefish Psephurus gladius. Even if the often-cited length of 7m as maximum is extremely doubtfull, they can still grow very large. Just last year a 3,6m long specimen with a weight of 250kg was caught and sadly killed, and there are (or were) bigger ones. And some of the giant freshwater stingrays can reach more than 4m, even if most of their length comes from the tail, but they are still very heavy.

polish

09-01-2008, 11:26 AM

There was just a show called Monster Fish which aired here in the USA, it had a part dedicated to the Arapaima. Many large ones were shown among other facts and information, I have no doubt Zoodiver is correct. Also remember fish never stop growing.

Acheloos

09-01-2008, 1:58 PM

The arapaima is very big indeed, I don´t doubt that they can reach sizes about 2,5 and perhaps even 3m. But this doesn´t mean they can reach every size.
And you are not correct, most fish don´t grow for their whole lifes, this is a widespread myth. Many, especially smaller fish nearly stop their growth after some time, and even in the few species which show visible growth for many years, the growth will slow down more and more.

kydsexy

09-02-2008, 7:17 AM

freshwater stingrays are the largest freshwater fish.

http://news.nationalgeographic.com/news/2008/04/photogalleries/stingray-pictures/index.html

at 4.3 meters, a gigas would easily dwarf this ray and a claim such as "There are accounts of freshwater stingrays growing as large as 1,000 pounds (450 kilograms), which could make them the largest freshwater fish in the world, Hogan said" probably would not be made by any accredited biologist, especially fishing in Asian waters. I have to agree with Acheelos that minus freak species, which none have been verified, A. gigas probably reaches around 3m and 200kg.

Does anyone have any proof that they are capable of growing larger?

kydsexy

09-02-2008, 7:24 AM

i do disagree with Acheelos on at least 1 fact, fish do grow their entire lives, even if it seems untraceable

Acheloos

09-02-2008, 8:07 AM

Some species like many sturgeons or catfish will grow for a long time, but the older they become, the lesser they grow. Very old fish often even loose body weight and have no possibility to invest further energy in length growing.
A lot of fish will reach a distinct size during a distinct time and won´t grow much larger, even after many years. Dependent on their size, they will possibly grow some millimetres or centimetres, but does this really count?
Many people believe that fish and reptiles can grow for their whole lifes and are therefore able to reach nearly every size if the life long enough, but that´s not true. There are very good studies for example about eels from Ireland, which shows that even under optimum conditions and exceptional good growth they have a biological maximum size, even if they will (very slowly) grow untill the end of their lives. This case is especially interesting, because several thousand eels were examined, some of them older than a half century. You can see this study here: http://www.ria.ie/cgi-bin/ria/papers/100439.pdf

kydsexy

09-02-2008, 10:53 PM

not arguing that the growth will dramatically slow down, but growth is growth when you're talking about what's involved considering a fish's life. whether it's a mm of growth or feet of growth, the belief is, and evidence proves that if a fish was to live infinitely, then it would grow infinitely.

Acheloos

09-03-2008, 12:55 PM

No, that´s not true. Please check the article I posted. The growth rate of the eel for example would reach its asymptote when it would be around 200 years old (older than any eel could be), that means there would be no growth any more, and it could not reach bigger sizes, even if it would grow for some more centuries. It´s similar to records in sport. Even the the best runners will once and again break a record for 0,01 or eben 0,1 seconds, they will never come over a distinct limit.

kydsexy

09-03-2008, 5:08 PM

ok maybe "infinite" was exaggeration but no eel will age to 200 years old, which only goes to prove that they grow their entire lives. and runners top speeds differ greatly because it will top off during their lifespan. top speed of an individual as well as group is dependent on many more factors than growth of an animal. i can control the growth of my fish in one year based on amount of food, quality of food, frequency of feedings, optimal water conditions all of which are in our control. genetics play a minor but still somewhat significant role in fish growth. humans are affected by genetics at a much greater rate, which is why Usain Bolt is such a freak of nature!!! If human top speeds followed the same path as fish growth then there would be millions more individuals like Usain running at insanely fast speeds. Just saying, apples to oranges.

also with athletes .01 and .001 and .1 are all drastic differences :)

kydsexy

09-03-2008, 5:08 PM

has anyone read up on the exponential curve of human athletes and that a person of usains caliber wasn't supposed to appear til like 2030!

Acheloos

09-04-2008, 3:05 AM

Okay, sport records were probably not the best example, but I think you know what I mean. As the growth slows down it will come close to a maximum which can´t be beated.
To make a (simplyfied) example lets assume that the growth of a 1m long fish will slow down for 50 percent per year. If it would still grow for 10cm in a year at 1m length it would be 110cm, the next year 115cm, the next year 117,5cm, the next year 118,75cm and so on. In a mathematical sense it will never ever reach 120cm, even if it would grow for millions of years. In nature it would be that it would probably come once to 120cm or even some milimetres more, but it would be never able to reach much larger sizes like 200cm.
I have some very good books with information aoout the growth of animals, for example pikes and wels catfish, but also about big snakes like anacondas. It is true, in such animals the available amount of food and its quality is very important. But genetics are also very important. Even among same conditions some specimens will grow more or lesser than others, even at the same amount of food they consume. This can even cause comparably drastic differences.
To produce a really monstrous specimen you need one with extraordinairy good genetics for growth and optimum conditions too, even for a fish or reptile.

kydsexy

09-04-2008, 6:33 AM

haha i love math :) and a note that if growth slows down 50% a year then it will grow infinitely as the only number you can't take half of is 0. when i mentioned genetics, i simply meant that if 100 3' foot pikes breed, then you can pretty much predict the size of the future offspring, very close to 3' with a few exceptions. on the other hand if 100 humans breed together then size can be predicted but at a very low percentage rate

my dad was 5'3" and mommy was 5'5" im 6'5", my sis is 5'4", and my bro is 6'0" which is why i said that genetics play a more important role in some species more than others--humans compared to fish

Acheloos

09-04-2008, 6:51 AM

The cells of a living body always reproduce themeselves. If they preproduce faster than they die, the tissue and the whole organism will grow (very simplified), if only as much reproduce as die, it won´t grow anymore. I suppose that at one time this will be also the case at very old fish.
Humans´growth is for about 10% dependent from food supply, i.e. people with get only very few and bad food when they grow will in general stay small and people with good food supply will grow in general taller. In animals like (most) fish the supply of food can cause more drastic changes, but even here genetics have a bigger impact than you will perhaps think.
At my guppys I saw also some drastic differences in the growth of the females even among those with the same parents.

kydsexy

09-04-2008, 3:15 PM

i love intelligent discussions!!! it's been a while since i had one :)

im not saying that genetics don't play a role in fish, but it's just not as significant a role as in humans for example. your guppies could have displayed different growth patterns due to amount of food being consumed, overall health from birth, aggression towards one another in the tank setting. the social dynamics of fish are not fully understood, and this can have a drastic effect on the growth of an animal.
Example: salmonid farms & stocking plans
if you visit any salmon/trout farm, you will notice that from the time of hatch, the fish that do not make it to adulthood are the fish that came from unfertilized eggs. during my college years, i visited over 25 salmonid farms and contacted plenty others on their survival rate. over 90% of the hatcheries surveyed boasted a survival rate of 95% or greater and the other were over 80% success rate. there was also a consistent growth rate amongst all of the hatcheries individual growth rates of fish. except for the breeders held from year to year, the size of released fish were with 1/2" of one another.

i think it's cool that you're in Germany. Germany was the first country to successfully raise trout in a fish hatchery. you should call around and ask some of the hatcheries what they feel about lifelong growth rates

Acheloos

09-05-2008, 10:38 AM

Very interesting information. I don´t think there are any trout hatcheries next towhere I live, but it would be surely interesting to visit one. You are doubtless right, in fish the amount of food is much more important for the size than in humans, and with genetics it´s the other way. Just look how immense the differences are between the trouts which live in the small streams which are only some inches deep, and which feed only on small insects and their larvae. It will probably mature at 20cm and never grow much bigger, but if it would live in a big and deep lake, it would possibly reach a length of 1m or more.
But there are still the genetics, even for fish. My guppies lived all among the same conditions, with the same temperature and food. If you look at fish in natural habits, you will also always find some very big specimens, which live among the same conditions as others, but which grew much more.

