Stegastes diencaeus (Jordan & Rutter, 1897)

Taxonomy and Nomenclature

Stegastes diencaeus, commonly known as the longfin damselfish, is a member of the damselfish family Pomacentridae that is native to the Western Atlantic.

Human Use and Size

This species occasionally enters the aquarium trade, and reaches a maximum length of 12.5 cm.

Interspecific Relationship

Longfin damselfish are known to have a mutualistic relationship with the mysid shrimp species Mysidium integrum.

Mutualism Details

This interaction is classified as a form of domestication: the shrimp supply nutrients to the algae farms that the fish rely on for food, while the fish protect the shrimp from predators.