Early life history stages of the whitetip flyingfish, Cheilopogon xenopterus (Gilbert, 1890) (Pisces : Exocoetidae)

The whitetip flyingfish, Cheilopogon xenopterus, is an epipelagic resident of tropical and subtropical eastern Pacific waters. Its eggs are spherical, average 1.8 mm in diameter, and have an homogeneous yolk and no oil globul e. About 53 filaments averaging 1 mm in length are evenly distributed on th e chorion. The notochord flexes, fin-ray formation is nearly complete, and the characteristic larval pigmentation pattern is established prior to hatc hing at a larval length of about 2.8-3.3 mm. Larvae hatch with pigmented ey es, functional mouth, and little remaining yolk. Pectoral- and pelvic-fm ra ys initially are short but elongate rapidly to ca. 25-50% and 20-40% of bod y length, respectively. A pair of mandibular barbels form at about 4 mm and fuse mesially at about 8 mm. Scales begin to form along the lateral line a t about 13-14 mm and cover the body by 26 mm. The characteristic pigment pattern, visible through the early juvenile stag e, consists of the following: melanophores scattered over the mid- and hind brain, continuing posteriorly as two rows (increasing to four or more rows) along the dorsal margin; a row of melanophores on the horizontal septum of the tail (after hatching); a patch on each side over the hypural area; and two rows along the anal-fm base. Internal pigment is present on the mid- a nd hindbrain, over the gut, and over the notochord. The pectoral and pelvic fins are sparsely pigmented at hatching and become increasingly pigmented with growth. A barred pigment pattern begins to develop on the body at abou t 8 mm and by the juvenile stage about six bars are present.