AHLSTROM: KIND AND ABUNDANCE OF FISH LARVAE 



Protomyctophum sp. 



(25 occurrences, 44 larvae) 



For most kinds of myctophids, the distribu- 

 tional patterns of larvae are so similar in the 

 two multivessel EASTROPAC survey cruises 

 that distributional information from ETP II 

 merely reinforced that obtained on ETP I. Dis- 

 tribution of Protomyctophrim larvae affords an- 

 other example of this. All but two of the occur- 

 rences lie between lat 10°N and 5°S, the zone 

 in which all Protomyctophum larvae were ob- 

 tained on ETP I. As noted in Ahlstrom (1971) , 

 the larvae were all of a kind, belonging to a per- 

 haps undescribed species of Protomyctophum, 

 subgenus Hierops. Wisner (1971) described 

 two new species of Protomyctophum, subgenus 

 Hierops from the eastern Pacific: P. chilensis 

 from off Chile about lat 33 °S and P. beckeri from 

 the vicinity of the Hawaiian Islands. It is not 

 known as yet whether the form from EASTRO- 

 PAC is referable to either of these. 



Symbolophorus evermanni (Gilbert) 

 (155 occurrences, 822 larvae) 



Larvae of Symbolophorus were absent from 

 a wide coastal strip off Mexico and a narrower 

 coastal strip off Peru, but were taken at most 

 stations in the remainder of the ETP II pattern. 

 The distribution was rather similar to that il- 

 lustrated for ETP I (Ahlstrom, 1971, Figure 

 12); the frequency of occurrence was slightly 

 lower on equivalent ETP I (37% positive hauls 

 versus 44%), but the average abundance per 

 haul was slightly higher (2.6 versus 2.3 larvae). 

 However, in the ETP I stations without counter- 

 parts in ETP II, frequency of occurrence was 

 higher than in the remainder of the ETP I pat- 

 tern (63% versus 37%) and average abundance 

 per haul was higher (4.5 versus 2.6 larvae). 



Triphoturus spp. 



(144 occurrences, 824 larvae) 



Larvae of Triphoturus oculeus (Carman) 

 were taken in most hauls made between lat 5°N 



and 15 °S off Ecuador and Peru and offshore to 

 the vicinity of the Galapagos Islands. Larvae 

 of this species, which appear to be more exclu- 

 sively restricted to the transition waters of the 

 Humboldt Current than are those of other myc- 

 tophids sampled in the EASTROPAC pattern, 

 also may exhibit the most marked seasonal 

 change in relative abundance. Other Tripho- 

 turus larvae, sampled mostly offshore, were tak- 

 en in slightly lesser abundance than on ETP I. 



16. PARALEPIDIDAE 

 (247 occurrences, 2,535 larvae) 



Larvae of Paralepididae ranked sixth in 

 abundance and contributed over 2% of the total. 

 Larvae were taken throughout the ETP II pat- 

 tern, but most commonly in an equatorial band 

 between lat 5°N and 5°S; all collections of lar- 

 vae exceeding 25 larvae per haul were obtained 

 from this band. Fewest larvae were taken in 

 the southern portion of the inner pattern, below 

 about lat 7°S. Because of limited coverage of 

 the South Pacific central water mass on ETP II, 

 no material was obtained of Sudix atrox Rofen 

 (see Ahlstrom, 1971, Figure 7 for distribution 

 of larvae of this species on ETP I) . A detailed 

 study of the species composition of the paralep- 

 idid material from EASTROPAC surveys has 

 not been made. 



17. SCOPELARCHIDAE 

 (134 occurrences, 298 larvae) 



Larvae of Scopelarchidae were taken through- 

 out the area surveyed on ETP II. As noted for 

 ETP I (Ahlstrom, 1971, p. 32-33), larvae of five 

 or six kinds of scopelarchids were obtained, 

 usually in small numbers per haul. On ETP II, 

 only 6 of 133 positive hauls contained over 5 

 larvae (6 to 12 larvae), and over 80% of the 

 hauls contained 1 to 3 larvae per haul. 



18. SCOPELOSAURIDAE 



(40 occurrences, 390 larvae) 



Larvae of Scopelosauridae were taken in more 



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