Blackwing Flyingfish, Hirundichthys rondeleti
Blackwing Flyingfish, Hirundichthys rondeletti. Fish provided by the commercial fishermen in the greater Los Cabos area, Baja California Sur, November 2010. Length: 7.0 cm (2.8 inches). Identification reconfirmed by H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, California.
The Blackwing Flyingfish, Hirundichthys rondeleti, is a member of the Flyingfish or Exocoetidae Family, and is known in Mexico as volador ala negra. Globally, there are seven species in the genus Hirundichthys, of which five are found in Mexican waters, one in the Atlantic, one in the Pacific and three, including this species, that are found in both the Atlantic and the Pacific Oceans.
The Blackwing Flyingfish has an elongated cylindrical body. They are iridescent blue dorsally and silvery ventrally. Their anal and pelvic fins are transparent; their caudal and dorsal fins are dusky; and their pectoral fins are black with a narrow clear margin. Juveniles have a clear dorsal fin with a dark outer blotch and black pectoral and pelvic fins. They have a short head, a short blunt snout, and a small mouth with conspicuous conical teeth on the sides of each jaw which are of equal length. Their anal fin has 11 to 13 rays and originates under the dorsal fin; their caudal fin is deeply forked with the lower lobe being significantly larger than the upper lobe; their dorsal fin has 10 to 12 rays; their pectoral fins are set high on the body and extremely long reaching beyond the anal fin origin; and, their pelvic fins are long, reach past the anal fin origin, and are nearer the anal fin origin than the pectoral fin base. They are covered with large smooth scales. Their lateral line is low on the body.
The Blackwing Flyingfish is an oceanic pelagic species found on the surface to depths of 20 m (65 feet). They reach a maximum of 30 cm (12 inches) in length. 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 Blackwing 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 Blackwing Flyingfish is a resident of all Mexican waters of the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean. In the Pacific they are found in all waters except they are absent from the extreme northern portion of the Sea of Cortez.
The Blackwing Flyingfish is fairly similar to and can be confused with several over flyingfish. Several of these can be eliminated by the position of the anal fin which in many similar species is found well behind the dorsal fin. One exception is the Bladewing Flyingfish, Hirundichthys marginatus (transparent dorsal fin; 3 bars on side).
From a conservation perspective the Blackwing Flyingfish is currently considered to be of Least Concern with stable, widely distributed populations. They are seldom seen by humans and due to their rarity, they are of limited value and interest to most.