What's Murdering My Fish?

[RipSlider]

OK,

I have a murderer in my tank, and i don't know who it is.

I have a 600l tank. Stocked with

2x firemouth's ( both female )
2x festivum's ( both female )
3x pictus cats
6x congo's
some cory's ( see below )
3 x black widow tetra's
1x royal tiger planque
6x the biggest shrimp in the world - each between 4-6" in size.
4 x golden panchax

In the past week, I have woken up to find at least 1 dead fish every morning.

So far, I've lost
4x corys
1x dwarf green pike cichlid
1x black widow.
3x red clawed crab
I find pieces of them, but I have no idea what's killing them.

In each case, it's like the bodies have been split with a razor. The shrimp have regularly been eating bits of the bodies before I find them in the morning, but they only have very small claws, even though they are impressively big, so I'm tempted to thing it's not them.

There are no sharp edges in the tank, no places for then to get trapped etc etc etc. I checked this over and over again. The filters have debris guards on them, there are no powerheads or properllors etc, so I think it's one of the fish.

In the tank, there is very little that actually eats fish as a preference.

The pike would have done, but it was the smallest fish in the tank.
The firemouths are very peaceful whenever I see them, and trundle along as part of the congo shoal.
The black widows spend most of the day chasing the bubbles from the air stone, which seems to make them pretty cross, but there is no agression there.

The only really "fish eating" things are the tiger planque, but that has it's teritory in the bogwood and never comes out night or day, and the panchax, which attack anything that comes to the surface ( including their keepers fingers!! ) but have no hard "beak" with which to actually do any damage.

Does anyone have ANY idea what the culprit might be?

Steve

 

[tetras4me]

it has to be the fire mouth. even if it seems peacfull. the same thing happend to me onc e a long ways back i kept a few platies with some kind of blue chicled and it thought it was pretty peacful but i finelly caugt the chicled.

anyway even though it appears to be peaceful it probobly the one who doing it.

 

[dizzied]

If your shrimp are longarm shrimps, they could be the killers.

 

[ImperfectFaerie]

I vote for the firemouth. Sorry about your losses!

 

[CFC]

I dont vote for the shrimp, i can pretty much guarentee that it is the shrimp that are killing your fish, so far the majority of the victims have been slow moving bottom dwellers, perfect targets for predatory crustaceans.

I would imagine your shrimps are Macrobracium roesenbergii http/images.google.com/images?hl=en&...rgii&tab=wi which are a large growing highly predatory species and there have been a lot of them in the trade recently.
We once had one of these which we bought for our sons community tank, big mistake as it soon depleted the stock of 11 corys which shared the bottom of the tank with it. I then moved it to one of my tanks with some larger juvinile predatory fish i was growing out, this too was a mistake as it ate a rare and highly prized catfish.

These shrimps should not be mixed with any fish and require a species tank to be kept, they will eventually eat any fish they share a tank with, unless the fish eat them first.

Panaque's are wood eating plecs, they dont eat fish and shouldnt have meat in their diets as it is bad for them.

 

[Tokis-Phoenix]

I would also say its the shrimp, there are a variety of both peaceful and predatory shrimp out there, with the long arm or large claw types generally being predatory- can you get any pics of them?