Cocoa Damselfish

The Cocoa Damselfish is a robust and feisty Caribbean species named for its warm chocolate-brown coloration that can vary from light cocoa to dark brown depending on mood, age, and environmental conditions. Juveniles are particularly attractive, often displaying bright blue dorsal markings and a prominent ocellus (eyespot) near the base of the soft dorsal fin that fades with maturity. Adults reach about 5 inches and develop a solidly built, deep-bodied profile typical of the Stegastes genus.

In the wild, Stegastes variabilis is one of the most abundant and ecologically important damselfish on Caribbean reefs, found from Florida and the Bahamas throughout the Greater and Lesser Antilles to Brazil. Like its close relative the Dusky Damselfish, the Cocoa Damselfish is a dedicated algae farmer that maintains and defends a carefully cultivated patch of filamentous algae within its territory. It aggressively drives away herbivorous fish, sea urchins, and any other organism that threatens its algae garden, creating a fascinating example of farming behavior in a non-human species.

In the aquarium, the Cocoa Damselfish is exceptionally hardy and will survive conditions that would stress most marine fish. Its extreme durability makes it tempting for beginners, but its aggressive territorial behavior must be carefully considered. Adults will claim a section of the tank as their own and vigorously defend it against all comers. A minimum of 50 gallons is recommended, with robust tankmates that can withstand occasional chasing. Despite its aggression, the species is reef-safe and does not harm corals, though it may cultivate algae patches on rockwork.