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Guide to Sea of Cortez Fish Species

Sea of Cortez 810

Guide to travel, activities, organisms, and ecology of the Sea of Cortez

Giant Damselfish
Microspathodon dorsalis

Sea of Cortez Giand Damselfish Microspathodon dorsalis


Description and Size
To 12 inches (305mm) 
The largest of the Gulf damselfishes, adult giant damselfish are typically grey, silver, or blue in coloration.  Dorsal, anal, and caudal fins all have trailing streamers.       

Identifying Features
Besides their size, giant damselfishes are best identified by the trailing filaments from the tips of their fins. 

Central Sea of Cortez, south throughout Central America and the Galapagos. 

Rocky shores, especially large boulder regions just below the surge zone to 40 feet.  

Behavior and Ecology
Unlike most other Sea of Cortez damselfishes, the giant damselfishes are primarily herbivorous. These damselfish establish large territories both for breeding, as well as cultivating the algae on which they feed.  During breeding season, it is common to see males displaying a dramatic bicolor motif, with the front half a bright white and the back half a dark blue or black.

Back to Pomacentridae 

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Updated August 28, 2009

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