Fish Killing Fish

[christie71]

OK my friend has a 20 gal tank with the following fish...( did have anyway )
1 clown loach
1 alage(sp?) eater not sure of the kind
1 alage eater again not sure of kind)
2 platies( blue and red wag)
1 silver $
1 tiger barb
1 dalmation mollie
1 cat fish(kind?)
1 red eyed fish- not tetra

Ok for the past week and a half the fish have been being eaten one at a time... you can tell they have been eaten. with exception of the clown loach (2 month) and the blue plattie(1 month) all have been in the tank together for over a year...
the clown loach then the plattie and then the alage eater have been eaten in that order--
The only aggressive acting fish is the still remaining algae eater but he has been in there for over a year w/o hurting anyone.
Any ideas about this-
thanks!

 

[johnatkin]

Are you certain they were eaten whilst still alive and haven't died and then been eaten? Could do with knowing what sort of catfish it is.

 

[HendrixTheOscar]

If i had to hazard a guess (and dependent upon its species) i'd say it was almost definitely the catfish

 

[catxx]

how big is the algae eater thats still alive? a big CAE would do some damage.

 

[Miss Wiggle]

yeah the chinese algae eaters can be lovely community fish while they're small, as they start getting big enough to do any damage they can then become very agressive and kill other fish. it's entirley possible that it didn't do anything for a year and has now gone on a killing spree these fish can also get to a foot long, way to big for a 20g tank.

depending on what catfish it is that could also inflict some damage, also tiger barbs can be aggressive

 

[dwarfgourami]

Hard to know for sure but my guesses would be (in order of probability):

fish were attacked and eaten by CAE
fish died from water stats problem and were then eaten by almost anyone in the tank
fish were harrassed by tiger barb, died from stress and were then further eaten
fish died from infection and were then eaten

 

[CFC]

Are the fish being killed or actually vanishing from the tank?

If the bodies are left in the tank then it could be anyone of a number of the fish, if they are disapeering i would be suspisious of the catfish.

What type of catfish is it?

 

[Callum]

i reckon you may have a CAE and that will be doing the killing. A.lso silver dollars do better in shoals but your friend would need a bigger tank for a shoal

 

[christie71]

She doesn't know the name of the alage eaters...one I think is a cat fish the other I don't even want to guess-- it has interesting brown and black markings tho if that helps... My guess was the tiger barb too or the cat fish if that is what it is... She said one of the fish was fine and four hours later mangled-- all of them were eatting and happy prior to being found. she is giong to test the water so maybe that is it. thanks soooo much for all the help and ideas!!

 

[Callum]

can you get any photos?

 

[christie71]

i will try...

 

[l.michelle]

I read somewhere once that Chinese Algea Eaters will attach themselves to fish and either leave bad flesh wounds, or kill them

 

[DarkEntity]

All large cats of loaches will do exactly the same, Common Plec are a prime candidate of this.