Darkspot Mojarra, Eucinostomus entomelas
Darkspot Mojarra, Eucinostomus entomelas. Fish caught with a cast net off Palmilla Beach, Baja California Sur, March 2015. Length: 14.9 cm (5.9 inches). Catch courtesy of Mauricio Correa, Cabo Real, Baja California Sur. Fish identification courtesy of H.J. Walker, Jr., Scripps Institute of Oceanography, La Jolla, California.
Darkspot Mojarra, Eucinostomus entomelas. Fish caught with a cast net off the pier at Puerto Adolfo Lopez Mateos, Baja California Sur, April 2016. Length: 16 cm (6.3 inches).
Darkspot Mojarra, Eucinostomus entomelas. Fish caught with a cast net off the pier at Puerto Adolfo Lopez Mateos, Baja California Sur, April 2016. Length: 18 cm (7.1 inches).
Darkspot Mojarra, Eucinostomus entomelas. Fish caught within the coastal waters of Magdalena Bay, Baja California Sur, March 2017. Length: 18 cm (7.1 inches).
The Darkspot Mojarra, Eucinostomus entomelas, is a member of the Mojarra or Gerreidae Family, and is known in Mexico as mojarra mancha negra. Globally, there are eleven species in the genus Eucinostomus, and all eleven are found in Mexican waters, seven in the Atlantic and four in the Pacific Ocean.
The Darkspot Mojarra has an elongated oval body with a depth that is 33% to 37% of standard length. Their body is silvery white with juveniles having light tan stripes on the upper side. Their dorsal fin has a black margin. They have a black blotch on their body wall inside the upper corner of their gill covers (after which they are named). Their head has an almost straight upper profile and an enhanced concave lower profile. Their mouth is highly extensible, pointing downward when protruded, and their snout is pointed. They have smooth gill covers. Their anal fin has 3 spines and 7 to 9 rays with the second spine being thick and shorter than the third and the same length as the snout; their caudal fin is deeply forked, their dorsal fin has 9 spines and 10 rays and is elevated at the front; and their pectoral fins are short and pointed and do not reach the anal fin origin. Their head and body is covered with rough scales.
The Darkspot Mojarra is a schooling species and reside in shallow coastal areas including mangrove estuaries and fresh water lagoons at depths up to 100 m (330 feet). They reach a maximum of 24.0 cm (9.5 inches) in length. The Darkspot Mojarra is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Darkspot Mojarra is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.
The Darkspot Mojarra can be easily confused with the Pacific Spotfin Mojarra, Eucinostomus dowii (thinner body; no black blotch inside gill cover).
From a conservation perspective the Darkspot Mojarra is currently considered to be of Least Concern and stable, widely distributed populations. They are small in stature and too rare to be of interest to most.
NOTE. There are eighteen members of the Mojarra or Gerreidae Family currently Included in this website, ten are from Mexican waters of the Pacific and eight from the Atlantic. They are all very similar in appearance and difficult to identify. As an aide to this challenge I have assembled a Mojarra Body Depth Chart that presents these seventeen mojarras from thin bodied to deep bodied which is useful in identification work. In addition, I have also assembled a Mojarra Maximum Length Chart which I have also helpful in the identification work for these eighteen mojarras. Both charts can be found at the end of the Mojarra Family Page.