Disappearing/mangled Fish

[425nm]

Soooo I set up a nano tank for a friend and the fish have been diseapearing and/or getting mangled by something. I did a fishless cycle that ran for a month prior to introducing live stock.

The tank:

Fluval chi (tak with out the foutain)

Aquaclear 50 (with polywool and biomax)

Aquaclear 10 powerhead

Fluval stratum topped with exoterra balck reptile sand.

Parameters:

0 NH3

0 NO2

<10mg/L NO3

Temp:

28C

Stocking:

2 cherry shrimp (both disappeared)

2 amano shrimps (One is in perfect condition, other has had his front arms torn off and bits of his tail missing)

2 pygymy corries (one now missing, other in perfect condition)

1 oto (looks like someone tore up his pelvic fins which then got infected subsequently spreading to his abdominal cavity because his intestinal area turned yellow).

It seems like the bigger amano could be the culprit since he has come to absolutely no damage but I've never come across an amano that'd take on a fish (he is however the size of the amano and bigger than the pygmies).

[nanmer]

I have seen amano eat cherry shrimp. Amano would be my guess.

[jvision]

A couple full grown female Ammanos held their own in a 55gal tank with 3 adult sevrums for over a year, once. While I don't really consider them aggressive, if there's not enough to eat in the tank, I'm sure they'll seek out the next easiest meal.

[425nm]

Okay good to know. I'll be sure to let her know to feed them more often. Thanks guys.