Black Axillary Mojarra, Eugerres axillaris
Black Axillary Mojarra, Eugerres axillaris. Fish caught within the coastal waters of Magdalena Bay, Baja California Sur, April 2016. Length: 20 cm (7.9 inches).
Black Axillary Mojarra, Eugerres axillaris. Commercial fish courtesy of MEGA Mercado, San José del Cabo, Baja California Sur, January 2012. Length: 21 cm (8.3 inches).
Black Axillary Mojarra, Eugerres axillaris. Fish caught with a cast net off a pier at Puerto Adolfo Lopez Mateos, Baja California Sur, December 2017. Length: 21 cm (8.3 inches). Catch courtesy of Ruben Duran, Puerto Adolfo Lopez Mateos, Baja California Sur. Photograph and identification courtesy of Brad Murakami, Surrey, British Columbia, Canada.
The Black Axillary Mojarra, Eugerres axillaris, is a member of the Mojarra or Gerreidae Family, and is known in Mexico as mojarra malacapala. Globally, there are seven species in the genus Eugerres, of which six are found in Mexican waters, three in the Atlantic and three in the Pacific Ocean.
The Black Axillary Mojarra has a rhomboidal, deep compressed body that has a depth that is 48% to 52% of standard length. The body is silvery in color being darker on the back with thin dark lines along the scale rows on the upper half of the body. They have dark fins and the spiny dorsal has a thin black margin and the inside of the pectoral fin base is dark (for which they are named). The head has a steep straight upper and a concave lower profile, the mouth ends under the front edge of the pupil and the mouth is highly extensible, pointing downward when protruded, and their gill covers are serrated. The head and body are covered with rough scales. Their anal fin has 3 spines and 8 rays and the second spine is long and thick; their caudal fin is forked; their first dorsal fin has 9 spines and is elevated in the front; their second dorsal fin has 9 or 10 rays; and, their pectoral fins are long reaching past the anal fin origin. They have 14 to 16 lower gill rakers and the gill covers.
The Black Axillary Mojarra reside in shallow coastal areas and lagoons at depths up to 30 m (100 feet). They have a maximum of 25 cm (9.8 inches) in length. The Black Axillary 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 Black Axillary Mojarra is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Magdalena Bay, Baja California Sur, southward along the southwest coast of Baja, in the southern half of the Sea of Cortez and along the coast of the mainland south to Guatemala.
The Black Axillary Mojarra can be confused with the Shortnose Mojarra, Diapterus brevirostris (yellow anal and pelvic fins), the Streaked Mojarra, Eugerres lineatus (pectoral fin not reaching anal origin; 11-12 gill rakers) and the Striped Mojarra, Eugerres plumieri (Atlantic Ocean, straight head profile; lacks black spot at pectoral base).
From a conservation perspective the Black Axillary Mojarra is currently considered to be of Least Concern with stable, widely distributed populations. Although they are small in stature they are sold commercially in many of the major Food Markets within Mexico and considered to be an excellent food fish.
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.