Choelo Halfbeak

Choelo Halfbeak, Hyporhamphus gilli

The Choelo Halfbeak, Hyporhamphus gilli, whose Spanish common name is pajarito cholo is a species in the Halfbeak or Hemiramphidae Family, known collectively as pajaritos in Mexico. Globally, there are thirty six species in the genus Hyporhamphus, six of which are found in Mexican waters, three in the Atlantic and three in the Pacific.

The Choelo Halfbeaks have elongated cylindrical slender bodies. They are silvery brown dorsally with dark-edged scales and silvery ventrally and on their sides. Their upper back has three narrow dark stripes and their mid-flank has a distinct gray stripe with a black upper border. Their snout and beak are black with a red tip. Their fins are transparent to dusky. Their lower jaw extends into a relatively short beak that is less than twice the head length and their upper jaw is short and triangular. They have no teeth. Their anal fin has 15 to 18 rays and originates behind the dorsal fin; their caudal fin is moderately forked with the lower lobe being larger than the upper lobe; their dorsal fin has 14 or 15 rays; their pectoral fins are short and high on the sides; and their pelvic fins are on the abdomen well back on the body with the origin being closer to the pupil than to the caudal fin base. They have 37 to 50 gill rakers. Their anal and dorsal fins are well back on the body with bases opposite each other. Their lateral line is low on the body and they are covered with large smooth scales.

The Choelo Halfbeaks are a pelagic species normally found in coastal waters on the surface to depths of 20 feet. They reach a maximum length of 21.0 cm (8.3 inches). They feed on planktonic organisms and small fish. In turn they are preyed upon by birds, dolphins, dorado, marlins, porpoises, squids, and tuna. Reproduction is oviparous with females releasing large eggs containing a sticky substance that allows the eggs to attach to floating debris.  Although fairly common in some areas, they are a poorly studied species and very little is known about their behavioral patterns.

In Mexican waters the Choelo Halfbeaks have a limited distribution being found from Guerrero Negro southward along the central and southwest coasts of Baja, in the southern half of the Sea of Cortez, and along the coast of the mainland south to Guatemala.

The Choelo Halfbeak can be easily confused with the California Halfbeak, Hyporhamphus rosae (caudal fin modestly forked), the Longfin Halfbeak, Hemiramphus saltator (25 to 32 gill rakers), and the Pacific Silverstripe Halfbeak, Hyporhamphus naos (caudal fin modestly forked).

The Choelo Halfbeaks are fairly rare in the greater Los Cabos area and unable to survive a panga bait tank making them poor live bait and therefore of limited value to most.

Choelo Halfbeak, Hyporhamphus gilli: Fish provided by commercial bait salesmen from Puerto Los Cabos, Baja California Sur, September, 2007. Length: 18 cm (7.1 inches). Fish identification reconfirmed by H.J. Walker, Jr., Scripps Institution of Oceanography, La Jolla, CA.