CLARKE: ECOLOGY OF STOMIATOID FISHES 



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10 20 30 40 50 60 



STANDARD LENGTH(mm) 



Figure 4. — Left: Cumulative size-frequency curves for the 

 pooled catches of Chauliodus sloani (exclusive of individuals 

 over 120 mm) in June 1971 (A, 21 individuals), September 1970 

 (B, 42), December 1970 (C, 13), and March 1971 (D, 19). The 

 curve for the catch in July 1970 (not shown) did not differ 

 significantly from and was almost identical with that for June 

 1971. All other curves differed significantly from each other 

 (P<0.05). Right: Cumulative size-frequency curves for the 

 pooled catches of Astronesthes indicus (exclusive of individuals 

 over 60 mm) in September 1970 (A, dashed line, 20 individuals), 

 December 1970 (A, solid line, 41), March 1971 (B, 128), June 

 1971 (C, solid line, 18), and July 1970 (C, dashed line, 27). All 

 pairs except June-July and September-December differed 

 significantly (P<0.05). 



Stomiatidae 



Four Stomi as danae (55-75 mm) were taken at 

 night. Two were from tows at 100 m and two from a 

 tow at 250 m that extended well past dawn. A 

 larger (154 mm), damaged Stomias sp. was taken 

 in a night tow at 225 m. 



Three specimens (99-290 mm) of the genus Mac- 

 rostomias were taken, but depth information on 

 the samples was questionable for all three. 

 Fedorov and Melchikova (1971) described a new 

 species of Macrostomias, M. pacificus, which 

 they distinguish from M. longiharbatus mostly 

 on the basis of anal fin ray and photophore counts. 

 Two of the specimens I collected had 14 anal rays, 

 and one had 15. Complete photophore counts were 

 possible on only one specimen with 14 anal rays: 

 PV = 81, OV = 82, VAV and VAL = 64. The other 

 specimen with 14 anal rays had PV = 82, OV = 80. 

 The estimated PV + VAV for the remaining 

 specimen was 148. Thus the photophore counts 

 definitely indicate M. longiharbatus, while the 

 anal ray counts fall between those given for the 

 two forms by Fedorov and Melchikova (1971). I 

 suspect that additional specimens will indicate 

 there is only one valid species, M. longiharbatus. 



Astronesthidae 



Astronesthes cyaneus (45; 16-66 mm) 



Astronesthes cyaneus is used here pending 

 further study of the systematics of this species 

 group in the Pacific. The specimens were closest to 

 A. cyaneus as defined by Goodyear and Gibbs 

 ( 1969), but all had rudimentary barbels. Also, the 

 luminous tissue on the operculum of the few larger 

 specimens was not exactly as described by 

 Goodyear and Gibbs. 



Only eight specimens were caught during the 

 day, six of these between 600 and 700 m. Three- 

 fourths of the night catches were at 80-100 m; the 

 few collected deeper were scattered throughout 

 the water column and were probably contamin- 

 ants. None of the specimens were near maturity; 

 only eight were over 25 mm. Larger fish undoubt- 

 edly avoid the trawl and may occur deeper than 

 the small individuals. It appears that even the 

 small ones avoid the trawl during the day. 



Astronesthes indicus (307; 11-117 mm) 



Astronesthes indicus was taken principally at 

 500-800 m during the day and at 30-200 m at night 

 except in the December 1970 series. In that series, 

 no A. indicus were taken in the upper layers at 

 night, but 21 were taken in three night tows at 

 625-750 m, within the day depth range. The 

 numbers collected in these tows were larger than 

 expected if they had been due to contamination 

 and were comparable to catches of day tows at this 

 time. At night, no individual over 50 mm was 

 taken shallower than 125 m, but smaller indi- 

 viduals were taken with roughly equal frequency 

 throughout the night depth range. The small fish 

 also appeared to occur throughout the day depth 

 range, but large fish were taken mostly in tows 

 near the deep end. 



The size composition of the catch varied consid- 

 erably with season and suggested that spawning 

 occurred principally in the summer and fall and 

 that about 2 yr were required to reach 50-60 mm. 

 A few small individuals (< 20 mm) were taken in 

 July 1970, many in September and December, and 

 none in March or June of 1971 (Figure 4B). The 

 small individuals of the September and December 

 samples appear to be represented by a 21- to 

 35-mm group in March and a 34- to 45-mm 

 group in June. A similar sized group, 37-49 mm, 



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