Narrowhead Flyingfish, Cypselurus angusticeps
Narrowhead Flyingfish, Cypselurus angusticeps. Fish provided by the commercial fishermen in the greater Los Cabos area, Baja California Sur, August 2011. Length: 22.2 cm (8.75 inches). Identification reconfirmed by Eric Lewallen, University of Toronto Scarborough, Toronto, Ontario, Canada.
The Narrowhead Flyingfish, Cypselurus angusticeps, is a member of the Flyingfish or Exocoetidae Family, and is known in Mexico as volador isleño. Globally, there are twelve species in the genus Cypselurus, of which two are found in Mexican waters, both in the Pacific Ocean.
The Narrowhead Flyingfish has an elongated broadly cylindrical body. They are blue-green dorsally and silvery ventrally. Their anal fin is transparent, their caudal fin is dusky, their dorsal fin is pale gray, their pectoral fins are two-thirds red-gray and one-third clear, and their pelvic fins are pale with a dusky spot at the center of the base. They have a short narrow pointed head and a snout of similar length as the eyes. Their mouth is small with the lower jaw being a little shorter than the upper jaw and equipped with a limited number of 3-pointed teeth. Their anal fin originates under the third dorsal ray and has 8 or 9 rays; their caudal fin is deeply forked with a longer lower lobe; their dorsal fin has 12 to 14 rays; their pectoral fins are long and reach past the anal fin base; and, their pelvic fins originate nearer the anal fin origin than the pectoral fin base. Juveniles have one broadly flattened barbel. Their lateral line is low on the body. They are covered with large smooth scales.
The Narrowhead Flyingfish is an oceanic pelagic species found on the surface to depths of 18 m (60 feet). They reach a maximum length of 24.0 cm (9.4 inches). They feed on planktonic organisms and small fish. In turn they are preyed upon by birds, dolphins, dorado, marlins, porpoises, squid, and tuna. They have large pectoral fins and are capable of leaping and gliding considerable distances above the ocean surface. Reproduction is oviparous with the release of large sticky filaments that attach to floating or benthic weeds. The Narrowhead Flyingfish 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 Narrowhead Flyingfish is a resident of Mexican waters of the Pacific Ocean however they have a limited range being found only at the mouth of the Sea of Cortez around the southern tip of Baja, Baja California Sur, and in waters adjacent to Mazatlán, Sinaloa, along the coast of the mainland.
The Narrowhead Flyingfish is not overly straightforward to identify as it looks very much like several other flyingfish. Some can be quickly eliminated due to their dorsal fin ray count which is less than 12. The exceptions are the Blackwing Flyingfish, Hirundichthys rondeletii (anal fin origin under dorsal fin origin) and the Smallhead Flyingfish, Cheilopogon pinnatibarbatus (pelvic fins nearer gill cover than caudal fin base).
From a conservation perspective the Narrowhead Flyingfish has not been formally evaluated. They are seldom seen in North America waters due to their oceanic habitat, however, they are a commercial species in Southeast Asia where they are caught in coastal waters on moonless nights with lights and dip nets.