JUVENILE PARROT FISH IDENTIFICATION

[Craig Bonn]

Dear Listers::  I am currently going through fish samples from Puerto Rico,
trying to make positive ids down to the species level.  For the  most part
everything is going good, but I do have some questions about some of the
juvenile parrot fish that are in the collections.  Does anyone know of
someone who could help me with the identification of some of these,
especially those in the genus Sparisoma.  Im having some trouble with S.
radians; S. chrysopterum; and S. rubripinne.  For example, do all radians
have lateral canines after say 30mm?  Is it possible for these canines not
to form until later, or is it possible for them to break off? Many thanks to
anyone that can help.