CLARKE: ECOLOGY OF LANTERNFISHES 



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20 40 60 80 

 STANDARD LENGTH (mm) 



Figure 7. — Cumulative size-frequency curves for samples 

 of Lciinpcinyctus niger collected at different depths at 

 night. Top: December 1970 — two samples from 750 m 

 of 119 and 174 individuals (A); 320 m, 10 (B): and 

 250 m, 39 (C). Bottom: June 1971—140 m, 60 individuals 

 (A): 165 m, 12 (B); 185 m, 41 (C); 260 m, 14 (D); and 

 300 m, 25 (E). 



The calculated totals indicated for both day 

 and night series that L. niger was most abundant 

 during December 1970; the figures for other 

 series were all similar and about one-half of 

 those from December 1970. Except for slightly 

 higher percentages of smaller (<40 mm) fish in 

 December and September 1970, there were no 

 distinct differences in the calculated size 

 frequencies. The percentages of mature females 

 with developed ova for both December 1970 

 and March 1971 were significantly higher than 

 those for June 1971 and September 1970. 

 Together these data indicate that L. )iige)- 

 spawns principally in the early part of the year 

 and that most of the juveniles are recruited 

 to the trawlable population by December. 



NOTE (Added in press) 



The name LatnpaiiyctKs niger, used above, 

 included both individuals with weakly developed 

 pectoral fins and those without pectoral fins. 

 Recently, M. A. Barnett informed me that, in 

 specimens collected north of Hawaii, there are 

 differences in other features which correlate 



with the presence or absence of pectoral fins. 

 All of our specimens have been reexamined and, 

 regrettably, there appear to be at least two 

 forms present. The taxonomic status of these 

 forms cannot be evaluated. A world-wide 

 revision of species of the Lampcutyctu.s niger- 

 ater-achirus complex will be necessary to fully 

 elucidate the problem (cf. Nafpaktitis and 

 Nafpaktitis, 1969). Consequently, the text above 

 was left unaltered, and the following supple- 

 mentary data is offered here. The latter must be 

 regarded as tentative since it was impossible 

 to identify all specimens with certainty due to 

 damage during collection. 



Roughly one-half the specimens have no 

 pectorals. These, designated as Form A, also 

 differ from the others in that the PVO2 photo- 

 phore is well separated from PVOi and above 

 the level of PO4. The SAO3 is usually posterior 

 to AOai, and AOa + AOp is 5-6 (rarely 4) 

 + 6-7 (rarely 8) = 12-13 (rarely 11). Form 

 A appears to reach maturity at about 57-58 

 mm and reaches a maximum size of 74 mm. 



In the remaining specimens, the pectoral 

 fin was variously developed but always present. 

 The PVO2 was closer to PVOi and at or below 

 the level of PO4. SAO3 was usually anterior to 

 or above AOai. The majority of these had AO 

 counts of 5(4) + 6(7) - 11. These, Form B, 

 reached maturity at about 70 mm. and the 

 maximum size was 84 mm. Among the speci- 

 mens with pectorals, the eleven largest indi- 

 viduals (85-125 mm) and about two percent 

 of the smaller ones had higher AO counts — 

 5-6 + 6-7 (rarely 8) - 12-13 (14). None of 

 these larger fish were mature, suggesting the 

 presence of a third form, Form C. 



Thus there appear to be two very similar 

 forms that were common and roughly equal in 

 abundance and a larger, much rarer form. The 

 depth distributions, migrations, size-depth pat- 

 terns, and seasonal changes of Forms A and 

 B are quite similar and essentially as described 

 above under Lampa)iycti(ti niger. The co- 

 occurrence in abundance of two such similar 

 forms contrasts with the patterns of most other 

 closely related species. Further investigation 

 of not only the taxonomic status, but also the 

 geographic distribution of these forms will be 

 necessary to determine if, as with the Hygophum 



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