Aquaman_95

09-05-2008, 10:38 AM

Awsome! I love Monster fish and these fish really are!

Zoodiver

09-05-2008, 8:23 PM

kydsexy

09-05-2008, 10:04 PM

we must always remember tho, even living in the same environment with the same feeding schedule and everything else the same, if i swim at the top and you swim 3 inches lower than me, i might get to eat more food than you because you choose to wait til the food comes to you! but anyways,

thank you for the honestly intelligent discussion! i needed it, im headed back to get my masters and this really motivated me to become a teacher :) even if im teaching the wrong information? lol. be sure to try and find a few German hatcheries, my old aquaculture professor had a ton of pictures from European hatcheries in general, absolutely stunning

Arowana1

09-07-2008, 1:21 AM

I've got a photo of an Arapaima out of one of my books that was published in 1994 and they have a picture ( Jurassic Fishes, on page 4) of a Arapaima caught near Manaus in fishing nets that looks to be about 3 to 3.5 meters. The photo has a fisherman in the frame for some scale (guesstimate 5 to 5'6" tall) and the fish looks double his size. The scales are as large or larger than the man ears. I'm would post a photo however I'm not quite sure how to scan and download photos yet. This fish is longer than any of the fishes posted from the Thai fishing site listed earlier however looks alot leaner.

Zoodiver

09-07-2008, 10:09 AM

This one?

http://www.floridaconservation.org/Fishing/images/fish-pic/arapaima.jpg

kydsexy

09-07-2008, 12:52 PM

awesome!

Arowana1

09-07-2008, 10:04 PM

Yup that's the photo, it seems like it is over 3 meters or 9 feet possibly more. The book has a second photo that is claimed to be of an arapaima that is 9 to 10 foot however their is no scale for the fish in the photo. Zoo diver thanks for posting the photo.

dirtyblacksocks

09-07-2008, 10:11 PM

My thought on Hogan is that he's out to get attention and not qualified to do what he is setting out to do. All large size rumors of these rays are JUST rumors, and nobody has found one larger than an arpaima gigas.

they used to say the same thing about giant/colossal squid :)

frasertheking

09-07-2008, 10:23 PM

This one?

http://www.floridaconservation.org/Fishing/images/fish-pic/arapaima.jpg

looking at that i would put that fish around 8 and a half feet if that is a man of avrage height if you look at the pic the man is hunched over so just my geuss still hell of a fish

Arowana1

09-07-2008, 11:28 PM

If we had an exact idea of scale we could certainly make an worthy estimate. Around three meter (+or-) sounds accurate. If the man is taller than I'm guesstimating the fish is of course bigger. Seems like the man could put his head in the fishes mouth.

Arowana1

09-08-2008, 12:46 AM

The man is also holding the fish forward and up. That makes the fish seem smaller than if it was held strait up and down.

Acheloos

09-10-2008, 1:15 PM

The guy is not standing upright, and the fish hangs not on the ground with the tail. Furthermore the guy is standing behind the fish, what makes it looking even bigger. This fish seems to be actually not longer than about 2,5m, most probably lesser. This is again a good example how big fish can look even bigger than they actually are.
I know that there are only "rumors" about those super colossal freshwater stingrays, but that´s the same with many of the other fish, including the arapaima (and I don´t believe in one of them, especially not in the case of the arapaima and the wels catfish, because I know they are false).
But anyway the giant freshwater rays grow very large. This guy for example could be well in the 3m-range and longer than every arapaima: http://www.gofishing.co.uk/Netstar/StarCommunity/Modules/ImageGallery/Thumbnails/59/30659/3240_11047.jpg

polish

09-10-2008, 1:19 PM

What 100% freshwater fish is longer than an arapaima?

Only a 2.65m max size in South America? I've seen 4 year old arapaima longer than that.

5m length is not really a stretch. I've seen 4.2m (14 feet) in person a fairly young ages when you think about how long they can live. I would guess 15 feet to be a max size.

Where are our 'facts' coming from? Only Asian fish farms?

I am quoting this because I don't get how the original poster can continue with his posts about how they max out at a certain size when a well trusted member of this forum (Who works with these fish) has told you plainly he has seen one over 4 meters.

[enjoyable_attempt]

09-10-2008, 4:27 PM

Great discussion guys...

flemming

09-10-2008, 4:37 PM

what do you think about the european catfish,
here a big guy:
http://www.youtube.com/watch?v=aGCQl2TybPU

Zoodiver

09-10-2008, 6:51 PM

Small enough for one man to pull it into a boat.

Austin

09-10-2008, 6:58 PM

dallas world aquarium has a couple 10-12 footers that i've seen in person multiple times

Arowana1

09-12-2008, 12:45 AM

Sorry that arapaima photo still looks to me like the fish is well over 7.5 ft. or 2.5ft longer than the (even if the man is only 5ft tall) man bent over or not. I still think its in the + or - of 3 meter. I'm actually considering showing this post to my fisheries professor and attempt to calculate some actual numbers on some of these unmarked fish, the man is a fish guru and the resource to make some calculations.

Zoodiver

09-12-2008, 10:04 AM

dallas world aquarium has a couple 10-12 footers that i've seen in person multiple times

The ones they have on display right now were big enough to fit in my hand when we got them in back in '04 (I think it was 2004 anyway). That tells you something right there.

Acheloos

09-12-2008, 2:42 PM

I would be really interested to see photos of this fish. As I said before, there seems to be no photos of Arapaimas in the net bigger than the 2,65m specimen from Thailand. Not from South America, not from Asia or from any zoos. So I find it rather hard to accept specimens in the 4m range if there is not a single actualy proof for one of at least 3m.
And the fish on the photo is by no means 3m.
I made an edited version to show the size-comparison better. The green line shows how tall the man is in this position, the violett line shows how tall it would be if he would stand upright. As it is not directly behind the fish, but bends forward, he would be most probably even taller than this.
The red line is the length of the arapaima. As you can see in direct comparison, the line of the fish is about 1,5m longer than the man´s height. So if this man is not 2m tall, the fish will hardly be in the 3m range. As south american men are in general not very tall, the fish can´t hardly be longer than 2,5m. Keep in mind that the man bends forward and looks even a bit smaller than he is, and the violett line is possibly too short. Furthermore it could be that he is only 1,6m, what would be no uncommon height for a south american man in the jungle. So 2,5m are even possibly too high, and a length of 2,30-2,40m are much more probable.

Davey_8313

09-12-2008, 2:49 PM

How about a MeKong cat?

Acheloos

09-12-2008, 3:02 PM

Well, that´s a completely different species of fish and doesn´t help in any way for this discussion I think.

Davey_8313

09-12-2008, 3:07 PM

The world-record Mekong giant catfish Pangasianodon gigas was at a length of 2,7m nearly of the same length as the world-record arapaima, but with 293kg much heavier.

You brought it up in the first post, just showing people a picture of what you were talking about...:chillpill:

Acheloos

09-12-2008, 3:11 PM

Well, okay. What I wanted to say in the first post (keep in mind that this was mainly a copied article I wrote once for a site about fishing in Thailand and not for the forum posting), is that the arapaima is not the biggest freshwater fish of the world.

Davey_8313

09-12-2008, 3:13 PM

Oh, I know. That's why I was showing a picture of that catfish. They're not longer, but they definitely weigh more. Not trying to derail or anything...

