AHLSTROM: FISH LARVAE IN EASTERN TROPICAL PACIFIC 



in micronekton hauls, has shown the presence 

 of five kinds. Larvae of B. bathymaMer Jordan 

 and Bollman had the most limited distribution, 

 being a coastal species, but were taken in the 

 largest numbers. Two species occurred in the 

 central water mass of the South Pacific (B. 

 japonicus Tanaka, and perhaps B. macclellandi 

 Thomp.son). Another species occurred in the 

 equatorial current system, and a fifth species 

 was widely distributed between lat 7° and 20° 

 N. One or both of the latter may be unde- 

 scribed. 



26. EXOCOETIDAE 

 (78 occurrences, 189 larvae) 



The species composition of flyingfish larvae 

 has not been worked out in detail as yet. Only 

 larvae of the most common species, Oxijpor- 

 hamphus micropterus (Cuvier and Valencien- 

 nes) (.51 occurrences, 121 larvae) have been sep- 

 arately tabulated (Appendix Table 3). Larvae 

 of Oxyporhamphus were taken at a number of 

 stations in a coastal band off Mexico and central 

 America. Offshore occurrences were limited 

 to an equatorial band between lat 5° S and 7° N. 

 Only one occurrence of larvae of this species 

 was obtained to the south of lat 5° S. Exo- 

 coetid larvae undoubtedly are undersampled in 

 oblique plankton hauls, both because of their 

 shallow depth distribution and their marked 

 swimming ability. Much more material of exo- 

 coetids — eggs, larvae, and juveniles — are pres- 

 ent in surface plankton hauls; only a few of 

 these have been sorted as yet from EASTRO- 

 PAC L 



28. GEMPYLIDAE-TRICHIURIDAE 

 (103 occurrences, 231 larvae) 



The larvae of these two families are grouped 

 together for reasons discussed below. Larvae of 

 four species of gempylids-trichiurids appear to 

 be widely distributed in the eastern Pacific: 

 these are Nealotus tripes Johnson (42 occur- 

 rences, 82 larvae. Fig. 7), Gempylus serpens 

 Cuvier and Valenciennes (40 occurrences, 57 

 larvae, Fig. 13), Diplospiniis rmdtistriatus Maul 

 (26 occurrences, 62 larvae, Fig. 14), and Lepid- 

 opus sp. (7 occurrences, 25 larvae, Fig. 14). 

 Records of the occurrence of these in EASTRO- 

 PAC hauls also are given in Appendix Table 5, 

 and summarized in Table 19. One or two speci- 

 mens each were taken of larvae of two or three 

 additional species of gempylids-trichiurids. 



Late larval stages already have been described 

 for three of the above species (Voss, 1954; 

 Strasburg, 1964), but early developmental 

 stages have not been described, except for a 

 species of Lepidopus. We plan to describe the 

 early stage larvae of all the above species. 



The larval series of these four species raise 

 questions about the distribution of genera be- 

 tween these two families, and perhaps, about 

 the need for two families. Larvae of Diplospi- 

 niis nmltistriatus are quite similar to those of 

 Gempylus serpens. This similarity is marked 

 enough to have led Voss (1954) to describe the 

 larvae of Diplospimis as those of Gempylus (i.e. 

 her Gempylus A). Her Gempulus B larvae are 

 those of Gempylus serpens. 



Table 19. — Summary of occurrences and relative abundance of species of Gempylidae-Trichiuridae in the four 



vessel patterns occupied on EASTROPAC I. 



35 



