The Mojarras (Gerreidae): The Mojarras or Palmitos comprise the Gerreidae Family which has four genera, Diapterus, Eucinostomus, Engerres, and Gerres, with a total of 40 species known globally, of which 11 are found in the tropical Eastern Pacific.

The Gerreidae are silvery fish with moderately deep to slender compressed bodies and distinctively concave vertical head profiles. The snouts are pointed and the mouths extend downward. The Gerreidae have a single dorsal fin that is elevated anteriorly and large rough scales. They are found over sand and mud bottoms, being predators of buried organisms (polychaetes worms and small crustaceans) with the ability to sift sand and debris through their gill openings.

The fish of the genus Eucinostromus have slender bodies with an absence of dark bars on the sides. The anal fins have two spines with eight soft rays with the second anal spine being short. The dorsal fin is equal to or less than the distance from the tip of the snout to the end of the eye. The pectoral fins do not reach the anal fin origin. They have scales that extend in front of the eyes. Globally they are a warm water temperate fish and there are 11 species known globally of which 4 reside in the tropical Eastern Pacific, each of which is found in Mexican waters.

The fish of the genus Gerres have deep bodies with 6 to 10 indistinct faint bars on the sides. The anal fins have three spines with seven soft rays with the second anal spine being longer than the tail base is deep. The second dorsal fin spine is shorter than the distance from the tip of the snout to the end of the eye. They have pointed pectoral fins that are long and reach past the anal fin origin. They have a deeply forked caudal fin.

There are 28 members of this Genus found globally, but only one in the tropical Eastern Pacific which is also present in Mexican waters.

Among the Mojarras found in Mexican waters, the four currently represented in the fish section of this website include: the Graceful Mojarra, Eucinostomus californiensis; Pacific Flagfin Mojarra, Eucinostomus currani; Peruvian Mojarra, Diapterus peruvianus; Silver Mojarra, Eucinostomus dowii; and Yellowfin Mojarra, Gerres cinereus.