Pacific Argentine, Argentina sialis
The Pacific Argentine, Argentina sialis, whose common Spanish name is argentina del Pacifico, is a species in the family Argentinidae, the Argentines, known as argentinas in Mexico. Globally, there are twelve species in the genus Argentina, of which two are found in Mexican waters, one in the Atlantic and one in the Pacific.
The Pacific Argentines have elongated compressed bodies. They are silvery in color with an iridescent silver stripe along their back. They have a black blotch above their eyes, eight faint dusky bars on their back, and dusky fins. They have a short head with a long pointed snout, a small mouth that opens at the front, and small eyes. Their fins are spineless. Their adipose fin is small and above the anal fin; their anal fin is small with 11 to 25 rays; their single dorsal fin is located at the center of the body with 10 to 14 rays; their caudal fin is strongly forked; their pectoral fins are low on the sides; and their pelvic fins have 10 to 15 rays. They have less than eight short robust gill rakers. Their body is covered with small smooth scales.
The Pacific Argentines are found in coastal waters over soft bottoms at depths between 45 and 3,000 feet. They reach a maximum length of 22.0 cm (8.7 inches). They are found in all Mexican waters of the Pacific with the exception of south of Guadalajara along the coast of the mainland to Guatemala. They are a poorly studied species and very little is known about their behavioral patterns.
The Pacific Argentine is fairly easy to identify due to its body profile and is thus unlikely to be confused with other fish.
The Pacific Argentines are seldom seen by humans; the specimen below is a rather rare catch.