Acheloos

09-12-2008, 3:19 PM

They are possibly even longer, given that I can still not find any authenticated record of more than 2,65 m for an arapaima. And even then, there is still a record length of 2,78m for Silurus glanis and much more for the chinese paddlefish.

polish

09-12-2008, 3:51 PM

I get more and more frustrated every time I open this post. Just a quick Google search easily brought up some Arapaima Gigas which are very large. Exact size aside this is just to show there are many large ones, and none are obviously world records. Just some big catches, so if these are so plentiful what makes you think every one in the world who says 4+ meters is adult size is wrong? Every show I've ever watched or thing I've read states that is adult size, some even say 5 meters. However you, some random person with nothing to back up your claim states they don't reach those lengths. Even after someone has told you they've seen a 4.2 meter Arapaima who as I said before WORKS WITH THEM. I think he knows what he is talking about.

http://www.jakubvagner.cz/_data/1181754766_94.jpg
http://i198.photobucket.com/albums/aa246/bpyun/larry.jpg
http://www.fishingholidaysnet.com/arapaima.jpg
http://bp2.blogger.com/_2F6NQ_-Fucc/SA4jY8iTRdI/AAAAAAAAA3o/me5H3ht23V4/s1600/fishing-paiche.jpg
http://www.fishsiam.com/images/catchReports/2_1214291030.jpg
http://www.jakubvagner.cz/_data/1181754722_69.jpg

Aquariumjunkie

09-12-2008, 3:54 PM

Acheloos

09-12-2008, 4:10 PM

Polish, you should read my first post again (please do it). I wrote there from where the nearly always repeated claim of the 4m+ arapaimas come, from ONE SINGLE SECOND HAND claim from the first half of the 18th century. But this claim, which was probably even based on a translation error, found its way in literature, and that´s the reason why you can find it so often. There are many similar cases, for example the great white shark, for which you can find in many old books a maximum length of 11-12m (again based on a single unauthenticated record).
Furthermore I showed by simple caculations, that the stated dates are in no possible relation, as a hypothetical 4m+ arapaima would be much much heavier than only 200kg.
A weight of 200kg seems not impossible for an arapaima, but not 4m as length. That´s the reason why I named this thread "The TRUE size of arapaima gigas". If you read or hear about 4,5m or even 5m, you will probably think this is a normal length, but this is miles away from being true. Same thing with the wels catfish. A lot of people think they grow usually up to 5m, what´s again just a result of a handfull of very old big-fish-stories which were never proven but found their way in literature.
Today you won´t hardly ever find 11 or 12m as maximum length for the great white shark in a good book, so why is it so hard to accept that there is a very similar situation in Arapaima gigas?

Just look at the photos you posted. They are all very big specimens, but none is just close to at least 3m. The 2,65m specimen is more or less official world record. Don´t you think this is not a bit strange? If this species could easily reach lengths of around 4m, why is the official record so much smaller? Why could an expert which studied thousands of them in their original habitat not find at least one of more than 2,40m?
I have looked for photos of the arapaimas in the Dallas aquarium. They are big by no means, but surely not as big as claimed. A lot of aquariums around the world keep arapaimas, and they often grow to a length of more than 2m. But hardly ever over 2,5m. So why should they grow there so much bigger?

polish

09-12-2008, 4:23 PM

Well written but and I can understand what you mean but there is no proof either way and you can't tell me that last Arapaima (In the photos I posted) isn't every bit of 3 meters. At least I think so. The width of that mans shoulders compared to the fish speaks volumes, as does the fact that the fish isn't even straight and the tail is curled. That thing is a monster.

It's arguing semantics at this point. I just don't see the point but I know the first place I post if I ever see proof. :)

Acheloos

09-12-2008, 4:44 PM

The arapaima has a comparably round body (at least in the first third of the body), so it looks very compact. And take a closer look at the photo. The guy is a good bit behind the fish (just look how big his hand looks compared to his head), which causes a forced perspective, so the fish looks much bigger than it is. If you take his fingers as comparison, you will see that it is actually not that big, and surely not in the 3m range.

kydsexy

09-14-2008, 9:15 PM

oh wow this is still going! i have to read up now!!

Arowana1

09-15-2008, 7:47 PM

Acheloos what would you estimate the Arapaima length to be if I was wrong about the man in the photo and was actually between 5'6" to 6ft tall? As well with some species of fish (especially wild fish) when they are old they tend to become lean and long and girth isn't an appropriate scale to use. I live on a ranch here in California and my family has a fifteen acre pond and I see this once in a while when I catch older largemouth bass. They're long however no where near as robust as young adult fish. I've had old 22 inch bass that weigh as much as a robust young 18.5 inch young adult. Maybe this might be the case with the Arapaima in the photo that its just an old fish.

Acheloos

09-17-2008, 8:02 AM

If you will take a closer look to the photos you will see that the guy on the first photo is the same as the one on the last photo, so it is possibly even the same fish. If you look at the size of the size of the pectoral fin and the size of the head compared to the fingers (4 fingers are together roughly 7-9cm wide), you will see that the head is well within the dimensions of the comparably common arapaimas in the upper range of 2,20m or possibly a bit more.
If you look at record fish, you will often see that many fish become stockier and plumper when they grow larger. A lot of very large record fish are proportionally heavier than average sized fish. When fish grow older, the length growth slows down, and they will convert additional growth not only for length but also for a more robust body. Only if fish are already very old, and no more able to get enough food, they will become slimmer. But at this stage, there was no length growth since a long time. A fish will only grow longer, if it has enough energy resources to support at least its basal metabolism. If this is not the case it will loose weight and there won´t be any length growth anyway.

Arowana1

09-18-2008, 12:24 AM

When looking at these big fish photos, keep in mind that when wild fish grow older and are more worn out providing a meal becomes tougher and they slowly start to become leaner and look long. As well comparing these older wild fish to older captive fish isn't accurate since captive fish don't have to worry about catching a healthy amount of food each day.

Acheloos

09-19-2008, 5:26 AM

But this is only the fact if this fish are already very old. If they are still healthy, they are in general stockier and plumper than smaller fish of the same species (the same can be found in big snakes and crocodiles as well). Record specimens (if you count weight) are not always extremely old. They have to be healthy and well-feed for several (or even many in some species) years, but if they have good genetic conditions and good natural conditions as well (food and temperature) record specimens in general reach a big size within a comparably short time. Some of the species which will live for a long time will in any case need many years to reach record sizes (like sturgeons and some catfish), and during this time they need a lot of food. If you catch an old perch which seems to be slim, then you have to keep in mind that it was once much stockier at this size.
And in general the largest perches (as well as other record fish) are normally very stocky and far away from being slim: http://images.google.de/images?hl=de&q=record%20perch&um=1&ie=UTF-8&sa=N&tab=wi

Acheloos

10-05-2008, 11:28 AM

I made a picture to show the size comparisons between a big arapaima of 2m, the confirmed record specimen from Thailand which was 2,63m and one with the alleged size of 4,5m. As you can see the difference between 2,63 and 4,5m is quite massive, and it would weigh more than a ton. If 2,63 and 185kg is already extemely unusual, why do really so many people believe that 4,5m are possible only because there was this single acount from the first half of the 19th century?

Zoodiver

10-05-2008, 6:02 PM

I'm still not convinced the 2.63 meters (roughly 8 feet) is going to be record size.... mabe in Thailand.
Look around the US and you'll find arapaima that size.

Acheloos

10-06-2008, 3:07 AM

Even if 2,63 is not the absolute record size, I hope you will at least agree that this is undoubtly no normal size. The arapaimas in Thailand had now about 15 years to grow, and in the fishing ponds they had very good conditions for excessive growth.
Perhaps you can manage to grow them even larger in big aquariums, but you have to keep in mind that this 2,63m specimen was already very special among the other ones, which were already unusual big. I have looked on many photos of arapaimas, including such ones from american aquariums, but there was no one which seemed to exceed 3m. Why should everthing be bigger in America?

Zoodiver

10-06-2008, 9:12 PM

I'm not stating things are bigger in the US. I'm just stating that I have personally seen them larger than this. It just happens to be over here. Seeing them a 8 or 9 feet isn't that odd.
I'm not sure why the fish in ponds over there aren't growing the same as the ones I've seen in exhibits over here. It could be a number of factors and I think it's worth looking into.

