We put away 1.5' mullet yesterday - 4 apurensis

[thebiggerthebetter]

The heart break rolls on.

Two more have gone in a similar way to the first apurensis that died, not entirely - no floating and not as long - but other than that all the same. All of the remaining three have been actually sick but two have already passed on and one is still hanging on by a thread.

What happened was they were feeding quite well, as usual, a couple of months ago (they did take a break for a month or two a year ago or so, which worried me, but then returned to their normal greedy selves). They were already taking ~14"-16" mullet whole readily and eagerly and their two last meals were these size mullet, whole and cut in 3-4 pieces. I caught the mullet myself locally. It's been properly frozen for about 6 months.

The mullet wasn't the only feed I have been giving them throughout our time together but various kinds of frozen marine fish and occasionally pellets, which they didn't particularly go after but swallowed some.

Anyhow, they digested the second to the last meal ok 1-1.5 weeks before their last meal but the last one they regurgitated half digested in one day and have been regurgitating mullet backbone vertebra, one or a few at a time, for several days.

Never ate after that growing weaker and now in about two months two have passed on. Epsom salt baths didn't have an effect.

At first I thought that maybe they couldn't digest the thick mullet vertebra, kind of like pelicans can't digest bones of larger fish and die slow and agonizing death but then I remembered that 1 and 2 years ago I would occasionally offer and they would feed on same size mullet and other 1'-1.5' frozen fish (but cut up in rough large pieces as they were smaller). In fact the title of this thread confirms that.

So my second thought is that the diet of 99% frozen marine fish could be what was killing them. Perhaps thiaminase. I should have soaked the feed in Vitachem or stuffed pellets in the feed.

But I thought that malnutrition would not kill that fast and that sudden and would give more time and more symptoms to react to... Wrong????

I don't have any other clues except some wild guesses that maybe just before I caught them the mullets fed on something that's toxic or impassable by the apurensis. But such guesses are fruitless.

Anyone? Kirk Yellowcat ? V victor448 - sorry Jeff. The one you just gave me is doing well, no worries. I hope to learn from these deaths, so this guy doesn't meet the same fate. You said you fed it massivore. Now I think it is very wise of you.

The biggest one reached ~22" in the 3 years with us starting from 5", so their growth rate can be not too shabby. Its head and pretty much the mouth too were 6" across. I bought it first of all 4 from George Fear and his Shark Aquarium in Aug 2015 and it came already with one eye. Didn't stop it from growing the boss:

 

[Matteus]

I’m sorry for your loss Sir.

I just came from my lfs from a meeting with a local legend about my bristlenose pleco dying from bloat after nothing working. He says that despite anything we do some fish just aren’t going to make it to their full life span. He likened it to us humans, not everyone is going to make to our 90’s even if we have good diets and excercise.


With all that being said, it doesn’t mean we all don’t learn from this. If you think the spine might be problematic, maybe removing the spine, or using a smaller size of mullet that the bones will digest a bit better? I like the idea of treating the meat prior to freezing and stuffing with pellets. Do you ever use probiotics or vitamins that you can stuff the mullet with?

 

[kendragon]

So my second thought is that the diet of 99% frozen marine fish could be what was killing them. Perhaps thiaminase. I should have soaked the feed in Vitachem or stuffed pellets in the feed.

Sorry to hear of the loss.
You are the first person I've seen that figured it out.

You already know the answer to the cause of death. This is the very reason I feed Massivore only. I've had this happen and concluded that this type of death is related to nutritional needs of large fish. This will not happen to say fish under 15". The deficiency affects their brain which causes them to weather away. Stuffing pellets in my mind is a losing battle.
In my Dorado tank I started them from day one on Massivore. They are now around 18". I believe I'm going to beat this mystery death. Trying to get them to 24" which to me will be the nail in the coffin. We can debate about it all day but till you have your baby to a good size you will not understand.
Observations: I fed shrimp, smelt and fresh fish fillet in the past. No problems till 15". When problem hits it is too late to change diet.
This mystery death is not exclusive to freshwater fish eating marine diet. This can happen to saltwater fish eating marine diet as well. Big fish raised in outside ponds don't seem to be affected.

It is hobbyist like you that share and stimulate discussion for all to learn from.

 

[Matteus]

Sorry to hear of the loss.
You are the first person I've seen that figured it out.

You already know the answer to the cause of death. This is the very reason I feed Massivore only. I've had this happen and concluded that this type of death is related to nutritional needs of large fish. This will not happen to say fish under 15". The deficiency affects their brain which causes them to weather away. Stuffing pellets in my mind is a losing battle.
In my Dorado tank I started them from day one on Massivore. They are now around 18". I believe I'm going to beat this mystery death. Trying to get them to 24" which to me will be the nail in the coffin. We can debate about it all day but till you have your baby to a good size you will not understand.
Observations: I fed shrimp, smelt and fresh fish fillet in the past. No problems till 15". When problem hits it is too late to change diet.
This mystery death is not exclusive to freshwater fish eating marine diet. This can happen to saltwater fish eating marine diet as well. Big fish raised in outside ponds don't seem to be affected.

It is hobbyist like you that share and stimulate discussion for all to learn from.

So if you are adding supplements and probiotics to the seafood diet will that suffice rather than pellet stuffing? Or just massivore in 5gal tubs....

