algae eating fish - can they attack???

Slime not skin

I understand they are attacking the slime coat, not actually eating the fish.

Of course, this allows parasites and bacteria to enter the skin and then the fish gets sick and may die.
Typically the story starts, "I don't know why my goldfish is so sick he has these red sores on him, the scales seem to have come off. The other one died." I read one thread where the poster was sure the pleco was not involved, until one night he saw him stuck on the goldfish.

Not that goldfish are all that nice, I've also read, "Help, help, the cory catfish is stuck halfway down the goldfish's throat with the spines holding him in place, which one should I try to save?"

I even see my oto following the zebra danios around like he'd like to suck up to him, but the zebras are too fast and the oto gives up.

FWIW, I gave up on goldfish, too difficult, I'll stick to tropicals and plants until I am a lot better at this aquarium stuff.
 
Any suckermouth catfish may attach to and eat from the slime coat of any fish wide- or flat-bodied enough for it to be done. BUT, >95% of the time, the sucker-mouth is not being adequately or properly fed.

CAEs are a different group of fish, they do change their diet as they mature.

Any large grazing animal or fish may become territorial as they mature and develop the mass in relation to tankmates to exercise that attitude.
Territorial fish should be kept together only with awareness of the keeper that it may not work.
 
This is interesting because a lady came into the store and actually said the algea eater (chinese BTW) ripped open the side of the goldfish. I thought this wasn't possible, adding more hiding places would help? but I see my algea eater brawl with my kribs....so I learnt a few lessons...but I don't think they attack to the point of death....I thought in only extreame cases...
 
I have a 4" CAE in with a Green Terror, a Juvi firemouth, juvi JD, a juvi texas, and with a 5" Pimelodus pictus. I used to have two CAE's in one tank but they fought constantly, and I do mean constantly. CAE attack behavior consists of ramming not attaching to the fish, but they will attach to fish as well. My CAE killed 7 tigerbarbs in the course of a week. Now my GT seems to keep him in check and he turns tail and runs anytime he they cross paths but he brawls with my pictus who is a tough son of a B as well.
 
how did he

kill your tiger barbs did he actually suck onto them and just pull them down n eat them or what??? just curious i think this is an interesting thread!!!
 
Well I am not 100% sure that he was killing them, but they all died in a 7 day span, 1 a day for 7 days. I think that when they would sleep is when they would fall victim. I lost several to a red clawed crab as well. I would either find them floating with thier mouths open, or I would find them at the bottom with a CAE attached to them. This is the only clue I had as to thier deaths. But if he could he would have killed that other CAE. He had about starved him to death so I went out and picked up a 10 gallon the put the other CAE in. He now resides in my 55 gallon with a pair of convicts and another firemouth.
 
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