Balistapus undulatus is a common trigger on both seaward and lagoon reefs. They tend to stay close to the bottom and are rather shy. While seen frequently, they often hide before a diver can get close enough for a good photo. Males have a solid green patch on the snout between the eyes and mouth (first three photos below), while in females that area is filled with orange and green bands like the rest of the body (subsequent photos). It is reported to eat a wide variety of benthic invertebrates as well as algae. On one night dive, I found a small B. undulatus being eaten by a piscivorous cone shell, Conus floccatus.
Created 21 May 2012
Updated 11 July 2014