Also known as Giant Blue Damselfish, Indigo Damselfish.
Found singly or in pairs in shallow waters, below surf zones over coral and rocky reefs rich in algae growth. Very aggressive and territorial.
They feed on benthic algae, invertebrates and weeds.
Length - 30cm
Depth - 1-5m
Widespread Eastern Pacific
Damselfish are egg layers.
First they clear a site ready for a nest, then engage in a mating dance with rapid swimming and fin movements, during this time the males will often turn a shade or two darker and may display white blotches. Spawning occurs at dawn. Ref: https://www.fishbase.se/summary/Microspathodon-dorsalis.html