Dead Otocinclus: Is there a CSI in the house?

[cyndayco]

I bought a healthy-looking Oto, a month after it had "stablilized" in the LFS. Took the usual precautions before releasing it into my tank. After getting its bearings, the oto went right to work on my brown algae.

After 24 hours, I found it hanging onto the glass with its sucker. It couldn't swim anymore, like it was paralyzed. After a short while, it lost its hold and drifted. The oto died soon after.

Tested the water. No ammonia, no nitrites, 10 nitrates. dH was less than 3; very soft. pH was 7.6, like the water in the LFS. Temperature range from 78-82 F. Since the tank had just finished cycling, I had been testing the water almost daily. Everything was consistent.

I examined the body. No unusual markings or lesions. It had a very full stomach. There was some redness around the anal area. But the redness could have been caused by the suction from the filter intake (that's where I found it).

Two cory cats died a few days before the oto arrived. I assumed it was because of malnutrition; they never ate any of the tablets and flakes. I still have 2 small angels, 5 neon tetras and 1 baby molly; all are fine. I don't suspect rough-housing.

My LFS is usually very reliable. The LFS owner said the otos had been there for a month and were quite stable. He fed them zucchini and sinking flakes, to compensate for the low algae supply.

In contrast, my tank is algae heaven. Can otos die of indigestion?

[MDOU]

I have found that ottos are very easily stressed by moving, I have losted a few that way

It could also have somthing to do with the high nitrate, ottos like clean/high quality water.

[Mike_Noren]

"Very full stomach" and "some redness around the anal area" sounds like bloat (bacterial infection of the intestines and body cavity) to me.

Typically plant-eating fish develop bloat after being fed too rich food, which rots in their intestines, especially if they're kept at lower temperatures.

Personally I've only ever seen bloat in two situations: when there's been fish tuberculosis in the aquarium, and within days of feeding frozen bloodworms.
As I once killed off 10 Otocinclus cocama with bloodworms I guess my first question is: what have you been feeding the fish in that tank?

Otherwise, it is unfortunately so that some otos are in such poor shape after starving for perhaps a month after capture before they reach the dealer, and usually starving the whole time in the dealers tanks (as they're unable to compete with other fish for food), that they die very rapidly after being brought home, no matter how well they're treated.

Otos are very sensitive fish, although the fact that they're common and cheap makes people think they're as hardy as e.g. Ancistrus.

Me, I love otos, but basically, under pretty much all circumstances Ancistrus and/or siamese algae eaters is a better choice than otos if all you want is an algae eater. They're bullet-proof compared to otos, much easier to feed, and eat a much wider range of algae.

[cyndayco]

[As I once killed off 10 Otocinclus cocama with bloodworms I guess my first question is: what have you been feeding the fish in that tank?]


Nothing but algae. I did feed the other fishes a little pinch of tubiflex that day, but that was before he was released into the tank. I try not to feed a new fish on Day 1. I give it time to get used to its new home.

[Osmium]

I think Mike has given you an almost 'perfect' answer here. The only thing that I could possibly add is that some Oto's like to hang around in groups (shoal) in groups of more than 5 or 6.

I once learned (from a late coleague), that Otocinclus vitatus are perhaps a wee bit hardier (but don't take 'our' word for it).

Oto's are notoriously difficult to recondition successfully,
but this is perhaps only because no one has bothered to study them properly.

As with any new fish, quarantine them first in a quiet well-planted tank, with lots of hiding places and/or Java moss (Microsorum pteropus), so that they can pick off wee beasties, as they develop their own sense of confidence.

Try to make sure that your own tank conditions closely match that of your charges 'original. If necessary/posssible, 'borrow' several litres of water from your 'source supplier', in order to make the change as gradual as possible.

Don't be afraid to leave the large 'bag' floating within a darkened isolated tank for 24 hours, supplied only with a gently functional airline as company for the fish. A couple of drops of proprietary stress/ammonia-reducing chemicals can always be sneaked in .

Don't even think about feeding them. The first 24 - 72 hours are crucial.

Fish are not 'robots', nor 'performing seals'.

Believe me when I tell you: that it harms me as much to try to teach you this stuff as when and why I first learned it in the first place (the hard way).




Nick

[cyndayco]

At least, you're an experienced aquarist.

I do know how it feels though, to have a newbie preach to another newbie.

[bronzefry]

cyndaco,
In my humble opinion, you've gotten some excellent advice for your problem all the way through!

[cyndayco]

Did I miss something?

I was grateful. Let me say that again. Thank you for your advice, everyone. It was more help than I got at one other forum.

I was merely answering Mike's question. (Look at the quote.)

Then I commiserated with Nick. (See subject heading: "No offense taken. Thanks.")
That was all I said.

Jeez.

[bronzefry]

No problems.