1031 



Abstract. -The whitetip nyingfish, 

 Cheilopogon xenopterus. is an epipe- 

 lagic resident of tropical and subtropi- 

 cal eastern Pacific waters. Its eggs are 

 spherical, average 1.8 mm in diameter, 

 and have an homogeneous yolk and no 

 oil globule. About 53 filaments averag- 

 ing 1 mm in length are evenly distrib- 

 uted on the chorion. The notochord 

 flexes, fin-ray formation is nearly com- 

 plete, and the characteristic larval pig- 

 mentation pattern is established prior 

 to hatching at a larval length of about 

 2.8-3.3 mm. Larvae hatch with pig- 

 mented eyes, functional mouth, and 

 little remaining yolk. Pectoral- and pel- 

 vic-fin rays initially are short but elon- 

 gate rapidly to ca. 25-50^7^ and 20-40'7f 

 of body 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 at 

 about 13-14 mm and cover the body by 

 26 mm. 



The characteristic pigment pattern, 

 visible through the early juvenile stage, 

 consists of the following: melanophores 

 scattered over the mid- and hindbrain. 

 continuing posteriorly as two rows (in- 

 creasing to four or more rows ) along the 

 dorsal margin; a row of melanophores 

 on the horizontal septum of the tail (af- 

 ter hatching); a patch on each side over 

 the hypural area; and two rows along 

 the anal-fin base. Internal pigment is 

 present on the mid- and hindbrain. over 

 the gut. and over the notochord. The 

 pectoral and pelvic fins are sparsely 

 pigmented at hatching and become in- 

 creasingly pigmented with growth. A 

 barred pigment pattern begins to develop 

 on the body at about 8 mm and by the 

 juvenile stage about six bars are present. 



Early life history stages of the 



whitetip flyingfish, Cheilopogon xenopterus 



(Gilbert, 1890) (Pisces: Exocoetidae) 



William Watson 



Southwest Fisheries Science Center 



National Marine Fisheries Service. NOAA 



PO Box 271 



La Jolla, California 92038-0271 



E-mail address billwatsonia'ucsd edu 



Manuscript accepted 20 November 1998. 

 Fish. Bull. 97:1031-1042 ( 1999). 



Flyingfishes, surface-oriented resi- 

 dents of all warm oceans, are well 

 known for their ability to leap from 

 the water and glide over long dis- 

 tances. Flyingfishes can be abundant 

 locally, many are attracted to light, 

 and the gustatory quality of their 

 flesh is generally good (Heemstra and 

 Parin, 1986; Gillett and lanelli, 1991; 

 Parin, 1995). Directed fisheries for 

 flyingfish currently exist, primarily 

 in parts of the Indo-West Pacific and 

 Caribbean; few such fisheries exist 

 elsewhere ( Gillett and lanelli, 1991; 

 Oxenford et al., 1995; Parin, 1995). 

 The family contains eight or nine 

 genera and about 50-60 species 

 (Nelson, 1994; Dasilao et al., 1996); 

 nearly half the species are in the 

 genus Cheilopogon (Heemstra and 

 Parin, 1986). Eggs have been de- 

 scribed for nine Cheilopogon species 

 (Barnhart, 1932; Hubbs and Kampa, 

 1946; Miller, 1952; Imai, 1959; 

 Gorbunova and Parin, 1963; Parin 

 and Gorbunova, 1964; Kovalevskaya, 

 1965; Gibbs and Staiger, 1970; 

 Vijayaraghavan, 1975; Shigonova 

 and Kovalevskaya, 1991; Watson, 

 1996), and at least some larval stages 

 are known for 16 species (Hildebrand 

 and Cable, 1930; Barnhart, 1932; 

 Breder, 1938; Hubbs and Kampa, 

 1946; Imai, 1959, 1960; Gorbunova 

 and Parin, 1963; Kovalevskaya, 1965, 

 1975, 1977, 1982; Vijayarhagavan, 

 1975; Chen, 1987, 1988; Shigonova 

 and Kovalevskaya, 1991; Belyanina, 

 1993; Parin and Belyanina, 1996; 

 Watson, 1996). The purposes of this 



paper are to provide a description of 

 the egg, larval, and early juvenile 

 stages of the endemic eastern Pacific 

 species Cheilopogon xenopterus (Gil- 

 bert, 1890) and to compare these 

 briefly with the early stages described 

 for other Cheilopogon species in the 

 eastern Pacific. 



Materials and methods 



Descriptions are based on 20 eggs 

 and a size series of 45 larvae (2.8- 

 22.8 mm) and 8 juveniles (25.9- 

 44.8 mm). Neustonic eggs and lar- 

 vae and three of the juveniles were 

 collected with Manta nets (Brown 

 and Cheng, 1981) during Marine 

 Mammals Division (Southwest 

 Fisheries Science Center) dolphin 

 surveys in the eastern tropical Pa- 

 cific (Thayer et al., 1988a, 1988b; 

 Lierheimer et al., 1989, 1990; Phil- 

 brick et al.. 1991, 1993 ). The Manta 

 samples were taken nightly from 

 late July through early November 

 or December, 1987-90, and 1992, 

 between about 2-16°N and east of 

 about 115°W. A few juvenile and 

 adult specimens of C atrisignis, C. 

 dorsomaciilata, C. furcatus, C. 

 papilio, C. spilonotopterus, and C 

 xenopterus, radiographed to make 

 fin-ray and vertebral counts for 

 comparison with counts from series 

 specimens, were obtained from the 

 Scripps Institution of Oceanogra- 

 phy Marine Vertebrates Collection 

 (SIO). 



