The true size of Arapaima gigas

[Acheloos]

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]

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]

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]

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?

[oscar n redtail cat]

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]

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]

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]

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]

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]

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]

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]

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

[Acheloos]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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

[Zoodiver]

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?


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.

[kydsexy]

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]

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]

This one?

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

[kydsexy]

awesome!

[Arowana1]

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]

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]

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]

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]

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]

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]

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]]

Great discussion guys...

[flemming]

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

[Zoodiver]

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

[Austin]

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

[Arowana1]

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]

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]

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]

How about a MeKong cat?

[Acheloos]

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

[Davey_8313]

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]

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]

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]

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]

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]

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?

251286

[Acheloos]

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]

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]

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]

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

[Arowana1]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.

[Ramesh]

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]

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]

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]

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]

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

[Ramesh]

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]

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]

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]

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]

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]

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]

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]

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

[nishant_datta]

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.


Looking forward to the pics !!

[Fishsiam]

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]

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]

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.