FISHERY BULLETIN: VOL. 80. NO. 2 



types of copepods eaten by the sternoptychids 

 plus small (8-12 mm) species of euphausiids. The 

 euphausiids were over twice as frequent and, 

 among the copepods, P. xiphias and P. abdomi- 

 nalis much less important in the diet of the 

 larger of the two size groups of fish. Gonostoma 

 atlanticum appears to feed by day (Clarke 1978); 

 as expected, the remains and few intact prey 

 items found in night-caught specimens were 

 similar to those from day-caught fish. 



Gonostoma elongatum were divided into three 

 size groups. Specimens <90 mm SL from both 

 day and night tows (Table 5) contained mostly 

 large copepods, the majority of which were P. 

 xiphias. Euphausiids or their remains were 

 found in several specimens; only one, a Thysano- 

 poda aequalis, was over 10% of the fish's length. 

 Intermediate-sized G. elongatum (93-120 mm 

 SL) were taken only at night, and most stomachs 

 contained only digested remains. The frequency 

 of euphausiids in the diet appeared higher than 

 in the small fish, and one plus the remains of two 

 others were over 10% of the fish's length. Gonos- 

 toma elongatum over 120 mm (Table 6) had eaten 

 large prey in all but two cases. Relative sizes of 

 most measurable items were about 10%, but val- 

 ues ranged from 3.8% to 27% (excluding two cope- 

 pods and a somewhat suspicious pyrosome). 

 Penaeidean shrimps and euphausiids were the 

 most frequent items and remains, but fish were 

 taken by several and squid by two of the large 

 specimens. 



Limited data for G. ebelingi and Diplophos 

 taenia indicated that both diet and differences 

 between size groups were similar to those of G. 

 elongatum, but there were some differences in 

 important prey types. Data for G. ebelingi came 

 exclusively from day tows. Small fish (Table 5) 

 had eaten small zooplankton— Oncaea spp. and 

 ostracods — as well as the larger P. xiphias and 

 euphausiids; the intermediate-sized individuals 

 had eaten only large zooplankton. The largest 

 fish (Table 6) had eaten only fish and crustaceans 

 over 10 mm long; the relative sizes of intact items 

 were 11-24%. Diplophos taenia (Table 5) were 

 mostly from day tows. Small fish had eaten med- 

 ium to large copepods and Euphausia spp. The 

 large fish contained few copepods or their re- 

 mains; most prey were small euphausiids or the 

 large (5-6 mm) amphipod Vibilia spp. The two 

 largest fish examined had eaten myctophids. One 

 of the myctophids (Lampanyctus sp.) and a T. 

 tricuspidata were relatively large (29 and 22%, 

 respectively), but all other items were <10%. 



Astronesthidae 



Astronesthes indicus under 60 mm SL fed 

 mostly on copepods and ostracods (Table 7). 

 Small prey types, especially Oncaea spp., were 

 more frequent in diets of fish under 30 mm SL. 

 Of the two species of scolecithricid copepods 

 eaten, the smaller Scolecithrix danae(ca.. 1.5 mm 

 prosome length) was more frequent in the diet of 

 the fish under 30 mm than in the 31-60 mm fish, 

 but the larger Scottocalanus spp. (over 3 mm PL) 

 were more frequent in the larger fish. Euphausi- 

 ids were only slightly more frequent in the diet of 

 the 31-60 mm fish than in that of the smaller 

 ones; remains of euphausiids, including five in 

 one fish, were found only in the 31-60 mm group. 

 The few individuals over 60 mm SL (Table 6) 

 were mostly empty; only a myctophid and fish re- 

 mains were found. 



The smallest individual of A. "cyaneus" (15 

 mm SL) had eaten small zooplankton, but those 

 20-47 mm SL (Table 6) had eaten only Euphausia 

 spp. — some up to almost one-half their own 

 length. Fish remains were found in two of the 

 three larger fish examined. The small and inter- 

 mediate-sized A. splendidus had eaten a few 

 copepods and a small euphausiid, but all other 

 prey of all sizes were relatively large— an aver- 

 age of 41% of SL— and all but two were fish 

 (Table 6). Small A. "similis" (Table 6) contained 

 only fish remains; the large individuals contained 

 fish and a single euphausiid whose relative 

 length was considerably less than those of the 

 fishes eaten. (See Clarke 1974, regarding differ- 

 ences between the two provisionally identified 

 species and A. cyaneus and A. similis.) 



The items found in Heterophotus ophistoma 

 (Table 6) were unique in several respects, but the 

 significance of these cannot be assessed from the 

 insufficient data here. One of the small speci- 

 mens contained squid remains — otherwise found 

 in only two specimens of G. elongatum. The four 

 large specimens contained two sergestids, a Ster- 

 noptyx sp. — the only nonmigrating fish found in 

 any stomiatoid, and remains of a Parapandalus 

 sp. — the only adult caridean shrimp found. All of 

 these items were relatively smaller than prey of 

 most other nekton-eating species. 



Chauliodontidae 



Chauliodus sloani (Table 6) had eaten mostly 

 fish; only those <120 mm had taken crusta- 

 ceans—mostly euphausiids— frequently. The 



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