Two mysterious manglings!

[Tachometer]

I'm not sure why or how this is happening...but it's happened twice now.

I've got a 30 gal planted tank. For filters I have a Penguin 170 and a Fluval 104.

Fish:
6 glow light tetras
6 black neons (now 4!!)
6 otocinclus
1 large ghost shrimp (about 1-1/2 inches long)

Water testing shows excellent water quality, no bad stuff at all.

Within a week of adding the neons I found a floater...he had been cut in half, the tail section missing. I found him after work and he had obviously been dead a while.

Then just today (about 3 weeks later) I am feeding and see another black neon with his tail section missing. The poor little guy was still alive and the damage looked very fresh...but obviously he wasn't going to last so I took him out and...disposed of him.

There aren't any big fish that could do this...and I highly doubt the shrimp is responsible.

My only guess is that they are getting caught in one of the inflow tubes to the filters and getting their back half chopped off. Ow! The black neons are bigger than the glow lights...and I haven't seen any of them stuggling against the water flow...but that's all I can think of.

Any thoughts out there? I'm so sad!!

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[125gJoe]

http://gordon.sourcecod.com/images/flagicons/american_flag.gif
Saltwater crabs are known for this - especially at night. It's possible a large freshwater shrimp could do this at night, when the fish sleep and don't expect an attack. Filtration would not cause this.

[Tachometer]

I guess it could be the shrimp...he's pretty big and active...but those black neons don't seem to hang out around him. I mean the shrimp tends to be a bottom guy, the neons middle ground...

And both times it happened it was during the day. I looked at the tank in the morning and all was good. I come home from work and a neon is dead.

I'll just have to keep an eye out.

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