Juvenile Sweetlip Jerking Dance

[klausi]

Why do juvenile sweetlips move in such an odd way? I don't think it's anti-predatory, since they don't change location much during their dance. The continuous jerking movement surely must use a lot of energy! Even more curious, the adult fish are very placid. Has anyone done research on this question?

I shot a little video of these fish in Dauin last week:

 

[flyboy08]

They're watching a Richard Simmons video?

 

[Bubblesong]

I got this searching Wikipedia, but it does make sense:They "mimic the movement of a poisonous flatworm for defence against predators. "
Lovely video! Thank you for sharing.

 

[klausi]

Thank you - I guess I somewhat see the similarity. I haven't seen any flatworms where I dive for a long time, and these sweetlip juveniles are everywhere. But I can't get into a predatory fish's head, either.

I got this searching Wikipedia, but it does make sense:They "mimic the movement of a poisonous flatworm for defence against predators. "
Lovely video! Thank you for sharing.