Polar Biol (2009) 32:963–970 DOI 10.1007/s00300-009-0595-4 ORIGINAL PAPER Records of the gadoid Wsh Arctogadus glacialis (Peters, 1874) in the European Arctic Michaela Aschan · Oleg V. Karamushko · Ingvar Byrkjedal · Rupert Wienerroither · Igor V. Borkin · Jørgen S. Christiansen Received: 10 December 2008 / Revised: 21 January 2009 / Accepted: 6 February 2009 / Published online: 12 March 2009  Springer-Verlag 2009 Abstract The Arctogadus glacialis is endemic to the Arctic Ocean and its apparently disjunct circumpolar distribution range from the Siberian coast through the Chukchi Sea and the Canadian Arctic to the shelf oV NE Greenland. Records of A. glacialis are scarce in the European Arctic and here we present all available and reliable records of the species in the area. Altogether, 296 specimens of A. glacialis are reported from 53 positions in the European Arctic during the period 1976–2008. The specimens were registered oV Iceland and the Jan Mayen Island, northwest and northeast of Svalbard, northeast in the Barents Sea, and south and east oV Franz Josef Land. The additional records show that A. glacialis display a circumpolar and more continuous distribution than described before. In the European Arctic, A. glacialis has been caught at 155–741 m depth with the highest abundance at 300–400 m. We therefore suggest that A. glacialis is more associated to the continental shelves surrounding the Arctic Ocean than previously M. Aschan (&) · J. S. Christiansen Norwegian College of Fishery Science, University of Tromsø, 9037 Tromsø, Norway e-mail: michaela.aschan@uit.no O. V. Karamushko Murmansk Marine Biological Institute, 183010 Murmansk, Russia I. Byrkjedal Bergen Museum, University of Bergen, 5020 Bergen, Norway R. Wienerroither Institute of Marine Research, 5817 Bergen, Norway I. V. Borkin Polar Research Institute of Marine Fisheries and Oceanography (PINRO), 183763 Murmansk, Russia thought. The length–weight relation of A. glacialis is similar across the European Arctic. Keywords Island Arctogadus · Gadidae · Arctic · Jan Mayen Introduction The gadoid Arctogadus glacialis (Peters, 1874) is one of the few Wsh species endemic to the Arctic Ocean (Andriyashev 1964), and recently it has caught special attention as a putative indicator for climate change (ACIA 2005; Schiermeier 2007). The species has been reported from both ice-free and ice-covered waters in the Canadian Arctic and Siberian Sea and seldom south of the Arctic Circle (Svetovidov 1948; Nielsen and Jensen 1967; Frost 1981; Dorrien et al. 1991; Süfke et al. 1998). An apparent disjunct circumpolar distribution of Arctogadus glacialis range from the Siberian coast through the Chukchi Sea and the Canadian Arctic to the shelf oV NE Greenland (Fig. 1a) (Nielsen and Jensen 1967; Boulva 1970, 1972, 1979; Christiansen 2003). The species has not been reported in the European Arctic until recently oV Iceland (Jónsson and Pálsson 2006), east of Svalbard (Byrkjedal et al. 2001), and south and east of Franz Josef Land (Borkin and Mel’yantsev 1984; Borkin et al. 2008). Previously, the genus Arctogadus was considered to encompass two valid species, i.e. A. glacialis (Peters, 1874) and A. borisovi Dryagin, 1932, based on diVerences thought to exist in, e.g. barbel length, interorbital width and horizontal diameter of the eye (Andriyashev 1964; Nielsen and Jensen 1967; Boulva 1972). Phylo-genetic studies by Møller et al. (2002) and a re-evaluation of morphometric data by Jordan et al. (2003), however, conclude that A. borisovi should be 123 964 Polar Biol (2009) 32:963–970 (a) Siberian Sea Atlantic Ocean (b) Fig. 1 a Catches of Arctogadus glacialis previously registered by Boulva (1979) and based on Nielsen and Jensen (1967) with corrections done for the observations along the Russian and Siberian coast. We here separate between original registration as A. glacialis (white square) and registration as A. borisovi (black square) in the Arctic region before 1980 (Drjagin 1932; Popov 1933; Svetovidov 1948; Andriyashev 1964; Nielsen and Jensen 1967; Andriyashev et al. 1980; Süfke et al. 1998; Christiansen 2003; Jordan et al. 2003; Christiansen 2005; Køie et al. 2008). One symbol may represent more than one haul and more than one specimen. b Positions where veriWed Arctogadus glacialis (Table 1) has been observed in the European Arctic, 1–4 individuals (white), 5–20 individuals (grey) and >20 individuals (black) considered a junior synonym of A. glacialis (Peters, 1874) as suggested by Walters (1955). The synonymization, thus, expands the habitat of A. glacialis to coastal and even brackish waters (Andriyashev 1964; Jordan et al. 2003). We present all available and reliable records of A. glacialis in the European Arctic, including the central North Atlantic (60°N; 20°W), the Northeast Atlantic (82°N; 80°E), and the Barents and Kara Seas. We compile the less accessible literature that exists presently on Arctogadus records and report new records, which are not previously published. The geographical distribution area of A. glacialis is revised and expanded considerably. In addition, the spatial habitat as well as the basic growth relationships of the species across the European Arctic are shown and discussed. 