1,000 

 800 

 600 

 400 

 200 



s 



o 150 



o 



o 



- 100 



(r 



^ 50 



q: 



uj o 



m 



s 



3 50 



z 





 20 



10 







HAUL NUMBER 

 (2) 3 4 5 6 7 (8) 9 10 II 112)113)114) 



16 17 lie) 



Primno mocropo 



Cyphocoris chollengeri 



1800 0000 



LOCAL TIME 



0600 



9 JUNE 



Figure 2. — Estimated numbers of amphipods per 1,000 m^ of water 

 strained, as a function of time of day. 



Vinogradov (1957) reported this species from the 

 southwestern Bering Sea. 



Vibilia sp. (V. caeca Bulycheva ?) 



Six specimens in four hauls. Length: 3.6-5.5 mm. 



The identification of these specimens is in question, 

 because of the confused taxonomic status of V. 

 caeca; the original description (Bulycheva, 1955) is 

 sketchy at best. The only other reference to V. caeca 

 (Vinogradov, 1956) differs somewhat from the original 

 description. Also, the distinctions between V. caeca 

 and V. a us trails var. pelagica, which like caeca is 

 eyeless, need to be clarified. 



Paraphronima crassipes Claus 



Two specimens in two hauls, plus one other from 

 the 0.505-mm mesh net in a third haul (no. 13). 

 Lengths: 6.7, 7.1, 8.1 mm. 



Vinogradov (1956) reported the species from lat. 

 59°00'N in the western Bering Sea. 



Hyperia medusarum (O. F. Miiiier) 



Forty-seven specimens in 14 hauls, plus three others 

 from the 0.505-mm mesh net or International Pacific 

 Halibut Commission samples. Length: up to 23.8 mm. 



Bowman (1973) described two forms of this species, 

 /;v5r/7.v-form and mec/usarum-form, based in part on 

 the spine armature of P 1 and P 2; medusarum-form 

 has more and relatively longer spines on S 6 than 

 hystri.x-form. Bowman implies that medusarum-form 

 may be associated with coastal scyphomedusae and 

 //VA7/7.v-form with offshore ones. 



Of the 47 specimens taken in the diurnal study, 30 



can be positively identified as Hyperia medusarum, 

 hystrix-form. One, a 9.2-mm female, seems inter- 

 mediate between the two forms. The remaining 16 

 specimens are too small (^3.9 mm) to be positively 

 ascribed to either form, but they are presumably 

 hystrix-form. Two specimens, both taken by the 

 Halibut Commission in shallow water («15 fm), were 

 identifed as medusarum-form. 



Occurrences and numbers were scattered among the 

 hauls, although they seemed most prevalent at night 

 (Fig. 2, Table 3). 



This species is the most common Hyperia in the 

 eastern North Pacific Ocean (Bowman, 1973). 



Hyperoche medusarum (Kr0yer) 



Three specimens in three hauls. Length: 4.8-5.5 

 mm. 



The species has been recorded from the Arctic 

 Ocean (Shoemaker, 1920; Tencati, 1970); in the sub- 

 arctic Pacific from off the Kurile Islands and in the 

 Okhotsk Sea (Bulycheva, 1955); off southern British 

 Columbia; and in the Gulf of Alaska (Thorsteinson, 

 1941; misnamed as H. leutkeni according to Bowman, 

 1953). 



Parathemisto pacifica Stebbing 



Five thousand six hundred and eighty-nine (5,689) 

 specimens in 17 hauls. Length: up to 8.3 mm. 



The morphologically similar Parathemisto japonica 

 was recently reported from the southeastern Bering 

 Sea (Fukuchi, 1970), although it usually ranges several 

 hundred miles to the west and southwest of here 

 (Bowman, 1960). All of the females examined in the 



HAUL NUMBER 

 7 (8) 9 10 II (I2)(I3)(I4) 



Porolhemisto pocifico 



Pdmno macropa 



Cyphocoris chollengeri 

 Other species 



1200 

 8 JUNE 



-1 — I — I — I — I — I — I — I — I— 

 1800 0000 



LOCAL TIME 



1 — 1 — I — I — 



0600 



9 JUNE 



Figure 3. — Relative abundance and numbers of species of am- 

 phipods per haul, as a function of time of day. 



