Swim bladders?

[messy_da_legend]

Do the lurker puffers actually have swimbladders? I was just wondering, as they seem to spend most of thir time on the bottom, although, they also seem to have no trouble hanging in mid water flapping away?

[sstimac]

Yeah, they have swim bladders.

[nmonks]

You could probably hazard a guess that they have reduced swim bladders compared with midwater species like Colomesus asellus. It is very, very common for fishes that have adopted a benthic lifestyle to have smaller (or entirely absent) swim bladders. For benthic fish, the advantages of a swim bladder aren't there in terms of saving energy swimming, and on the other side of the coin being heavier helps them stay in one place, reducing the chance of the current carrying them away from their lair.

Cheers, Neale