Why are my Otto's dying?

[Hunter2001]

Over the last two weeks, I have had 2 of 5 Otto Algae Eaters die on me. I orininally had two and one of them died, so I purchased 3 more and another just died today. The one today wasn't quite dead when I noticed it in my aquarium. It was Floating upside down and having a terrible time trying to swim. I watched it for a while and it became apparent it was moments away from death, it sank to the bottom and did not move, so I removed it from my aquarium. I'm not sure if the one that died today was one of the original two I bought, or if it was one of the three I recently bought.

I have had my aquarium running for about 3 months now and all of my other fish are fine. My 29 gallon tank consists of:

10 Neon Tetras
6 Zebra Danios
3 Albino Cory's and now,
3 Otto's

I believe my water quality is OK, its crystal clear, I change about 10% every 2 weeks. The Ph is about 7.5, which has been maintained since the beginning.

If anyone has any thoughts as to why my Otto's are slowly dying off, I would greatly appreciate it.

Thanks.

[Slappy*McFish]

Probably sickly and stressed out when you bought them.

[Rometiklan]

Ottos are fairly sensitive when you first bring them home. I would spend more time acclimating Ottos than I normally would with another species of fish. Make sure the water in your tank and the water in the shipping bag are as close as possible before you release the fish. I spend anywhere up to an hour, pouring minute amounts of tank water into the shipping bag over the course of an hour to let the Otos adjust slowly. Once an Otto has acclimated to your tank, they do very well..it's the first week or so that is fairly critical. Also, I would quarantine the Ottos first before I introduce the fish to my main tank.

It also wouldn't hurt to re-test your water conditions. I would also test the water in the shipping bag.

[JVal]

I used to have trouble with the little guys too. Some would die about a week after I got them. I lenghtened the acclimation time to an hour and a half at most. Go very slowly and watch them for signs of stress.

[wetmanNY]

cut 'n paste from www.skepticalaquarist.com :

Why newly-arrived Otos can die like flies.
Otocinclus are notorious for dying like— well, like Otos—when you first get them home, though once they've acclimated to your planted tanks they live for years. Aquarists beat themselves up over this, but I think it's not our fault. Here's the thing: no vertebrate vegetarian can digest cellulose, not one! so each carries a species-specific community of anaerobic bacteria (and some protozoans) that do the work. Ruminants even have a special fore-stomach (the rumen) where grass is fermented in a rich bacterial soup, protected from stomach acids. Dairy cows are nourished, not so much by grass, but by bacterial by-products, which include some vitamins, and by digesting some bacteria (how ungrateful!). Now, look at the size of the Oto. Scarcely room for a billion gut bacteria in there to do the work, eh? Starved Otos in transit can lose so much of their gut bacteria that the internal ecosystem doesn't revive— even with a glut of tasty algae in your tank! It just passes through their system, like when you were too hasty eating that corn-on-the-cob, remember? Not much nutrition when the kernels passed right through, because your system couldn't digest them open. Otos need a jungley tank with lots of leaf surfaces to run over. But the vegetable supplement we give them (zucchini, spinach, etc.) isn't just a treat. It has to be constant, or else they won't have the gut bacteria to process the green treat when it finally does arrive. Hopefully with your algae, and plenty of natural green cover, and your constant feedings of spirulina flakes or algae wafers plus veggies every few days, Otos that aren't too far gone should thrive with you. Females are noticeably wider and plump, but though a healthy male is leaner, he shouldn't have a concave look, when seen from the side.

SegaDojo recently offered the suggestion that Otos might be unusually sensitive to nitrate. That might go far to explain Otos' sensitivity. "As a rule," G. Sterba wrote in 1967 (in Aquarium Care, p. 257) "newly imported wild-caught fish from tropical waters poor in nitrate and nitrite are particularly sensitive."

[Hunter2001]

Thanks for the info wetmanNY, that was both awesome and impressive!

[mt_marcy]

I'd like to add in a thank you as well. This new information will get me more ahead of my "research on Ottos, as I'm considering adding some to my tank in the near future... Thanks,
mt_marcy!
P.S- anyone else know of any good tips on keeping ottos?

[Slappy*McFish]

Indeed...ya learn something new everyday:) ...great info.