Pacific Cutlassfish, Trichiurus nitens
The Pacific Cutlassfish, Trichiurus nitens, whose common Spanish name is sable del Pacifico, is a species in the Cutlassfish or Trichiuridae Family, known collectively as sables in Mexico. Globally, there are only three species in the genus Trichiurus, two of which are found in Mexican waters, one in the Atlantic and one in the Pacific.
The Pacific Cutlassfish have extremely elongated and strongly compressed ribbon-like bodies that taper to a point. They have a uniform silvery appearance being darker blue on their upper back and transitioning to silvery reflections ventrally with yellowish transparent fins. Their head has a long snout and large eyes. They have a projecting lower jaw with a large mouth equipped with two or three pairs of large fangs and a series of sharp and compressed lateral teeth on both jaws. Their anus is closer to the tip of the snout than to the tip of the tail and their anal fin has 100 to 105 rays which are exceedingly small and usually embedded in the skin. Their dorsal fin is high and has a long base with 3 spines and 130 to 135 rays. Their pectoral fins are mid-sized. They do not have caudal or pelvic fins. Their lateral line begins at the upper margin of the gill cover, runs oblique to reach behind the tip of the pectoral fins, then continues straight across the ventral contour. They do not have scales.
The Pacific Cutlassfish are a rare and poorly studied species believed to be benthopelagic and amphidromous. They are found in both marine and brackish environments over muddy bottoms of shallow coastal waters and in estuaries from the surface to depths up to 1,260 feet. They reach a maximum length of 1.2 meters (4 feet 0 inches). They are vertical migrators with adults feeding near the surface on fish, squid, and crustaceans during the daytime then retreating to the bottom at night. Juveniles form schools and feed at night on planktonic organisms near the surface then retreat to the bottom during the day. They are known to migrate seasonally to wintering and spawning grounds. Reproduction is via dioecism with each female releasing up to 130,000 eggs per year which are fertilized externally by males. The eggs are scattered on the substrate and the subsequent pelagic larvae hatch in three to six days.
In Mexican waters the Pacific Cutlassfish are found in all waters of the Pacific.
The Pacific Cutlassfish is very similar to the Atlantic Cutlassfish, Trichiurus lepturus (larger eyes; shorter upper jaw; shorter snout) and can also be confused with the Black Snake Mackerel, Nealotus tripes and the Snake Mackerel, Gempylus serpens, both of which have well-defined forked tails.
The Pacific Cutlassfish are generally too rare to be of interest to most but if available are considered “excellent” when fried or grilled.
Pacific Cutlassfish, Trichiurus nitens. Fish caught with the Puerto Los Cabos Marina, Baja California Sur, May 2008. Length: 54 cm (21 inches). Catch courtesy of Eric Brictson, Gordo Bank Pangas, Puerto Los Cabos, Baja California Sur.
Pacific Cutlassfish, Trichiurus nitens. Fish provided by the commercial fishermen of Bahía Kino, Sonora, March 2015. Length: 85 cm (33 inches). Photo and identification courtesy of Maria Johnson, Prescott College Kino Bay Center, Kino Bay, Sonora.