Shortnose Mojarra

Shortnose Mojarra, Diapterus brevirostris

The Shortnose Mojarra, Diapterus brevirostris, whose common Spanish name is mojarra aletas amarillas, is a species in the Mojarra or Gerreidae Family, known collectively as mojarras in Mexico. Globally, there are only four species in the genus Diapterus, and all four are found in Mexican waters, two in the Atlantic and two in the Pacific.

The Shortnose Mojarras have rhomboidal-shaped compressed bodies that have depths that are 48 to 52% of standard length. Their body is silvery white with yellow anal and pelvic fins but with no other distinguishing marks. Their head has a concave upper profile and a concave lower profile. Their mouth is highly extensible, pointing downward when protruded, and their snout is pointed. The lower border of their gill covers is slightly serrated. Their anal fin has long lobes with 3 spines and 8 rays with the second spine being long and thick, their caudal fin has long pointed lobes and is deeply forked, their dorsal fin has long lobes with 9 spines and 10 rays being elevated at the front and featuring a slight notch between the spiny and soft dorsal rays; and, their pectoral fins are long and reach past the anal fin origin. Their lateral line is slightly arched and their head and body are covered with rough scales.

The Shortnose Mojarras reside in shallow coastal areas including mangrove estuaries and fresh water lagoons at depths up to 340 feet. They reach a maximum length of 38 cm (15 inches). They are a poorly studied species and very limited information is available about their behavioral patterns.

In Mexican waters the Shortnose Mojarra are found from Magdalena Bay southward along the southwest coast of Baja, in the southern half of the Sea of Cortez, and along the coast of the mainland to Guatemala.

The Shortnose Mojarra can be confused with the Black Axillary Mojarra, Eugerres axillaris (black anal and pelvic fins) and the Streaked Mojarra, Eugerres lineatus (pectoral fin not reaching anal origin).The Shortnose Mojarras are sold commercially in the major Mexican food stores and are considered an excellent food fish.

Shortnose Mojarra, Diapterus brevirostris, juvenile. Fish caught with a cast net off the pier in Puerto Adolfo Lopez Mateos, Baja California Sur, April 2016. Length: 16 cm (6.3 inches).

f158-shortnose-mojarra-3Shortnose Mojarra, Diapterus brevirostris, juvenile. Fish caught from within the Nautica Marina, Mazatlán, Sinaloa, October 2016. Length: 17 cm (6.7 inches). Catch, photo, and identification courtesy of George Brinkman, Guelph, Ontario Canada.

Shortnose Mojarra, Diapterus brevirostris. Commercial fish courtesy of Soriana’s Market, San José del Cabo, Baja California Sur, April 2008. Length: 17 cm (6.7 inches).

f158-shortnose-mojarra-4Shortnose Mojarra, Diapterus brevirostris. Fish caught within the coastal waters of Magdalena Bay, Baja California Sur, October 2016. Length: 23 cm (9.1 inches).