Are blennies aggressive towards each other?

[Anonymous]

Several months ago I got a blenny (forget what type at the moment...it's late!) to take care of some algae problems. he's been a trooper, but he's not the most attractive of fish--kind of a washed out yellowish grey color. Anyway, he was all the lfs had in the way of blennies for several weeks.

Now I'm thinking about a bicolor blenny or some such. Tank is 125 gal, so there's lots of room--are blennies aggressive towards each other??

 

[Anonymous]

John - I saw pics of that blenny you have. I have the same kind in my tank - I have the scientific name at home but it was sold to me as 'hawaiian sailfin blenny'. Mine chased my midas blenny into the frag tank (he jumped out of the 220 and was ever so lucky to land in that since it's next to the reef) and has gone after my watchment gobies (same color). He does however leave my orangespot blenny and my bicolor alone for the most part. The bicolor and orangespot would be more of a food competitor but he apparently didn't like the midas or the gobies based on color / shape I guess since they were yellow like him. I like mine a lot but am at my capacity on blennies - the midas occupied a nice niche since he was an open water swimmer, the orange spot stays on the substrate mostly and the bicolor is all over bu mostly in the rockwork - I'd try to get one that is not an algae grazer (less chance of being perceieved as food competitor) and is not close in color (so sadly the awesome midas blenny is out, scratch canary blennies too).

A bicolor might work ok - you could try one of the fang blennies like maybe a Meicanthus grammistes which are mostly planktivores. They are not as hardy as bicolors however they will hover in the water column and have a swim bladder unlike most blennies. If you don't have any large fish or crabs a few barnacle blennies would add a lot of character to your tank - they are small but are really fun to watch.

 

[Anonymous]

To the best of my knowledge, there can[/b] some significant intra- and conspecific aggression among blennies. This is not to say it can't work, I've seen plenty of setups where there is nary a problem, just be aware that the possibility is there.