Chasing unicorns -- fish that is

Unicornfish belong to the surgeonfish family (Acanthuridae).  There are several species of unicornfish that occur here in Hawaii.  We have been trying to photograph two species.

The orangespine unicornfish (umaumalei) has no "unicorn" horn, and grows up to about 18 inches.  Adult males have long filaments running from each corner of the tail fin.  This fish is an adult male.

The buespine unicornfish (kala) has a horn, and grows up to 27 inches.