Pygmy Cory- Mysterious Death

I found one of my 6 pygmy cories dead in the tank last night. Very sad since I love these little guys.

Anyway, I noticed the night before that the bottom half of his caudal fin was gone. There was no visible sign of rot or fungus and none of the other fish show any such signs either.

I did notice that he seemed to be trying to swim into the current from the HOB a lot that night and he was very active in the tank.

His tankmates are:

5 other Pygmy Cories
4 Long finned Zebra Danios
2 Amano Shrimp
4 Ghost Shrimp
3 Danio fry in a breeder net

The breeder net is a pain and taking up more space than I'd like int he already small tank. Could it be that the close(r) quarters are making the normally friendly danios nippy?

Since I saw no signs of illness I can only think of aggression as the cause. Any ideas?

Its possible that he could have been caught between the glass od the aquarium and the breeder net. They like to eat off the net. Maybe he got caught in there in panicked. I hadn't thought of that.

They can't get into the filter I don't think. Its a Penguin 125 in a 10g so the current is pretty strong and the intake has a good cage on it.

Wow. I can't imagine them getting into there but maybe that's what happened.

aquariumfishguy, the breeding net in there has cut way down on the free swim space so I fear it is affecting the behavior of some of the fish.

I'm waiting to get my new fluval in for the 29g and once that happens I can move all the fish but the fry into the bigger tank. Hopefully that will sort things out as I haven't had any such problems before.