Butterfly Flyingfish, Cheilopogon papilio
The Butterfly Flyingfish, Cheilopogon papilio, whose Spanish common name is volador mariposa, is a species in the family Exocoetidae, the Flyingfishes, known collectively as voladores in Mexico. Globally, there are 24 species in the genus Cheilopogon, nine of which are found in Mexican waters, four in the Atlantic and five in the Pacific.
The Butterfly Flyingfish have elongated broadly cylindrical bodies. They are blue-green dorsally and silvery ventrally. Their anal fin is transparent and their dorsal fin is dusky. Their pectoral fins are black with clear narrow margins and tips. Juveniles have black dorsal fins and two fused black barbels under their chin. They have a short head, a short blunt snout, and a small mouth equipped with small teeth having one point. Their anal fin originates under the third dorsal ray and they have nine or ten rays (a key to identification); their caudal fin is deeply forked with the lower lobe being significantly larger than the upper lobe; and their pectoral fins are long, set high on the body, and reach beyond the anal fin origin. Their pelvic fins originate far back on the body closer to the caudal fin than the gill cover and reach past the anal fin origin. Their lateral line is low on the body. They are covered with large smooth scales.
The Butterfly Flyingfish are an oceanic pelagic species found on the surface to depths of 65 feet. They reach a maximum length of 22.2 cm (8.7 inches), with this upper limit established by the fish photographed below. They feed on planktonic organisms and small fish. In turn they are preyed upon by birds, dolphins, dolphinfish, 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. They are found in all Mexican waters of the Pacific with the exception of the northern half of the Sea of Cortez and the entire west coast of Baja.
The Butterfly Flyingfish is not overly straightforward to identify as it looks very much like several other flyingfish. Some of these can be quickly eliminated by their dorsal fin ray counts, as the Butterfly Flyingfish has at least eleven. The others include the Blackwing Flyingfish, Hirundichthys rondeletii (anal fin origin under the dorsal fin origin), the Panamic Flyingfish, Prognichthys tringa (pelvic fins nearer gill cover than caudal fin base), the Sailor Flyingfish, Prognichthys sealei (white dorsal fin), and the Smallhead Flyingfish, Cheilopogon pinnatibarbatus (pelvic fins nearer gill cover than caudal fin base).
The Butterfly Flyingfish are seldom seen by humans. Due to their rarity, they are of limited value and interest to most.