AHLSTROM: FISH LARVAE IN EASTERN TROPICAL PACIFIC 



cies level, because of lack of pigmentation. It 

 has not been determined yet whether one or 

 more species of Chauliodus occur in the EAS- 

 TROPAC area. Chauliodus larvae were widely 

 distributed, usually occurring singly (50 such 

 occurrences). In only five hauls were six or 

 more larvae obtained per haul; all of these were 

 in the outer patterns occupied by Jordan and 

 Argo. 



9. IDIACANTHIDAE 



( 167 occurrences, 960 larvae) 



It is not known definitely whether one or two 

 species of Idiaca?ithns occur in the eastern Pa- 

 cific; the problem hinges on whether /. pan- 

 amensis is distinct from /. antrostomus Gilbert. 

 Gibbs (1964) considered the two species to be 

 "probably synonymous." In the EASTROPAC 

 area, Idiacanthus occurred more frequently in 

 the northern portion of the pattern, between 

 lat 10° and 20° N, as is shown in Table 13. 



10. OTHER STOMIATOIDEI 

 ( 203 occurrences, 502 larvae ) 



Larvae belonging to thi'ee families are in- 

 cluded as other Stomiatoidei — i.e., of Stomiati- 

 dae, Melanostomiatidae, and Malacosteidae. The 

 most common larva in this category, that of 

 Bathophilus filifer (Garman) (86 occurrences, 

 227 larvae) is separately tabulated in Appendi.x 

 Table 3. Larvae of Eustomius, representing 

 several species, occurred in 17 collections. Lar- 

 vae of Sto7nias were separately tabulated from 

 only eight collections; however, a number of 

 larvae tabulated as unidentified stomiatoid lar- 

 vae undoubtedly are those of Stomias. Accord- 



ing to Gibbs (1969), no fewer than three spe- 

 cies of Stomias occur in the eastern Pacific. 

 Many stomiatoid larvae were poorly preserved, 

 and were not identifiable with any certainty. 



11. SYNODONTIDAE 

 ( 10 occurrences, 41 larvae) 



All but three specimens were taken in the in- 

 ner pattern, occupied by Alaminos. Six of the 

 seven occurrences in this pattern were at con- 

 tiguous stations occupied off" Ecuador and the 

 Gulf of Panama (Fig. 7). Synodontidae are 

 coastal forms. No attempt was made to identify 

 the larvae to the species level. 



12. CHLOROPHTHALMIDAE 



( 1 occurrence, 4 larvae ) 



The only record of Chlorophthalmus larvae 

 was from station 13.052. Larvae in this sample 

 ranged from 5.0 to 6.5 mm long. Pigmentation 

 was limited to a large, single peritoneal pigment 

 patch — and to a few small melanophores on the 

 dorsal and ventral margin of the tail soon be- 

 fore the tip of the notochord. Two larger speci- 

 mens of Chlorophthalmus were taken in the 

 micronekton net hauls, a 23.0-mm specimen at 

 station 14.018 and a 39.5-mm specimen at sta- 

 tion 14.051. Pigment on both was limited to 

 the peritoneal patch, and a midline melanophore 

 over the hypural complex; otherwise both spe- 

 cimens were milky white, without scales. The 

 larger specimen had the following fin counts: 

 D. 11, A. 11, V. 9, P. 17. These are identical 

 to counts given by Garman (1899) for his spe- 

 cies, C. mento from the Gulf of Panama, to 

 which our material probably is referable. 



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