Just curious, which American aquariums/zoos were used for looking at over all size?

Acheloos

10-07-2008, 2:56 AM

I looked at a lot of aquariums, and actually a lot of arapaimas are even really small. To make an example of some arapaimas which are in a european aquarium in Cologne: They are there since 1972 when they were introduced there with a length of 30-40cm and are still only 1,70m. I know there are a lot of factors which influence the growth of Arapaima, and they are known to reach a weight of 10kg during one year in intensive pond culture. Actually really most of the fish from aquariums, no matter if in Berlin or in Vanquover have Arapaimas which are somewhere in the range of 5-7feet. I also looked at the arapaimas at the aquarium in Dallas, and they are hardly in the 3m range.
How did you see that the arapaimas were as big as you think? Did you measure them? The problem is that big fish are very often highly overestimated in size. I know cases in which big wels in the 2,5m range were thought to be 5m and there are a lot of similar cases. Just look some pages before, even the photo which allowed a comparison made many ones think the arapaima would be much bigger.

Zoodiver

10-08-2008, 6:07 PM

What size anks where these smaller animals being raised in? What are the being fed?
1.7 meters is only a little over five feet for a fish over 30 years old. An arapaima should be over that size in 3 years. Also, when did you see the fish at Dallas World Aq? Several batches have been there, and are inyroduced small (1 meyer or so).

I'm still interested in learning more from your side. I'm just basing growth rate information from what it have seen: here is a pic of a 2 meter 3 year old I had. For size reference, that is a 12" pleco along the left edge and roughly 22" adult motoro stingray on the right side under it's head.

http://www.monsterfishkeepers.com/forums/picture.php?albumid=558&pictureid=4707

Acheloos

10-09-2008, 8:05 AM

I don´t doubt that the arapaima is able to gain sizes of around two metres within a very short time. But this is still no proof that they are able to reach more than 3m. If you look again at the picture comparison I made some pages earlier, you can see how massive the difference between a 2m long arapaima and a 15footer would be. Are there really any arapaimas more then twice the length and more than a ton in weight in Dallas or elsewhere? I highly doubt it.

Zoodiver

10-09-2008, 10:30 PM

I'm just saying that I have seen arapaima longer than the max sizes you are claiming.
So I was wondering where the info was coming from.

Acheloos

10-10-2008, 5:08 AM

Zoodiver, I would have no problem to accept a bigger size than 2,65m, especially for a well-feed specimen from a big aquarium, but only up to a distinct degree. 2,7 for sure, 2,8m probably, 2,9 perhaps still okay, 3m possible. But everthing bigger than this seems very hard to believe if I look at the actual facts.

Ramesh

11-09-2008, 10:16 PM

The ones they have on display right now were big enough to fit in my hand when we got them in back in '04 (I think it was 2004 anyway). That tells you something right there.
Here is a copy of an email I have sent to the 'Dallas World Aquarium' asking them for information about their Arpaima. When I recieve some correspondence I will post it.
If there are any other sources of actual size confirmation please contact these sources and ask for evidence.

"Hello my name is Ramesh Presser and I live in Melbourne Australia. I am doing some research on Arapaima gigas a fish species you have at your aquarium.
I am interested to know the size of your specimens and for how long you have had them?? Also the age of these fish.
These fish are claimed to be the largest fresh water fish species and I am trying to compile credable evidence of the actual size of specimens kept in different facilities around the world.
Any information and help would be greatly appreciated.

Regards

Ramesh Presser"

nishant_datta

11-09-2008, 11:51 PM

Ramesh

11-10-2008, 9:57 PM

If what you say is correct Ache, then Arapaima is not the largest fresh water fish in the world. Wels catfish and Gator Gar have been recorded at much larger sizes. And dude if you don't know (yet) whether something exists or not in the world does not mean it does not. 'Facts' / 'proof' / 'evidence' ?? This isn't a court hearing. But still check out these links:

http://en.wikipedia.org/wiki/Arapaima

http://www.aquaticcommunity.com/predatory/arapaimafish.php

http://www.fishbase.org/Summary/SpeciesSummary.php?id=2076

http://www.aquariacentral.com/fishinfo/fresh/arapaima.shtml

http://www.megafishingthailand.com/content/view/50/53/

http://www.encyclopedia.com/topic/arapaima.aspx

I'm not saying that when a lot of people say something its correct. But hey until you prove the majority wrong, lets just go with them. Also, the one who propounds something should ideally prove the same and expect others to prove him wrong.

I find your reasonong to be highly illogical. If you don't know something exist doesn't mean it does. Evidence and intelligent deduction must then lead to educated assumptions. By your logic anything is possible becuase we don't know. This logical fallacy is called the argument from ignorance, 'Becuase we don't know it must be true"

If there is no clear evidence of something other than anectodal evidence the credence given to such evidence is insufficient to proof it beyond reasonable doubt.
The majority of what people believe to be true has nothing to do with evidence and the facts of a particular matter.
Evidence for a claims must be brought to bear by those who believe something to be true not only by those who dipute it.
The ball is clearly in the "Arapaima 5m largest fish in the world" peoples court to prove their claims and beliefs with credible 1st degree evidence
The earth was once flat and God created the Universe 7000 years ago.
Which many/most people believed/believe dispite no evidence to continue such beliefs and sufficient and clear evidence to support the contrary.
All I want is less claims and more evidence, Picutres, places, people.
I love big fish and would love this to be proofed true but with some credable evidence which support the claims of such fish.

nishant_datta

11-11-2008, 4:25 PM

I find your reasonong to be highly illogical. If you don't know something exist doesn't mean it does. Evidence and intelligent deduction must then lead to educated assumptions. By your logic anything is possible becuase we don't know. This logical fallacy is called the argument from ignorance, 'Becuase we don't know it must be true"

If there is no clear evidence of something other than anectodal evidence the credence given to such evidence is insufficient to proof it beyond reasonable doubt.
The majority of what people believe to be true has nothing to do with evidence and the facts of a particular matter.
Evidence for a claims must be brought to bear by those who believe something to be true not only by those who dipute it.
The ball is clearly in the "Arapaima 5m largest fish in the world" peoples court to prove their claims and beliefs with credible 1st degree evidence
The earth was once flat and God created the Universe 7000 years ago.
Which many/most people believed/believe dispite no evidence to continue such beliefs and sufficient and clear evidence to support the contrary.
All I want is less claims and more evidence, Picutres, places, people.
I love big fish and would love this to be proofed true but with some credable evidence which support the claims of such fish.

Hmm, clearly you don't read between the lines. If read my reply again you'll probably not flame me in the manner you have done. I've said clearly in my post that :

I'm not saying that when a lot of people say something its correct. But hey until you prove the majority wrong, lets just go with them. Also, the one who propounds something should ideally prove the same and expect others to prove him wrong.

Now, in response I'd like to say it doesn't matter what you think is right or wrong or what in your opinion is correct or not. You are certainly not an authority on anything leave alone Arapaima gigas. I am sure you must have done a thorough research in South American river basins yourself but hey I am entitled to my own opinion.

When you participate in a discussion in a forum, try and express (and not impose) your views on others. If there's any credibility in your views they will be appreciated and accepted; otherwise not. I don't know if you have ever worked / researched on the arapaima gigas in their natural environment. If you have, then you are clearly an expert whose views must not be ignored. If you have not and have only been 'researching' on google from your home then you should atleast try raising an arapaima in captivity yourself to make sure that there's ample 'evidence' for you to ascertain this magnificent fish's true size. Then you can clearly ignore the so-called 'experts' or real researchers with practical and real life experience on the subject.

So far as argument of ignorance is concerned it is the most fundamental and universally accepted canon that the one who says / relies on a fact must prove it. When you say that the well established and 'considered to be authorities' web sites / portals are wrong then surely we can except to see some 'evidence' to the contrary which is not forthcoming from you.
Therefore, unless someone says that the arapaima cannot grow beyond 3 metres and proves the same with valid, acceptable and credible evidence, I am willing to believe that the earth is flat. Have a nice day and try not to take things so personally.

