Help! Tetra attacking others

SheriLyn

I have had the same 4 tetras together for over 6 months I came home from vacation and one was missing. I later found his remains and yesterday one was swimming funny when I noticed the other tetra was attacking him so I removed the sick one thinking he was hurting him because he was sick. Is it possible that the other tetra is trying to kill the other ones. There all the same breed and like I said have been together for over 6 months.

Thanks
Sheri

1077

Would need to know what species of tetra you have. Some are nastier than others with respect to nipping.
Nearly all tetras behave much more naturally when kept in groups of at LEAST six with a dozen or more being ideal. This would also require appropriate size tank for that number of fish.

SheriLyn

Im not sure what breed thery are because I started taking care of them for my sister when she couldnt take care of them any more. There is a couple links to some photos of them.

http://www.flickr.com/photos/ivythornton/4919209731/

http://www.flickr.com/photos/ivythor...in/photostream




<a href="http://www.flickr.com/photos/ivythornton/4919209731/" title="54 004 by Ivy Thornton, on Flickr"><img src="http://farm5.static.flickr.com/4074/4919209731_fea35a37c1.jpg" width="500" height="375" alt="54 004" /></a>

Byron

Those fish are not tetras (although I have frequently seen them labelled as such in stores), they are Harlequin Rasbora, specifically Trigonostigma heteromorpha. You can read about them in our profiles, just click on the shaded name to see the profile. They behave much the same as tetras (which are characins), so I guess stores think more people will "recognize" the name tetra.

These fish are about as docile as fish can be. All fish are inclined to go after one that is sick/injured, depending upon this and that, so it may be this. This species (and all rasbora) are shoaling fish, just like true tetra, so they need to be in a group of at least 6. Aggression is a common result of being kept in too small a group. Also, shoaling fish will sometimes turn aggressive when they are in too small a space. What is the tank size?

Byron.

CaliforniaFishkeeper

Seen Harlequin Rasboras labeled as Danios/Minnows as well. Literally:
"Harlequin Rasbora Danio."

SheriLyn

Thank you so much for the info! No wonder I couldnt find them any where. There in a 10 gal tank.

Byron

If there are no other fish, 6-7 will be fine in a 10g, preferably planted. They will settle in better with plants around them. Monitor the remaining fish and if they see OK, you could get more to make up a decent sized group.

SheriLyn

There is actually 2 Kuhli Loach and a spotted catfish. I was thinking of giving the Harlequin Rasbora to a pet store if they need to be in a bigger school then just keeping them in a pair.

Byron

Good idea. They are shoaling and they interact with each other so they need to be in a group, in a pinch 5 would be the smallest group I would have. I have 6 of the Trigonostigma espei in one tank and 9 of the Trigonostigma hengeli (both closely related species to T. heteromorpha) in another; both species are almost always together as a group, and as I watch them they are constantly interacting with each other.

Byron.