Cephalopods of the South Georgia slope Martin A. Collins* P , A. Louise Allcock O and Mark Belchier* *British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 OET. O School of Biology and Biochemistry, Queen’s University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL. P Corresponding author, e-mail: macol@bas.ac.uk During January 2003 the bathymetric distribution of the cephalopod fauna of the South Georgia and Shag Rocks slope (100^900 m) was investigated using a commercial bottom trawl. Forty-four trawl stations caught 193 cephalopod specimens including six species of octopod and seven of squid. The benthic octopods Pareledone turqueti and Adelieledone polymorpha were abundant in shallow water at South Georgia, being replaced by Thaumeledone gunteri in greater depths. However, neither A. polymorpha nor T. gunteri were caught on the adjacent Shag Rocks area. Two specimens of the deep-sea genus Graneledone were caught on the South Georgia slope.The most abundant squid species caught were Moroteuthis knipovitchi, Psychroteuthis glacialis and Slosarczykovia circumantarctica, which are primarily pelagic and may have been taken when their vertical migrations impinged on the slope. INTRODUCTION The fauna of the Southern Ocean is highly distinctive, with high levels of endemism in many faunal groups including ¢sh (Eastman & Grande, 1989) and cephalo- pods (Filippova, 2002). However, much of our knowledge of the Southern Ocean fauna is restricted either to shallow water (diving and commercial trawling) or the pelagic zone, with scienti¢c nets. Few studies have inves- tigated deeper areas, and those that have typically used small nets. In the South Georgia region of the Scotia Sea the marine ecosystem is characterized by high biomass and productivity of both phytoplankton and zooplankton (Atkinson et al., 2001). The region also supports large populations of seabirds and marine mammals, and commercial ¢sheries for tooth¢sh ( Dissostichus eleginoides Smitt, 1898), ice¢sh ( Champsocephalus gunnari Lo« nnberg, 1905) and krill ( Euphausia superba Dana, 1850). Whilst the neritic ¢sh and cephalopods have been described in some detail, the deeper fauna has been overlooked, and with ¢shing activity extending into deep water it is important to establish the faunal composition. In January 2003 a deep-water trawl survey was under- taken around South Georgia, focused on tooth¢sh and species that are taken asby-catch in that ¢shery, but here we describe the cephalopods that were caught during the cruise. MATERIALS AND METHODS The bottom trawl survey, undertaken in January 2003, included 44 trawl stations (Figure 1; Table 1) organized in ten transects. Each transect comprised ¢ve stations at depths of approximately 100, 300, 500, 700 and 900 m, however, rough ground meant that not all stations could be completed. A commercial sized demersal trawl (FP^120) was towed for 30 min at each station. The headline height averaged 6.1m, with a wing spread of  20 m. Mesh size ranged from 160 mm in the upper wings to 40 mm in the cod-end liner. Trawling was restricted to daylight hours. Catches were sorted immediately after capture. Squid were identi¢ed from published guides, and octopods with reference to recent literature (e.g. Daly & Rodhouse, 1994; Yau et al., 2002).Total length (TL), mantle length (ML) and wet weight (using a motion compensated balance (Pols)) were measured immediately. Sex was determined where possible. Specimens that could not be readily iden- ti¢ed were ¢xed in 10% bu¡ered formalin, preserved in 70% ethanol and returned to the British Antarctic Survey laboratory at King Edward Point, South Georgia for detailed examination. Stomachs were dissected from two of the more abundant squid species ( Moroteuthis knipovitchi Filippova, 1972 and Psychroteuthis glacialis Thiele, 1920) and were frozen for later analysis. Stomach contents were subsequently identi¢ed using a dissecting microscope, using reference material and published guides (Reid, 1996). RESULTS During the cruise 193 cephalopod specimens were collected comprising six species of octopod and seven of squid. Depth ranges of capture and sizes of captured specimens of these species are detailed inTable 2. The most abundant octopods were of the species Adelieledone polymorpha (Robson, 1930), 60 specimens were captured. This species appears also to be the most diverse spatially, being captured at 16 stations (Table 1). Pareledone turqueti (Joubin, 1905) was also abundant, with 38 speci- mens captured at 12 stations. Interestingly, P. turqueti was also captured around Shag Rocks (stations shown in bold, Table 1), whereas the distribution of A. polymorpha was restricted to the South Georgia shelf. Three other incirrate octopod species were captured from deeper waters but were less abundant. These comprised 25 specimens of the easily identi¢ed Thaumeledone gunteri Robson, 1930, two specimens of an undescribed Pareledone species, similar in J. Mar. Biol. Ass. U.K. (2004), 84, 415^419 Printed in the United Kingdom Journal of the Marine Biological Association of the United Kingdom (2004)