Aggressive Fish

[Paulsw]

Earlier today I found one of my female sword tails was dead, having had it's gravid spot eaten out of it, however it did not appear to have any other bits missing. The female was pregnant and I belive she had begun to spawn, and one of my other fish decided that it couldn't wait for the fry to actually be born to eat them, and instead, it would open up the sword tail and eat what it found. This little tale brings me to my question, which fish is the culprit? Other occupants of my tank are;
4 Plecos
2 Chinese Algae Eaters
4 Blue Gouramis
1 Male Betta
1 Red Tailed Black Shark
6 Zebra Danios
3 Remaining Sword Tails (1 Male 2 Female)
10 Harlequin Tetras (I think they are tetras, however I have also found them described as barbs)
1 Tiger Barb
At the moment my suspicions lie with either the Tiger Barb, or the Gouramis, as they are the only fish I belive are big enough to carry this out, as my sword tail was quite large (4.5cm nose to tail).
The Gouramis are not what I would describe as aggressive fish, they normally keep themselves to themselves and go about their business regardless of whatever else is going on in the tank. The Tiger Barb on the other hand can be quite aggressive (I know I shouldn't be keeping 1 barb on it's own however he is also quite large, and since the last of his school died, I haven't been able to find any barbs of a similar size for him to school with) however, I haven't seen this aggression go beyond chasing and fin nipping, and I have noticed that he is more interested in the food tablets I put in for my Plecs/Algae Eaters than he is in either mosquito larvae or other "live" food so it seems unlikely to me that he would go against his normal feeding pattern.

I was wondering if any other members had ever observed behaviour such as this before and if any one could suggest a course of action before another one of my female sword tails falls victim?

Thanks

Paul

[CompMage]

All I can say is I hope that is a 150G + tank!!

Tiger barbs are mean, but not likely to be the one. You should return it if you only have 1. They are mean and will pick on the others if not in a group and will also get sick more easily. Post in the trade area if you want to just get it a good home. Send me a picture if you're in the MD area.

And Blue Gouramis are also VERY aggressive fish. I've seen them kill other fish, but with that many. Their attention should be kept to them self’s.

Rule out the Plecos if they are under 8 inches. But you should return 3 of them. 1 is more then enough for most tanks up to 120G.

Danios attack something...that would be a first

Harequin Tetras...again.....a first

IMO the most likely is the Red Tail. If it saw thre sword tail and mistook it for one of it's own it would attack. They are very territorial. That or anther Sword tail.

Honestly it might have been sick or gotten a parasite.

I count at the lest 70 inches of fish. I really hope this is a massive tank. 55G is not massive.

[Menagerie]

Welcome to AA, Paulsw!

4 Plecos
2 Chinese Algae Eaters
4 Blue Gouramis
1 Male Betta
1 Red Tailed Black Shark
6 Zebra Danios
3 Remaining Sword Tails (1 Male 2 Female)
10 Harlequin Tetras (I think they are tetras, however I have also found them described as barbs)
1 Tiger Barb

That's quite a mix of fish!

one of my other fish decided that it couldn't wait for the fry to actually be born to eat them, and instead, it would open up the sword tail and eat what it found

That would take a lot of thought on the part of the other fish, since it is easier to simply eat free swimming fry. A fish will not expend the energy on something that may not be there.

A little background on the tank would be helpful. When was the tank established? Size of the tank? How big/old is each fish? Etc. I ask because it seems there maybe more going on than just the death of this sword. When did the rest of the school of barbs die? Have your swords had success releasing fry in the past?

[toddnbecka]

It's also possible, actually likely, that the fish was partially eaten after it was dead.