Need Help!! Blenny Attacking Butterfly

I am new to this forum, and did not know where else to turn for some advice. We have a lawnmower blenny that is literally attacking our spot-banded butterflyfish. The blenny waits on top of the rock for the butterfly to swim by and takes a bite out of his side or fins. This has been happening for 2 days now. We don't want to get rid of either fish, but do not know what else to do. I thought blennies were supposed to be docile fish?

We have a 55 gal aquarium, with 2 clowns, 2 neon gobies, 1 firefish, and 1 angel along with the blenny and butterfly. tank has been established for 5-6 years now.

Thanks

 

Try moving around some of your live rock. Often fish that act territorial (Clowns, Clowns, and well Clowns) will stop being territorial after a landscaping change.

 

The clowns are not a part of the problem. If we move around the rocks, is it going to matter with the blenny, being he is an algae grazer and will go to all the rocks? This fish just perches himself on top of the rocks and waits for the butterfly to come swimming past. He even corners him in the tank, to where we have to go in to move the blenny away.

 

Not really. I don't know if there is any other solution to your problem besides removing one of the fish.

 

Blennies can be very aggressive to fish they preceive to be a threat to their resources, i.e. food. My guess is the butterfly either resembles a tang to the blenny and is assumming its another herbivore(yes this CAN happen-fish are smarter than we think) or the butterfly picked on the rock looking for inverts, and the blenny assumed THIS behavior was the butterfly BEING herbivorous, again threatening the blennies resources.
The problem is two fold, if you don't take out a fish the butterfly will most likely get bullied to death or at least stress him enough that something else does him in...
Your other problem is this, if you get rid of the butterfly, unless you INTENTIONALLY keep you tank full of ALGAE the blenny will slowly starve to death. I have never seen a blenny in captivity-other than "dirty" tanks live long term. Two years is tops. I have gone to the extent in my tanks years ago to leave drapes open to let the sun hit the tank, never wipe down the glass, extend the photoperiod, all in an attempt to increase diatom and other algal growth. The sheets of dried he would eat but not enough to keep him going...
Just letting you know....

Good luck and happy decision making!

 

Thanks for all your help. It was unfortunate, but we had to remove the blenny. We feared that he was going to kill off the butterfly as his attacks were just getting worse. Thanks again.

 

Good move. I find once a fish starts getting territorial, you are best to find him a good new home. No one likes a bad roomate.

 

+1 Common misconception with blennies.

 

Sorry about your blenny... fish can be stupid sometimes. Have you gotten rid of it yet? Because one thing you could try, as someone said above, would be to quarantine the blenny for a few days and move the rocks around a little to try and get rid of the territorial behaviour, then put the blenny back in and see what happens.

Kristyn

 

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