[hitmanx]

Long story short:

One week ago I added 3 Oto cats to my 2 month old heavily planted 15 gallon, with plenty of algae... 1 died within an hour with what looked like internal bleeding, another looked sick by day 2 and by day 3 the Amano shrimp had him cleaned to the bones, but the smallest of the lot seemed to eat happily away... he was doing fine until yesterday when i noticed, he has darkened up, his top fin is clamped, and he's missing half his tail fin... his belly looks normal, but he seems more subdued

This is my first time with Oto cats so i am at a loss... any ideas as to whats happening?

Other fauna includes 8 CPDs, 18 RCS, 7 Amanos shrimp, 3 Tiger shrimp, 1 apple snail


Edit: I forgot to mention the Amano shrimp seemed to hunt the other sick Oto cats while they began to get sick... i caught 2 of them actually on top of the first struggling Oto eating away at its back :confused1:

Do Amano shrimp normally hunt slow and sick fish? Could they have jumped the remaining Oto as he slept and caused these fin injuries?


Tested yesterday:

gh 26
kh 14
ph 8.0
no3 20-40ppm
no2 0
nh4 0 (the 10th had a 0.25ppm spike from the dead fish)

Fertilizer: Flourish NPK, once per week
Temp: 24*C

 

[Diana]

That tail does look bitten, not rotted.

Perhaps one of the problems is the hard, alkaline water. However, there is something attacking the Oto, IMO.

 

[hitmanx]

Well it's now a moot point... the Oto cat has succumbed to whatever the problem was... same symptoms as the other two... maybe it was the hard alkaline water and and the fact that they come from soft acidic locations... and I guess that probably rules out pygmy corys too

I'll stick with hardy shrimp like cherries and amanos to do my algae clean up ...

 

[philipraposo1982]

u also needed to have a minimum of 6. sounds like unhealthy fish though.