[sanjay]

hi i got a new fish tank but after some days i noticed that one fish died and i doubt that it has been killed by another fish(big one).is it really possible?

[sanju123]

Yes this could be one of the possible reasons. Usually what happens is that some fish don't get together well and the bigger fish tend to hurt the frail one,it could have been fatal in your case.

[cirereyes]

One thing you should remember is that, fast swimmers have to be with fast swimmers. Same is true with slow swimmers and carnivores. Never mix a slow swimmer with a fast swimmer like a gold fish and a tiger barb is not compatible, tiger barbs will just eat up the tail of the gold fish.