Ray-finned Fishes of Zihuatanejo

CLASS ACTINOPTERYGII

-Blennies (Order Blenniiformes)

-Pike-Blennies, Tube-Blennies, and Flagblennies (Family Chaenopsidae)

-Genus Acanthemblemaria

-Mexican Barnacle Blenny (Acanthemblemaria macrospilus)

The Mexican Barnacle Blenny (Acanthemblemaria macrospilus) is a small, charismatic saltwater fish found in the rocky and coral reef environments along the Pacific coast of Mexico, including the Gulf of California. They often inhabit empty barnacle shells or crevices in rocks, where they can poke their heads out to observe their surroundings. Feeds primarily on zooplankton (small drifting animals). Also takes mobile benthic crustaceans such as small shrimps and crabs, and will eat pelagic fish eggs and small benthic worms when available. It is endemic to the Tropical Eastern Pacific, restricted to the Mexican mainland coast and nearby islands:

Northern limit: Mazatlán area in the southeastern Gulf of California (Sea of Cortez), including the Tres Marías Islands.
Southern limit: The Gulf of Tehuantepec on the Pacific coast of Oaxaca, Mexico.
It is an inshore, reef-associated species found on rocky reefs, living in empty barnacles and worm/mollusk tubes at 1–15 m.

So its range is a relatively narrow band along the west coast of Mexico, from southern Gulf of California south through the mainland Pacific coast to the Gulf of Tehuantepec.