Blackstripe Herring, Lile nigrofasciata

Blackstripe Herring, Lile nigrofasciata. Fish caught with a cast net off a pier in Puerto Adolfo Lopez Mateos, Baja California Sur, April 2016. Length: 9.0 cm (3.5 inches).

The Blackstripe Herring, Lile nigrofasciata, is a member of the Herring or Clupeidae Family and is known in Mexico as sardinita raya negra. There are four global members of the genus Lile, and all four are found in Mexican waters, one in the Atlantic and three in the Pacific Ocean.

The Blackstripe Herring has a deep compressed body with a convex lower profile and a depth that is 24% to 28% of standard length. They are yellow-green dorsally and transition to white ventrally. They have a dark green dorsal stripe and a wide silver stripe on their sides. The tips of their caudal and dorsal fins are black. Their anal, pectoral, and pelvic fins are translucent with a yellow tinge. Their eyes have a black iris and a white to translucent pupil. The inside of their gill cover is dark. Their head has a pointed snout and a small oblique mouth that opens at the front. Their anal fin has 14 to 16 rays and is short originating behind the dorsal fin; their caudal fin is deeply forked; and, their dorsal fin has 13 to 17 rays and originates even or before the pelvic fins. They have 29 to 32 gill rakers. Their body is covered with large scales.

The Blackstripe Herring is a small pelagic coastal schooling species that reside along sandy and muddy shores and  also in brackish waters and high salinity estuaries at depths up to 2 m (6 feet). They reach a maximum of 13.0 cm (5.1 inches) in length and are virtually weightless. The Black Stripe Herring 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 Blackstripe Herring is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Magdalena Bay, Baja California Sur, northward along the central and northwest coasts of Baja and in the northern third of the Sea of Cortez.

The Blackstripe Herring is most likely confused with the Graceful Herring, Lile gracilis (dorsal fin behind pelvic fins; caudal lobes without black tips) and the Striped Herring, Lile stolifera (deeper body; wider mid-body stripe).

From a conservation perspective the Blackstripe Herring is currently considered to be of Least Concern with stable, widely  distributed populations. They are exceedingly rare, small in stature and of limited interest to most. Quality photographs of this species are non-existent and the identification of the fish presented above should be considered tentative.