Stegastes diencaeus

Stegastes diencaeus, the longfin damselfish, is a damselfish in the family Pomacentridae from the Western Atlantic. It occasionally makes its way into the aquarium trade. It grows to a size of 12.5 cm in length.^[2] Longfin damselfish have been reported to have a mutualistic relationship with mysid shrimp of the species Mysidium integrum. The interaction is described as a form of domestication with the shrimp providing nutrients for the algae farms the fish feed on and the fish providing protection from predators.^[3][4]

Stegastes diencaeus
juvenile
adult
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Blenniiformes
Family:	Pomacentridae
Genus:	Stegastes
Species:	S. diencaeus
Binomial name
Stegastes diencaeus (D.S. Jordan & Rutter, 1897)
Synonyms
Eupomacentrus diencaeus Jordan & Rutter, 1897 Pomacentrus diencaeus (Jordan & Rutter, 1897) Eupomacentrus mellis Emery & Burgess, 1974 Stegastes mellis (Emery & Burgess, 1974)