 

[Yellowcat]

Just saw this, so sorry to see such a dreadful loss of these fish Viktor, I know cephalosilurus are a genus close to your heart. I looked up thiaminase, the effects and lists of unsafe feeder fish and those thought to be safe that don't contain thiaminase, that includes mullet! Other than that I wonder if the salt content in marine fish flesh is higher than fresh water fish but then mullet may have coarse scales or dense bones that may hamper digestion over time? Some sources say tilapia for example, a popular fish food contains thiaminase, some say no? Safe live feeder fish such as bluegills, crappies, some chubs and cichlids, maybe tilapia could be used which may more closely resemble their natural diet than marine fish. There are many other species of fresh and marine fish that could be used from frozen. In general, a wide variety diet is said to be good for man or beast I believe. I realize that live feeders in general have their issues with disease and parasites, impracticability and extra expense. In my experience, most large pseudopimelodid's won't have anything to do with pellets and flakes which would supplant the vitamin B1 in thiamin rich feeder fish unless included inside a frozen fish burrito of sorts, which I've never tried. In my case, ignorance has been bliss (until recently of course) as I've been feeding live goldfish to my pimelodids and pseudopimelodids for decades without any real problems. I still do, with the supplement of live, large night crawlers which they all love. Just mention you're feeding live goldfish to predator fish (Banned in the U.K.) and expect to get flamed by scientific types for sure and I understand why.
Having raised several species of pseudopimelodus, batrochoglanis plus 2 c. apurensis to large sizes on just goldfish and my current c. fowleri for over 12 years on that diet plus the worms, hasn't shown problems, for what it's worth. It's easy in the sense that I keep the tank constantly stocked with a couple dozen goldfish that can be picked off one at at time over a couple of weeks (plus regular hand feeding of night crawlers to my trained c. fowleri and batrochoglanis), a stocked tank is also useful when out of town for a couple weeks as well. O.K., I'm a very bad man...

 

[Deadliestviper7]

Just saw this, so sorry to see such a dreadful loss of these fish Viktor, I know cephalosilurus are a genus close to your heart. I looked up thiaminase, the effects and lists of unsafe feeder fish and those thought to be safe that don't contain thiaminase, that includes mullet! Other than that I wonder if the salt content in marine fish flesh is higher than fresh water fish but then mullet may have coarse scales or dense bones that may hamper digestion over time? Some sources say tilapia for example, a popular fish food contains thiaminase, some say no? Safe live feeder fish such as bluegills, crappies, some chubs and cichlids, maybe tilapia could be used which may more closely resemble their natural diet than marine fish. There are many other species of fresh and marine fish that could be used from frozen. In general, a wide variety diet is said to be good for man or beast I believe. I realize that live feeders in general have their issues with disease and parasites, impracticability and extra expense. In my experience, most large pseudopimelodid's won't have anything to do with pellets and flakes which would supplant the vitamin B1 in thiamin rich feeder fish unless included inside a frozen fish burrito of sorts, which I've never tried. In my case, ignorance has been bliss (until recently of course) as I've been feeding live goldfish to my pimelodids and pseudopimelodids for decades without any real problems. I still do, with the supplement of live, large night crawlers which they all love. Just mention you're feeding live goldfish to predator fish (Banned in the U.K.) and expect to get flamed by scientific types for sure and I understand why.
Having raised several species of pseudopimelodus, batrochoglanis plus 2 c. apurensis to large sizes on just goldfish and my current c. fowleri for over 12 years on that diet plus the worms, hasn't shown problems, for what it's worth. It's easy in the sense that I keep the tank constantly stocked with a couple dozen goldfish that can be picked off one at at time over a couple of weeks (plus regular hand feeding of night crawlers to my trained c. fowleri and batrochoglanis), a stocked tank is also useful when out of town for a couple weeks as well. O.K., I'm a very bad man...

certain species aren't as sensitive to thiaminase as others, for example gars and possibly esox are very tolerant of it, I don't believe thiaminase killed victors fish, I believe this to possibly be to much salt in the diet long term , perhaps causing kidney damage, in humans this can cause weight loss, loss of appetite etc, this is speculation on my part however, I think we need someone in the scientific community to autopsy these fish to determine causative agent in their death

 

[Tripletail]

Hi, have not posted in a very long time ,but I might have something to add. First I am sorry for the loss of your fish.
Lately in florida there have been quite a few red tides on the west coast . Also there are blooms of blue green algae on east coast from too much water being dumped from lake okeechobee. I am not sure if they have been dumping excess fresh water on west coast too, or if you have any problems with blue green algae blooms . There have been alot of cases of dogs getting sick from being in water with the algae and some of the dogs have died. Because you fed the mullet whole or cut up large pieces is it possible there was something like this in the mullets gut ?

 

[Yellowcat]

If I'm not mistaken Viktor fed them frozen mullet. From what I've read, freezing fish will negate any effects if the fish were caught during a red tide situation. I learned a hard lesson many years ago when I had a native fish tank with a largemouth bass and bluegills. I was out ocean fishing here in So. Cal on a sport boat that had live anchovies at the time during a red tide. I took home a bag of anchovies, (hey free fish food) and tossed a few into my fish tank that the bass loved. The next morning everything in the tank was dead, bass and bluegills alike. It was heartbreaking as my pet bass was a very special, interactive character..

 

[Tripletail]

I was mostly thinking about blue green algae in the mullets gut. Does freezing purify algae and make it non toxic ?

 

[thebiggerthebetter]

Thank you all for the great input and ideas to mull over. I will digest and reply in due time.

I was mostly thinking about blue green algae in the mullets gut. Does freezing purify algae and make it non toxic ?

I'd like to know the answer too...

Even though it may be moot to my situation. The mullet I fed to the apurensis, I caught 6-12 months ago. If it had any red tide algae, it is fathomable that they would be from the prior season, although I didn't cast net in the red tide times... but like you said, the mullet might have already eaten a lot of that algae, that is, if it is edible and if it is edible by mullet. Long shot but can't deny it.

Yet Kirk says freezing makes it safe. These mullet have been frozen for 6-12 months. Perhaps the temperature matters. IDK. I freeze all my feed neither deep nor shallow, just an average freeze.