My silver arowana in 4500 gal
- Thread starter thebiggerthebetter
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PS: #2 of the three silver arowanas currently in my care was particularly fast-growing & aggressive, & well outgrew his grow-out tank @>20".
So I moved him in with #1, whom we were thinking was the female - kind'a even-tempered erring to docile at a heavy-bodied ~30" in her outdoor 6x15' x 6' deep pond with filamentous plants, lilies, native mullet & swordtails, so plenty-habitat & a light flow.
She'd stripped 20% of his scales & pretty much sleeved his tail before i got home from work. He was upright & somewhat-swimming so I moved him into a huge tupperware & found a taker in the next town, but he didn't make the night. Bloody shame, though he was a bit of a dickhead & likely picked the fight...
Take-home lesson on more-than-one: heaps of space. If there's any question, get more space... or less fish.
So I moved him in with #1, whom we were thinking was the female - kind'a even-tempered erring to docile at a heavy-bodied ~30" in her outdoor 6x15' x 6' deep pond with filamentous plants, lilies, native mullet & swordtails, so plenty-habitat & a light flow.
She'd stripped 20% of his scales & pretty much sleeved his tail before i got home from work. He was upright & somewhat-swimming so I moved him into a huge tupperware & found a taker in the next town, but he didn't make the night. Bloody shame, though he was a bit of a dickhead & likely picked the fight...
Take-home lesson on more-than-one: heaps of space. If there's any question, get more space... or less fish.
Wow, that is quite a fish enclosure! And here I am impressed by myself and my 500!
A peer from Sri Lanka sent me a couple videos where younger silver arowana stick head out of water, shake, jitter, convulse, and thrash, then may recover for some time or a moment, then probably repeat. He says the fish stop feeding.
TBTB: Hi Hasitha, I've never seen this before. I can only guess that this might be consistent with a brain seizure or something related that's acting upon the brain and/or central nervous system.
HJ: I’ve met so many arowanas doing this. But when asking about their diet. Mainly they have been eating Thiaminase rich food like prawns.
TBTB: Then therein likely lies your answer, IMHumO. Among the many symptoms of the vitamin B1 deficiency, one main consequence is the effect on brain and nerves. We've met with this in our experience, as you know, with various fish. Now, our arowana losses in 2020-2021 (see above in this thread), in retrospect, could have been from the thiaminase issues as well (as we most obviously found out in Oct-Nov 2022). Our arowana didn't show the violent symptoms of sticking head out of water, shaking, and thrashing like shown in your videos. Some of ours got badly swollen, others lost the ability to keep the balance and swim right, some displayed both. One possible explanation for the difference in the symptom expression could be that our arowana were quite mature 5-10yo, while I presume that your experience could have been confined to juvi or sub-adult arowana, still growing, with their brains and nerves still heavily developing, so the B1 deficiency could express a bit differently in them.
TBTB: Hi Hasitha, I've never seen this before. I can only guess that this might be consistent with a brain seizure or something related that's acting upon the brain and/or central nervous system.
HJ: I’ve met so many arowanas doing this. But when asking about their diet. Mainly they have been eating Thiaminase rich food like prawns.
TBTB: Then therein likely lies your answer, IMHumO. Among the many symptoms of the vitamin B1 deficiency, one main consequence is the effect on brain and nerves. We've met with this in our experience, as you know, with various fish. Now, our arowana losses in 2020-2021 (see above in this thread), in retrospect, could have been from the thiaminase issues as well (as we most obviously found out in Oct-Nov 2022). Our arowana didn't show the violent symptoms of sticking head out of water, shaking, and thrashing like shown in your videos. Some of ours got badly swollen, others lost the ability to keep the balance and swim right, some displayed both. One possible explanation for the difference in the symptom expression could be that our arowana were quite mature 5-10yo, while I presume that your experience could have been confined to juvi or sub-adult arowana, still growing, with their brains and nerves still heavily developing, so the B1 deficiency could express a bit differently in them.
A question for you please, Victor. Fifty arowana is a healthy number and I'm guessing that all were not silver. Of those that you've had can you put a rough percentage on the number of silvers you've had that developed D/E? Have you had any black arowana and of those did any develop D/E?
I've had a dozen or so (mostly black in recent years) over the last 50 years, ballpark. All the silvers developed D/E and none of the black. Do you have a perspective on D/E in general and assuming your percentage of silver vs black w/ D/E is significantly different do you have a theory as to why that is?
I have a theory myself but I like to think I'm not too old to learn.
All the roughly 50 were silvers. No other species. All had a drop eye of some sort, some even in both eyes, various severity. About 40-45 were rescues that came with a drop eye, one or both. We raised 5-10 from little babies to adulthood ourselves and these didn't develop a DE until the breeding behavior started with all the fighting, jumping and hard hitting walls, braces, lids, etc. with theirs heads, so I believe these DEs could be a result of physical trauma.
Blacks are prohibitively expensive, probably b/c wild caught, and there is a hypothesis that even among silvers wc don't or are less prone to develop a DE vs farm raised. Unfortunately they don't come stamped so telling wc from cb is not easy.
As you know there are other hypothetic explanations for the DE - lighting, diet, fat pouch, looking up to feed, looking down to keep track of feed and tank mates.
Blacks are prohibitively expensive, probably b/c wild caught, and there is a hypothesis that even among silvers wc don't or are less prone to develop a DE vs farm raised. Unfortunately they don't come stamped so telling wc from cb is not easy.
As you know there are other hypothetic explanations for the DE - lighting, diet, fat pouch, looking up to feed, looking down to keep track of feed and tank mates.
