Killer in the tank?

[FelixSarduy]

In my 20 Gallon Tank i have 4 Tiger Barbs, 3 Of the fish in the picture which i have derped out and cant remember what kind of Barb they are (Soon to be two), 4 white cloud minnows, 3 guppies (2 female, 1 male), and a Red Tailed Shark. I am almost convinced after the death of a few fish over the past week and a half that my red-tailed shark is killing off my fish (in order, Cory, Chinese Algae Eater, Betta, now this guy). I imagine the algae eater and the other cory where first because they where closer, then two of my these little guys because they where relatively new additions, and where visibly weaker. I am almost sure its him but i also want someone elses input. If we conclude it is him then i guess ill have to move him into my 100 gallon with another shark i have there. Thanks in advanced

http://imgur.com/a/FXWSl

 

[FelixSarduy]

Okay, couldnt get the images up, so heres a link to them on imgur.

Fish - Album on Imgur

 

[Coursair]

Serpae Tetra


Sent from my iPhone using Tapatalk

 

[Brennan32]

I would almost guess the tiger barbs are the ones doing it. I have 10 in a 55 gallon and they wont let me put any other fish in the tank. When i try the attack the fish and rip them apart almost like piranhas!


Sent from my iPhone using Aquarium Advice

 

[Andy Sager]

The cory and Algae eater could be other reasons but the other 2 fish sounds more like the Tiger Barbs than the shark. RT sharks are usually passive but more aggressive towards their own kind. Since these other fish are not direct competition to the shark, there is very little reason for the shark to go after them ( sans possibly the algae eater as it IS competition for food.) Also, Tiger barbs and Guppies don't usually make a good mix as the barbs ( and even the Serpae Tetras) are known to nip their fins.
If it were me, I'd spend a couple of hours in front of the tank just observing the fish's behavior. You should see who the culprit is by then.

 

[Tropical Aquarist]

If it were me, I'd spend a couple of hours in front of the tank just observing the fish's behavior. You should see who the culprit is by then.

Great suggestion, it's even better when the lights are out, many are nocturnal predators!