BTB0923

11-11-2008, 4:59 PM

I have been truly enjoying reading the intelligent argument being held in this thread, but it is quickly turning into bickering. Please stay on topic and for the sake of the thread argue semantics elsewhere.

Ramesh

11-11-2008, 7:25 PM

Hmm, clearly you don't read between the lines. If read my reply again you'll probably not flame me in the manner you have done. I've said clearly in my post that :

I'm not saying that when a lot of people say something its correct. But hey until you prove the majority wrong, lets just go with them. Also, the one who propounds something should ideally prove the same and expect others to prove him wrong.

Now, in response I'd like to say it doesn't matter what you think is right or wrong or what in your opinion is correct or not. You are certainly not an authority on anything leave alone Arapaima gigas. I am sure you must have done a thorough research in South American river basins yourself but hey I am entitled to my own opinion.

When you participate in a discussion in a forum, try and express (and not impose) your views on others. If there's any credibility in your views they will be appreciated and accepted; otherwise not. I don't know if you have ever worked / researched on the arapaima gigas in their natural environment. If you have, then you are clearly an expert whose views must not be ignored. If you have not and have only been 'researching' on google from your home then you should atleast try raising an arapaima in captivity yourself to make sure that there's ample 'evidence' for you to ascertain this magnificent fish's true size. Then you can clearly ignore the so-called 'experts' or real researchers with practical and real life experience on the subject.

So far as argument of ignorance is concerned it is the most fundamental and universally accepted canon that the one who says / relies on a fact must prove it. When you say that the well established and 'considered to be authorities' web sites / portals are wrong then surely we can except to see some 'evidence' to the contrary which is not forthcoming from you.
Therefore, unless someone says that the arapaima cannot grow beyond 3 metres and proves the same with valid, acceptable and credible evidence, I am willing to believe that the earth is flat. Have a nice day and try not to take things so personally.
No body is flaming you at all mate you shouldn't be so paranoid about a little constructive criticism of your post.
As for reading between the lines you should just write what you are thinking clearly, inferring meaning in such a forum is to difficult.
As for being an expert on Arapaima Gigga's no I am not but I am do have a Bachelor Degree in Science with a major in Zoology and Evolutionary Biology so I am well versed in the protocols of sciencific research and the dictinctions between it and anectodal evidence. As for the experts and researches you speak of who support the belief of 4-5m Arapaima who are they?? What paper/s do they make these claims or assumptions??
I have no doubts of the large size of this great species and you don't need to keep one realise this.
I have doubts about the upper size limit the species is said to be able to reach.
No one has seen a Arapaima reach such a size other the old unverified accounts.
Such accounts are often stated in modern litterature without checking the source or evidence used to support the claims. That is poor science and an example of the propagation of miss leading information. These types of errors in reporting are an all to common occurance in the so called information age where people google something and take it for granted as representing "science" with checking the source of the claims.
I believe Arapaima's can reach 3m maybe bigger why not it's to big a stretch from the upper limits seen today of between 2.5-2.7 but 4-5m is an astonishing claim.
All I question is from which evidence such claims are being based on and if they are verifiable?? Which is what true scientific reseach is about.
Please provide me with the "expets and reseachers" you talk of and I will egarly read the papers they have produced and the evidence they have based their claims on.

catfishlover106

11-11-2008, 7:48 PM

Please Stay On Topic, Leave The Discussion Of Ones Statment Be Brought Through via. Private Message (PM)

Ramesh

11-12-2008, 3:29 AM

The topic is "The true size of Arapaima Gigas" and the discusion is on topic because this discusion is trying to verify this post. I am extemely interested in this type of discusion and certainly bear no one ill will for holding different opinions.
I am an Aussie and I am a very laid back and easy going person and certainly don't take anything personally.
My backgroung and training in science has taught be a critical thinker and to not take things for granted, especially old unverified reccords of fish monster fish.
Acheloos has made many valid points which have been answered with no verifiable evidence of 4-5m fish.
I am waiting for expert evidence, research or pictures that supports the upper size limit many people proport to be true 4-5m.
That's all......there's no need to get excited and upset.
I am patiently waiting...................

Ramesh

11-12-2008, 4:00 AM

I don't know if this has been posted already but it's worth looking at and I have checked out the claims it makes.
It's food for thought, enjoy.
http://www.megafishingthailand.com/content/view/168/53/

nishant_datta

11-12-2008, 7:17 AM

this debate can only be conclusively determined once someone working in the 'field' (natural environment) finds and clicks something as big as are claimed to exist. But 3m + still seems quite possible.

anyway, there are many contenders less spoken of for the crown of largest fresh water including wels catfish (my fav) and chinese paddlefish (clearly the longest if not 'largest'). but these are stated to be close to extinction. mekong giant catfish are weigh a lot.

lets just cheer for our favourite one and hope that someday some angler or researcher will find that record catch.

take care all.

Zoodiver

11-12-2008, 9:56 AM

Here is a copy of an email I have sent to the 'Dallas World Aquarium' asking them for information about their Arpaima. When I recieve some correspondence I will post it.
If there are any other sources of actual size confirmation please contact these sources and ask for evidence.

"Hello my name is Ramesh Presser and I live in Melbourne Australia. I am doing some research on Arapaima gigas a fish species you have at your aquarium.
I am interested to know the size of your specimens and for how long you have had them?? Also the age of these fish.
These fish are claimed to be the largest fresh water fish species and I am trying to compile credable evidence of the actual size of specimens kept in different facilities around the world.
Any information and help would be greatly appreciated.

Regards

Ramesh Presser"

Who did you send it to? If it went the to general info email address, don't expect to get a reply. Zoos and Aquariums get dozens of emails and calls every day of questions like this.

Acheloos

11-12-2008, 12:40 PM

Ramesh, the article you found is actually the one I posted on the first post. I wrote this article for megafishingthailand some time ago.
Nishand_datta: You can actually forgot the wels. We have here a very similar case to those of Arapaima gigas. A small handfull of very old and unconfirmed found their way into literature and were copied without further research again and again. The wels actually grows quite big, but not as big as you can often read. The largest specimens are somewhere between 2,5 and 3m, with the biggest actually confirmed specimen of 2,78m.

Ramesh

11-12-2008, 5:44 PM

Who did you send it to? If it went the to general info email address, don't expect to get a reply. Zoos and Aquariums get dozens of emails and calls every day of questions like this.
I think you may be right Zoodiver but if you know who we can contact to find confirmation of these 4-5m speciems existing it would go a long way to answering the question we are discussing.
I have also contacted a contributor to an anticle written about the sustainability and conservation of the Arapaima in the Amazon basin asking for his opinion and knowledge of such size claims for the Arapaima being true or even possible.
http://journals.cambridge.org/action/displayAbstract;jsessionid=7C4EC9984C290ABA831DA2A F2C7B0EAF.tomcat1?fromPage=online&aid=333489

You have posted a pic of a 2m specimen which is great but not near to the 14ft you have claimed to have worked with. Such a animal must be recorded for scientific purposes as it would represent a significant confirmation of a claim.
Please get to work mate because such things are truely exciting due to their ground breaking nature.

