balancer (in CC amphib glossary)

[fishkeeper]

definition here. Photo definitely needed...I know there are several good ones out there.

 

[Mark]

Rod like structures on each side of the head designed to stop larva sinking into sediment or losing their balance. Once the forelimbs develop the balancers either break off or degenerate.

I may have better photos but here's one that sort of shows them.

 

[Jennewt]

I'm going to remove the word "designed", lest we spark some heated debate on evolution and design!

Does anyone know whether these structure break off, reabsorb, or degenerate? I'm going to take the easy way out and say disappear:

Balancer: Rod-like structures on each side of the head of newly-hatched larvae. The balancers stop the larva from sinking into sediment or losing its balance. Once the forelimbs develop, the balancers disappear.

 

[Mark]

Thanks Jen.

Duellman and Trueb say "break off or degenerate". I personally would have thought they would be re-absorbed. Disappear is probably safest!