Fish mystery - Who is the evil culprit???

Question

I have a 20 gallon tank with 10 female and 3 male guppies,a male pineapple swordtail,long finned danios,a cherry barb,SAE and peppered cories.I also have a pair of small mollies and unexpectedly the male got torn and bitten on his body.I have a cover over the tank so nothing outside could disturb them.Who in the world in my tank could have done it???

The population of fish in the tank have been calculated accurately so there is no such thing as overcrowding.I have added salt as mollies need salt to survive.I think that the swordtail is the culprit as he is lonely.What do you think?

(Cherry barbs are not aggresive, and it is the most peaceful fish I've ever had!And he have only been eating in my tank, that's all)

Please don't blame my cutie barb please!!!

Answer 1

Let me guess, the attack happened more than likely at night?
The barbs are semi aggressive, and will pick on other fish, especially at night if you don't have a big enough group of them. If you have a number of them, they take out their aggression on each other.
Possibility number two. The danios did it. Danios LOVE to terrorize other fish at night. Most people don't realize it is them doing it because they leave everything alone while the lights are on.
In your tank, lights go out, and havoc starts, combine that with overcrowding and there not being enough territory for the fish to claim as their own....nothing but trouble.

Answer 2

I have cherry barbs.. they're harmless against other fish... They might nip at a tail once in a while but they're not attacking a fish..

It's your SAE (siamese algae eater)... A SAE is semi-aggressive but I bet you really don't have a SAE.. You have a false SAE or even a chinese AE... They're territorial and turn carnivorous when they get older.

and yes, I think You're overcrowed too.
I'm not a big fan of the 1 inch / 1 gallon rule... It'll get you by but it won't let your fish thrive...
try the 1 inch/ 6 square inch of water surface rule.

ps. i love my cherry barbs too...

Answer 3

Unless you're positive you have a SAE, my vote is solidly with him. And if he's much bigger than about 4", call me 100% sure. ;) Fake SAEs get meaner and meaner as they get older. The nipping turns to eating when they get big enough... be careful with your tank!

(If it's a true SAE, then my second choice is the swordtail. I've seen aggressive ones before.)

I'm including a source page with good illustrations of the different types of algae eaters. See if you can figure out which one yours is for sure and that may solve the mystery.

Answer 4

I'd say the barb is the chief suspect. They can be pretty nasty in my experience. If I keep barbs, I prefer to keep a tank of ONLY barb species - that way, other fish are less likely to be injured, and barbs can generally defend themselves against other barbs.

Answer 5

Being a small fish, the mollie could be prone to be picked on in general. Still, sorry, based on temperament of the various fishes I'd go with Cutie.

Answer 6

I would say the sword fish. I use to had some of guppies and red sword fishs in the same tank. A few days later all the guppies either die or tail torn.
Is sword fish like the fighting fish?

Answer 7

The barb. Barbs are semi-aggressive, I had some rosy barbs that tore each other and my gourami to shreds. I had to give up on barbs and stick with gourami, they're nicer.

Oh, and I agree- you're WAY overcrowded.

Answer 8

I vote for the barb in the library with the candlestick.

Answer 9

barbs are notorious for nipping fins....but swordtails are noted for being real bullies

Answer 10

I agree - its the SAE. Mine used to terrorize my guppies. I had to get rid of it.