Zoodiver

11-13-2008, 10:28 AM

I searched back through my picture files, and I couldn't find one of that particular animal so far. But I will tell you that I have worked with several above the 3 meter mark for sure. I'll keep looking for pics or a video of the largest ones. I know I have them on an old floppy disc somewhere in a box of old junk.

demjor19

11-13-2008, 11:51 AM

Great thread and info guys! I've really enjoyed the thread thus far!

nishant_datta

11-13-2008, 12:21 PM

Fishsiam

12-03-2008, 9:32 AM

The Fishsiam team has captured Arapaima gigas to 180kg's with the biggest fish measuring 2.6m's.These fish have an incredible girth and are spectacular in apperance.
The Fishsiam team has also caught 50 individual Giant Fresghwater stingray with weights to an estimated 220kg's.This fish was measured at a width of 2.4m's and was a particularily large specimen.We have caught quite a few 2m plus monster stingrays and believe that this species has the potential to achieve the largest weight of any freshwater species.

http://www.fishsiam.com

Arowana1

12-31-2008, 9:41 PM

I agree with Zoodiver that 2.63 meters is probably not going to be record size. In the Amazon basin their is just way to much water (and unexplored water)and food for there not to be an absolute monster lurking. All it would take is optimum condition in a couple locations for these fish (that do grow extremely fast and could live for a long time) to produce some geniun monsters. I've heard of 40 year old clown loaches, and if an Arapiama was that old under optimum conditions it would be a geniun goliath.

Ramesh

01-01-2009, 6:52 AM

No one has officially verified a fish over 3m for this species in the wild or captive and that is a fact.
Zoodiver can change that very easily by showing us a picture or simply tell us which Aquarium keeps such a fish.
If such a fish exists it would be a world record and a first for an officially scientifically verified Arapaima.
I have heard all the big fish stories before and yes big fish do look really big in real life and under water even larger.
If there are serval where are they and bring a measuring tape.
Lets make some history.

FishingThailand

04-24-2009, 3:12 AM

Hi,

Here in Thailand I can tell you a few facts:-

1. We (Saim Fishing Tours) held(or still hold although a submission is now in for a bigger fish) the world record for the Arapaima for a few months at 86kgs the fish measured 72 inches (these figures are approx becuase I dont have paperwork to hand as I am typing this.
http://www.thailandfishingandgolfholidays.com/index.php?showimage=509

2. We have captured Arapaima more than twice the size of the one we submitted as a record, and I would say it was around 50% longer
http://www.thailandfishingandgolfholidays.com/index.php?showimage=421

3.We also have unsubstantiated claims, yet from credible people here in Thailand of fish to 12ft long, and fish weighing 224kg from different sources. I am conifident of the 224kg but not confident of the claim of 12ft.

4. There are those that believe that Bungsamran fishing park in Bangkok holds several specimens that could be in the 250kg to 300kg range. I dont think these fish would go longer than 9ft/10ft though.

Personally I think one of the problems is that too many people over estimate weights in the first place. If you compare the 2.63 Mtr fish at an estimated wieght of 185kg and then compare the one we captured in January this year which we know for a fact was at least 17yrs old and we put an absolute ceiling on it of 9ft and 200kgs (more likely 185kgs) we dont see any comparison with the much younger fish of 2.63mtrs that others here are claiming is "verifiable". Its certainly know more verifable than those we have captured. What gives our clients fish away as a bigger specimen is the girth and depth, but also the tell tale signs of a fully mature fish which can be seen in the scale colouration, the red flash on the scales reaching to within 5 scales of the top of the specimens head.

5. If people do not weight and measure fish accurately we will will never answer these questions which is perhaps why this thread runs on and on, its difficult to weigh and measure a large fish accurately and release the specimen safely, which is why so many fish out of Thailand have estimated weights placed on them. They come from catch and release fishing venues and most anglers want to return them alive. I stand by the suggestion that sooner or later Thailand will throw up a freak and its going to be 9ft/10ft long and in the 250kg to 300kg range. Far bigger than any Arapaima from the wild, but still not the biggest freshwater fish, not by a mile.

Acheloos

04-24-2009, 12:59 PM

Sorry, but I really can´t believe in your claims. At first a 72 inches long arapaima would be surely no world-record (or was this a typo?). And in most cases of unsubstantial claims about outsized animals it turns out that they were exagerations. And why are there never photos of such animals? If the arapaimas in the fishing-ponds of Thailand would grow to 4m, why don´t we have masses of photos showing at least 3m specimens?
It is surely not easy to measure and weigh such a big fish when it is still alive, but it should be possible to make a photo, even one which does not use forced perspective to make the fish looking bigger.

Ramesh

04-25-2009, 6:05 PM

Quote "1. We (Saim Fishing Tours) held(or still hold although a submission is now in for a bigger fish) the world record for the Arapaima for a few months at 86kgs the fish measured 72 inches (these figures are approx becuase I dont have paperwork to hand as I am typing this."

I am sure bigger fish have been taken and verified in Thailand and have in been kept in large aquaria.
Your record must be for a particular class of fishing equipment used to land a fish spp I think.
As for a fish 50% longer that would be a 9ft specimen which is what I have seen mentioned as the largest fish captured in Thailand.
I believe there could be larger fish but substantial evidence never seems to be forth coming in the vast majority of big Arapaima stories.

FishingThailand

04-26-2009, 1:02 AM

FishingThailand

04-26-2009, 1:13 AM

Just to add a point Spotted Gar. I dont who/what you are referring to when you suggest that there are manipulated pictures around. the links to the two pictures I posted are distorted or at least I should hope not! They where taken with a $3000 camera! To give you some perpestive for the fish in the second photo which is of a fish in the 185kg to 200kg Bracket, the combined weight of the 3 men holding the fish is 51 stone or around 714lb. Does this help?

I agree that its unlikely any Arapaima will go 4mtrs, and 3 is a push, even for a 400lb fish, that was really the point I was trying to make.

mkman

04-26-2009, 1:33 AM

I trust zoodiver and what he says BUT I would like to see pics. Also were these estimates or did you measure them? Sometimes fish look bigger than they really are but I would trust Zoodiver.

FishingThailand

04-26-2009, 2:26 AM

"Also were these estimates or did you measure them?"

Ahh an intelligent question at last, and really the whole point that I am trying to make. The IGFA require measurements, length and girth, and photographic evidence to substantiate claims. An independant witness is also required, that is why most big fish captures dont qualify, there is missing evidence.

So in answer to your question. The world record of 86kg is wieghed and measured, at 86kg, 72inches long, 42 inches wide and has been independantly verified. So 72" is 1.83mtrs. So can 80cms add a 100kgs of weight to a fish? Perhaps someone more qualified than me can answer that question. I would guess the big Arapaima we captured in January was at least 50% longer again, and had a 60inch+ girth, so once again this suggests a length of at least 107inches or 2.71mtrs.

So a pattern seems to be immerging doesnt it? The average size of a fully grown Arapaima seems to be around 2.6 to 2.8mtrs,as others here have implied.

However my suggestion for everyone speculating on the ceiling length and wieght consider the simple fact that so many fish that have have been far more of a target for sport than Arapaima have (until recent years) had records standing for many years but then have been broken repeatedly, until in the end limits start to get set. I dont think we are anywhere near it with the Arapaima yet. The next record will take the verified wieght and length for the Arapaima to around 2.7 to 2.8mtrs and 185kgs as a number of fish this size have been taken recently and as far as us here in Thailand are concerned that is FACT.

The fish that follows will be in the definition of "freak" becuase it will push just beyond 3mtrs and weigh around 230kg to 250kg, and will be one of these "unsubstantiated fish" that become part of myth or gossip in all circles of people taking an interest, just like what is happening on this thread!

This is nothing more than a prediction, but it is a prediction that is based in fact, as this has happened with so many of the worlds sporting fish species. My prediction is the freak fish will come out of Thailand, either from Gillhams Fishing Resort or Bungsamran. Both venues alreay have numerous specimens hitting the adult average size of 160kg to 185kg, all we need is a little genetics or diet to come into play and then a typically 2.6 to 2.8mtrs is going to stretch to a legendary size. (The owner of one of the venues repeatly tells me he has ONE OR TWO FISH out of some 50 adults beyond 10ft now! So there ya go...a really big Arapaima is going to be about 3mtr

Acheloos

04-26-2009, 3:53 AM

The average size of adult arapaimas is surely not 2,6-2,8m. If this would be the case, there would be masses of such fishes, which is not the case. The ichthyologist Karl-Heinz Lüling who examined the arapaima in its south-american habitat could not find a single one over 2,40m.
You should also not forget, that the arapaimas in the fishing-ponds in Thailand probably grow better than in the rainforest-rivers.
BTW, even if the official world-record arapaima was caught in Thailand, there are many really documented specimens which were much larger. The reason why I doubtet your statement was just very very low size of this specimen, and I could hardly believe that this is already record. A much larger one was caught in Brazl by the famous Czech angler Jacub Vagner. You can see some photos of the 2,49m and 130kg specimen, including a photo of the scale with which it was weighed:
http://www.jakubvagner.cz/en/5-world-record
This is a very interesting case because we have here respectable photos and dates about length and weight. So we can use them also to get a vague idea about length-weight-relations of bigger fish. Using this proportions, a 3m arapima would weigh around 225kg.

