733 



Abstract-The stomach contents of the 

 minimal armhook squid iBerryteuthis 

 anonychus) were examined for 338 

 specimens captured in the northeast 

 Pacific during May 1999. The speci- 

 mens were collected at seven stations 

 between 145-165°W and 39-49°N and 

 ranged in mantle length from 10.3 

 to 102.2 mm. Their diet comprised 

 seven major prey groups (copepods, 

 chaetognaths, amphipods. euphausi- 

 ids, ostracods, unidentified fish, and 

 unidentified gelatinous prey) and was 

 dominated by copepods and chaeto- 

 gnaths. Copepod prey comprised four 

 genera, and 86% by number of the 

 copepods were from the genus Neo- 

 calanus. Neocalanus cristatus was the 

 most abundant prey taxa, composing 

 50% by mass and 35% by number of 

 the total diet. Parasagitta elegans 

 (Chaetognatha) occurred in more 

 stomachs (47%) than any other prey 

 taxon. Amphipods occurred in 19% of 

 the stomachs but composed only 5% by 

 number and 3% by mass of the total 

 prey consumed. The four remaining 

 prey groups (euphausiids, ostracods. 

 unidentified fish, and unidentified 

 gelatinous prey) together composed 

 <29c by mass and <1% by number of 

 the diet. There was no major change 

 in the diet through the size range 

 of squid examined and no evidence 

 of cannibalism or predation on other 

 cephalopod species. 



Diet of the minimal armhook squid 

 (Berryteuthis anonychus) 

 (Cephalopoda: Gonatidae) 

 in the northeast Pacific during spring 



Kazuhisa Uchikawa 



National Research Institute ot Far Seas Fisheries 

 5-7-1 Shimizu-Ondo 

 Shizuoka, 424-8633, Japan 

 E-mail address stomyctS affrc go ip 



John R. Bower 



Northern Biosphere Field Science Center, Hakodate Branch 



Hokkaido University 



3-1-1 Minato-cho, Hakodate 



Hokkaido 041-8611, Japan 



Yasuko Sato 



Department of Agriculture, Forestry and Fisheries, Nngata Prefecture 



Agriculture Affairs Division 



Shlnko-cho 



Nngata 950-8570, Japan 



Yasunori Sakurai 



Graduate School of Fisheries Sciences 

 Hokkaido University 

 3-1-1 Minato-cho, Hakodate 

 Hokkaido 041-8611, Japan 



Manuscript submitted 2 September 2003 

 to the Scientific Editor's Office. 



Manuscript approved for publication 

 29 June 2004 by the Scientific Editor. 



Fish. Bull. 102:733-739 12004). 



The squid family Gonatidae plays 

 an important role in the ecosystems 

 of the North Pacific. In the Sea of 

 Okhotsk, the annual production of 

 gonatid squids is more than half that 

 offish production (Lapko, 1996), and 

 in the western and central Bering 

 Sea, gonatid production is thought to 

 exceed that of the dominant fish fami- 

 lies (Radchenko, 1992). In the sub- 

 arctic North Pacific, the gonatids are 

 an important link in the pelagic food 

 web iBrodeur et al., 1999). To better 

 understand the food web in the North 

 Pacific and the processes influencing 

 the production of gonatid squids in 

 this region, information is needed on 

 the feeding behavior of these squids. 

 The minimal armhook squid iBerry- 

 teuthis anonychus) (also known as the 

 "smallfin gonate squid" [Roper et al., 

 1984]) is a small gonatid (maximum 

 mantle length = 150 mm) distributed 

 mainly in the northeast Pacific (Rop- 



er et al.. 1984: Bower et al., 2002). It 

 is a major prey for fishes, squids, sea- 

 birds, and marine mammals (Ogi et 

 al., 1980; Pearcy et al., 1988; Pearcy, 

 1991; Kuramochi et al., 1993; Pearcy 

 et al., 1993; Ohizumi et al., 2003) but 

 is not targeted by any fishery. Despite 

 the importance of B. anonychus in the 

 food web of the subarctic North Pa- 

 cific, the only published reports on 

 its feeding behavior are two abstracts 

 in the Russian literature (Lapshina, 

 1988; Didenko, 1990). In this arti- 

 cle, we provide further information 

 on the feeding behavior of B. anony- 

 chus by describing the diet of a wide 

 size range of squid collected from the 

 northeast Pacific during late spring. 



Methods 



Berryteuthis anonychus was collected 

 during a United States National 