Ramesh

04-26-2009, 7:33 AM

LOL,

I really do have to laugh at you lot! The statments I make are FACTS, not speculation. YES our client holds the world record for the Arapaima, (although a claim for a 130kg specimen is now pending I believe, or may have been accepted,but non the less this is still a small fish) its the All Tackle Class Record , the fish was 86kgs and 72 inches long and 42 inches at its widest. The previous record was 83kg out of Ecuador and it stood as a record for some 13 years.

Heres the International Game Fishing Association Certificate.

http://www.siamfishingtours.com/igfasml.jpg

I didnt come to the forum to claim bragging rights! The purpose was to try and help you lot decypher the bull from the truth, take it from people who know becuase they handle the species regulary. Now reread my previous post in this context.

I am laughing too because you think your piece of paper means you have caught the largest Arapaima :ROFL:.
http://www.megafishingthailand.com/content/view/158/58/

Bigger fish have been caught and indeed exist and that is also a fact.
The question we're trying to establish is the upper size limit of the fish, which from all available evidence is an over exaggeration that has never be verified.

FishingThailand

04-26-2009, 10:09 PM

Ramesh, Im laughing too! At your inability to read!:ROFL:

Of course I didnt post the world record to imply we caught the biggest fish, quite the opposite,the point I was illustrating is that at present the IGFA is the only mechanism by which the general public can believe claims that are published.(although even that is debatable it seems!)

In the angling industry everyone understands the difference between official records and simply unverified claims. We have caught at least 3 Arapaima twice the size of the current world record in the last year, and dozens of fish over a 100kg, the problem is its dangerous for the fish to wiegh them.

Also I am not sure why you cite the link your citing, this is a "news" site, so is third or fourth hand informationand that particular link is very old news! The news is created by those catching the fish or those that own them.

The biggest Arapaima captured anywhere in the world is certainly not any of the ones you are using as frames of reference and that was the whole point I was trying to make.

86kgs is nothing, 130kgs is nothing, 180kg+ 2.6MTR plus Arapaima are common here in Thailand and I know of at least 4 fisheries that hold them right now, and two fisheries that are likely to hold slightly bigger fish.

Acheloos, you make the point about Karl Hienz, but you miss the point! The biggest Arapaima do not reside in the wild, again this is common knowledge in our industry and probably in the commercial aquarium trade to. The average size of FULLY grown adults here in Thailand is generallly accepted as being larger than their Latin American bretheran.

If you don't believe poor little ol' me why dont you send an Email to Gillhams Fishing Resorts? The owner Stuart has handled more Arapaima than anyone in the world, and has spent many $100,000s of dollars buying up Thailand's biggest Arapaima from private owners, and fish farmers who hold breeding pairs. Stuart is considered the authority in the industry, and if you communicate with him or watch what is captured at his fishery in any given month then maybe you guys will learn something about this fish. But based on the intellect of some of the comments posted here, dont expect him to allow you to do free research for your doctorates!:ROFL:

FishingThailand

04-26-2009, 11:01 PM

PS: I should add, anyone who goes into the wild to target an endangered species and is then instrumental in that specimens death, is not the definition of an angler in my books. To then use a dead fish for publicity or claim a record is even worse!

Ramesh

04-27-2009, 4:12 AM

The point is you are tell us all nothing new.
I found that "old news" with a single google search proving that your current IGFA records means squat in the real world.
All news has to come from a source, that is what reporting the news is all about.
The only important question is the accuracy of what is being reported not if it is first or second hand evidence.
Are you questioning the accuracy of the story and the size of the fish??
Otherwise there is nothing wrong with the source or the story.
All the "old news story" shows is that your 2008 records is irrelevent.
Is IGFA debatable?.....IGFA is 100% debatable, as it is clearly not indicative of the fish people in the industry are able to catch regularly.
As for it being the "only" mechanism for the public to judge facts from fiction as you falsely claim, it is not.
People can google many of the Thai fishing sites or visit one of the large public aquaria in the States to see first hand evidence.
The fact the IGFA doesn't know that it's record isn't worth the paper it's written on shows that the "evidence" you rely on as the official (first hand) and verified (IGFA) as "fact"(86.28kg) are wrong.

I am sure we are on the same page with Arapaima being a huge fish who's adult size is often over estimated and shouldn't be harmed just to claim an official new record size.
Yes you are 100% right like Achloos that Thailand will and probably does hold the largest possible fish some where in one of it's lakes.

Acheloos

05-01-2009, 3:46 AM

FishingThailand, if you had read my posts properly, you had seen that I don´t doubt that the biggest arapaimas will most probably don´t come from south america, but from Thailand or anywhere else in Asia, I mentioned this already before you joined this thread.
But anyway, it is still important to document those giants. There is allways a lot of hearsay and tell-tales in angling, and in many cases, there are a lot of exagerations. Today nearly everybody owns a camera, and it is no problem to make photos, and I don´t mean photos with forced perspective, but photos which show a clear size relation at best with a tape. The issue of weight is a problem, and of course it is not easy to weigh such a big fish, especially when you practice catch-and-release. But there is still a lot on inaccuracy about estimated weights, and I suppose they are often overestimated.

FishingThailand

05-03-2009, 6:47 AM

OK, now we seem to be starting to get somewhere. I am telling you something new Ramesh, becuase you are looking at images of fish claimed to be 185kg, and implying its accurate. I am telling you it is not, and the reason i know is becuase I know for fact we have captured bigger fish and I would struggle to claim them to be 185kg.

My whole point from the start is that people are over estimating the size of their catches. I certainly consider the IGFA as an official record keeping body as "lacking credibility" for reasons I cannot state publicy for fear of a law suit! The Arapaima record is the only record we have assisted clients claiming becuase it was an experiment for us in testing the integrity of the IGFA, and it was an interesting exercise!

All I know is that some of the fish you guys are citing as credible or verfiable examples are highly likely to be considerably lighter than the quoted weights claimed for them. I also know for a fact that several fish our guests have captured in the last year illustrate that point quite eloquantly! If we catch a fish that we consider to be say 160kg....but its clearly much larger than one others with supposed credibility are claiming is 185kg. What are we to do? You see this was the whole point I am trying to make. One of you guys talks about a 185kg fish of 2.63mtrs as being fully reported and "factual". I can tell you if that fish wieghed 185kg then others caught elsewhere in Thailand weighed well over 200kg!!! But that is not what I believe. What I believe is that if you reduce the estimated weight by around 20% to 25% your gettng closer to the mark, so a mature 2.63mtr fish is maybe more like 150kg/160kg. a 2.7+ fish might typically be 185kg which i think is getting to the size limit for anything other than a couple of overfed or genetic freaks, and sooner or later someone is going to catch one of those and will be wieghed and measure properly. The arapaima will never be the worlds largest freshwater fish with a ceiling weight of perhaps less than 500lb.

arapaimag

05-07-2009, 8:09 PM

Acheloos thank you for your thread and such informative and articulate posts.

Ramesh and Fishing Thailand I enjoyed and thank you for your knowledgeable contributions.

I too feel that in time the large fishing/breeding pond/lakes might get the future monster Pima recordholders of 3m or more. That could be in Thailand, Malaysia, other Asian countries or in the Americas like Brazil, Peru, Belize etc.

Your thread has been a myth buster and reminds me of the last line in this passage from Lucretius, my favourite philosophical poet

Look at a man in the midst of doubt and danger,
and you will learn in his hour of adversity what he really is.
It is then that true utterances are wrung from the recesses of his breast.
The mask is torn off, the reality remains

Acheloos

05-10-2009, 9:51 AM

I just bought a short time ago a book about osteoglossiformes by Karl-Heinz Lüling (I mentioned him already in the very first post of this thread), who examined the arapaima in its natural habitat. He wrote that in most regions the average size was nearly exactly 2m, sometimes a little bit more. He also wrote that the old hearsay-claims of 4,5m is highly unprobable, and believed that the maximum lengths are about 3m. In regions with strong fishery, specimens of 1,5m were already rare.

arapaimag

05-10-2009, 3:16 PM

I believe that Dr. Karl-Heinz Lüling of the Zoologischen Forschungsinstitut und Museum A. Konig in Bonn Germany is still considered the greatest authority of Arapaima gigas to have ever lived in the world for his 12 month study on them in Peru.

The famous fish enthusiast and National Geographic funded ethnologist Harald Schultz of the Museu Paulistra Sao Paulo, Brazil described him as such in articles on A.gigas Schultz wrote in the 1958 to 1961 period.

In late 1958 Schultz who spent many years in the Amazon traveled up the Japura river to meet the Maku indians (of the blow gun and poison dart fame). He describes the many ways the natives were already reducing and endangering the population of the A.gigas. From the commonly seen 2 person boat and harpooning. To the sometime up to one month kill in an area of every living of adult A.gigas using the “Fisga” method, the illegal and deadly “curral” method and the 30 foot ground net method.

Schulz describes a typical days catch in curral that he witnessed as being: “Three were small about 3 foot long and there were four giants 5 to 6 feet long.”

This shows that a man who spent many years of his life studying in the Amazon considered 5 to 6 foot A.gigas to be giants even in 1958.

The earliest realization of the depletion of A.gigas and subsequent captive breeding of them to replenish stock was by Dr. Carlos Estevao the late Director of the Museu Paraense Emilio Goeldi in Belem do Para in the first half of the 20th century. He actually did the captive breeding in ponds on the university grounds and also introduced about 10,000 of the fry to northeastern Brazil where they had become native by 1961, according to Schultz.

Acheloos

05-10-2009, 3:24 PM

There is also photo in the book which shows a very big specimen caught by fishermen, somewhere in the 2,5m region (but it is hard to estimate the correct length, as the people there are often comparably small). There are also some very interesting dates of specimens from zoos with dates of length and weight, and they were really measured and not just estimated.
I own also a very good book written by Lüling about lungfishes.

Ramesh

05-11-2009, 8:22 AM

Arapaimag, I agree I have really enjoyed this thread and thank Acheloos for starting it.
I studied science at Uni and have a degree in evolutionary biology and stongly agree that impirical evidence is always the gold standard in field biology.
Observations coupled with pictures and accurately collected measurements and data are always better the anecdotes and memory.
In the case of this truely great species the anecdotes and the hard data simply don't match up.
The largest animals would be expected to be found in the closed systems of the large Asian lakes and while some very large fish pushing 2.7m+ have been caught none have come anywhere near the sizes often mentioned for this species.
I agree with yourself and Acheloos that 3m would be towards the upper limit for this species with fish of 2.7 plus beening very rare and special.

gigas12

05-11-2009, 12:18 PM

Hi,yes I agree,with the destruction of their natural habitat and great pressure caused by over fishing,today it would be really hard to see a.gigas that measure 3meters or more.

Acheloos

05-13-2009, 11:59 AM

You have to keep in mind that lengths in the 2,5m region were already extraordinairy in regions without commercial fishing, and there are still such regions, which can hold record-animals like the one Janus Vagner caught.

polish

05-13-2009, 3:05 PM

Well I am still not convinced they can't reach at least 4 meters but I do have this to add.

I just spent the entire morning looking through 110 pages of Google image search results. 55 pages for the word Pirarucu and 55 pages for the word Arapaima Gigas, I couldn't find any images of one that is larger then whats already posted in this thread and others. That doesn't mean they don't exist but I really wanted to find proof. I did find one small 100x100 pixel image of one that looked to be at least 10ft (3m+) but it couldn't be enlarged and when opening the page the image isn't there. It only showed up in the image results as a tiny thumbnail. However being that small of an image I didn't bother saving it because there would be to much speculation as with all the photos already posted. I was hoping to find one with a measurement but couldn't.

I'll continue my search but it's not looking good for me. Especially after watching the different shows on Discovery channel featuring Jeremey Wade and Zeb Hogan where both had a difficult enough time just catching one, let alone a monster. They may have been fished out so much that there are so few monsters left they'll never be seen. I also noticed on a few of the Amazon fishing sites they only list max size at 3m or 9ft. Perhaps this is just because it's the largest they've ever caught or they beleive that is as large as they get desite many other sources claiming 15ft is possible.

The debate continues...

Ramesh

05-13-2009, 8:24 PM

It's basically called an over estimation or exaggeration and is a very common artefact of early feild biology and often occurs in species that are awe inspiring and have the ability to capture peoples imaginations.

Many animals such as Tigers, Lions, Elephants, Great White sharks, large constrictor snakes, whales, large Cephalopods and Crocodilians all have accounts of extremely large animals being recorded in literature.
Many are simply errors in observation/measurement or simply the former explaination.

chrisdef15

05-30-2009, 10:40 PM

I cant believe this stupid argument as gone on as long as it has. Ofcourse there could be or has been bigger Giga's out there.

As has been said fish basically grow there whole lives. I dont care about the semantics of they slow down ect. Big deal, fact is they keep growing.

Alot of these "giant fish" caught in Asia have only been there (according to the guys in this thread who claim to work there) less then 20 years. That could be only half of there lifetime meaning they have plenty of growing to go. From what ive seen alot (not all) of these fishing parks and ponds are WAY more heavily stocked then nature, probably not exactly providing ideal growing conditions even if they are fed pellets ect to beef them up.

And overfishing (and pollution, habitat dectruction ect) would have wiped out alot of the big guys from the wild. Its highly likely there where massive 4-5 meter Giga's in the wild 100 years ago when the claims where originally made, same with catfish species, sturgeons, and even croc's ect but since it takes 50 years plus pristine conditions to get that size it doesnt happen much anymore these days as they get caught or killed before getting to that size.

Acheloos

05-31-2009, 11:09 AM

Why don´t you care about the growth-curves? This is essential to understand the maximum sizes of animal. Even if an animal growns nearly its entire life, this doen´s matter if the growth at older ages is only minimal. Arapaimas are known to reach very big sizes within a very short time, but of course this initial massive growth doesn´t stay for their whole lifes. There are many examples of animals like fish, amphibians and reptiles, which lived very long, and where the growth was dated over many years or even decades. It is for example known that some very large crocodiles in captivity reached sometimes huge sizes in about 20 years or so, but even decades later there was not a single metre more. If the additional growth per year is only some centimetres, it doesn´t matter when an animal grows for its whole life. Furthermore every futher centimetre needs more energy to grow, because animals don´t only grow in length, but in three dimensions. To double the length you have to increase the weight for 700 % at least.
And the fishing ponds in Asia or elsewhere may have a denser population of fish, but still they have often much more food, especially compared to the comparably poor rainforest-rivers of South America.
And what you still don´t understand is that this stupid stories of 4-5m arapaimas comes only from one single second hand report. There were never anywhere reports of arapaimas of this size. You also don´t see the fact that there is still a lot of room without any fishing and pollution, and where arapaimas can life and grow without being stressed. In regions without fishery the adult size is on average about 2m. Arapaimas are not like sturgeons which are nearly everywhere highly overfished, but only regionally, so there are still a lot of them which can reach their maximum sizes in the wild. But still from this regions we have NO specimens reaching only 3m. I don´t understand why you are so ignorant towards this arguments and facts.