123 Materials and methods Study area The area studied covers the Barents and Kara Seas as well as the shelf areas around Iceland, Jan Mayen Island, Svalbard and Franz Josef Land. We here name this expanded Northeast Atlantic as the European Arctic (Fig. 1b). Polar Biol (2009) 32:963–970 Sampling The database on A. glacialis (Table 1) is based mainly on Wsh and shrimp surveys carried out by the Marine Research Institute (MRI), Iceland, the Polar Research Institute of Marine Fisheries and Oceanography (PINRO), Russia, the Institute of Marine Research (IMR), Norway, and the Norwegian Institute of Fisheries and Aquaculture (NIFA, now NoWma), Norway. The MRI has conducted spring surveys since 1985 and autumn surveys since 1996. PINRO conducted nine surveys in the Kara Sea between 1960 and 1997, and again two surveys in the Kara Sea in August– September 2007. IMR and NIFA have conducted surveys in the Barents Sea and the Svalbard area in late winter, in spring, in summer, and early autumn since 1982 (Aschan and Sunnanå 1997). Since 2004, IMR has conducted annual ecosystem surveys in the same area focussing also on noncommercial species. Occasional surveys in the waters of Jan Mayen Island have been conducted by the University of Tromsø (Christiansen 2008; Nilssen and Aschan 2008). We have also included one German record from Svalbard 1976 (Anon 2000; Froese and Pauly 2007). The majority of surveys with A. glacialis were conducted by the R/V “Jan Mayen”. A Campelen 1800 shrimp trawl with a 20 mm inner net (Aschan and Sunnanå 1997) was employed in both the Norwegian and the Russian surveys. The 1995 survey in the Jan Mayen area was conducted by M/T “Remøy” and Wve of 42 stations (nos. 35, 36, 38, 40, 41) were sampled with a commercial Egersund 2800 shrimp trawl. During surveys, Wsh were taxonomically identiWed, counted, and measured by species. Proper identiWcation of non-target species in the Weld, however, may be dubious and A. glacialis might have been mistaken for the abundant gadoid Boreogadus saida (Byrkjedal et al. 2001). Therefore, any questionable record has been excluded from the database and the specimens presented here are all taxonomically veriWed to A. glacialis. The species identiWcation was occasionally conducted on board the survey vessel, but in most cases, the specimens where frozen and later analysed in the laboratory. The A. glacialis were identiWed from the following combination of characters; eye diameter equal to or larger than the snout, body scales imbricated, strong palatine teeth, and lateral line straight behind middle of second dorsal Wn (Svetovidov 1986; Jordan et al. 2003). Data treatment All records and corresponding information are kept in a database. The spatial distribution of A. glacialis was studied by presenting the relative abundance in 100 m depth intervals. The total length (TL, cm) and body weight (BW, g) was registered for most specimens oV Svalbard and 965 Franz Josef Land, while size data are available only for the two specimens caught oV Jan Mayen in 2008 and one specimen caught oV Iceland in 1995. The TL–BW relations of log-transformed data were compared to those from a main distribution area of A. glacialis in NE Greenland (Dove Bugt and Tyrolerfjord) (Christiansen 2003). Results Altogether, 296 specimens of A. glacialis are reported from 53 positions during the period 1976–2008 (Table 1). New records of A. glacialis were registered oV Iceland and the Jan Mayen Island, northwest and northeast of Svalbard, northeast in the Barents Sea, and south and east oV Franz Josef Land (Fig. 1b). The largest known specimen, 52 cm and 1.2 kg, was sampled oV Iceland 10 January 1995 by a commercial Wshing vessel. Three other Icelandic specimens were found in 1995, 1999, and 2001 (Jónsson and Pálsson 2006). The Icelandic specimens ranged in TL 24–52 cm, and the southernmost veriWed observation of A. glacialis was recorded at 64°47⬘N oV the southeast coast of Iceland. The species has not been reported within the Faroese 200 nm Wshery zone (Rógvi Mouritsen, personal communication). Apart from the main distribution oV Greenland, the Canadian Arctic and the Siberian Sea, A. glacialis appears to be the most abundant in the waters of Jan Mayen Island, where a total of 206 specimens were registered at 12 stations (Table 1). The highest number (137) of individuals at one station was caught by the Egersund 2800 shrimp trawl. At another station, also sampled in 1995, the 22 individuals caught varied between 15 and 29 cm. Bottom temperatures varied between ¡0.6 and 1°C in 1995. A ripe female (TL = 37 cm) with ovulating eggs was caught oV Jan Mayen in July 2008 (Christiansen 2008). A total of 33 A. glacialis were caught at 25 stations north and east of Svalbard in 1976 and during 1997–2008 (Table 1). One of the specimens was caught southeast of Svalbard in the Barents Sea. The Wrst individual (ZMH 115085, TL = 43 cm) was sampled west of Svalbard in a survey with R/V “Anton Dohrn” in 1976 (Anon 2000). Only single specimens are registered at most stations. The TL varied between 12 and 28 cm. Temperature data at four stations oV Svalbard varied between 0.4 and 2.7°C. In 1980, two A. glacialis were found just south of Franz Josef Land (Borkin and Mel’yantsev 1984). In September 2007, 43 A. glacialis were sampled at 7 stations south and east of Franz Josef Land in the northern part of the Kara Sea at near bottom temperatures from –0.6 to 0.34°C (Borkin et al. 2008). The largest catch (34 specimens) was recorded at 79°00⬘N, 65°14⬘E at 369–374 m depth. The Wsh were 12–26 cm in TL (mean TL »15 cm) and had an 123 966 123 Table 1 List of stations in the Northeast Atlantic where Arctogadus glacialis has been recorded Year Date Inst. Station no. Latitude Longitude Area Depth (m) 1995 10 Jan MRI CFV 64°50⬘N 11°38⬘W Iceland 275 1995 11 Nov MRI CFV 66°34⬘N 25°12⬘W Iceland 450 1999 13 Mar MRI TB1-99-88 64°47⬘N 11°43⬘W Iceland 2001 12 Aug MRI D8-01-441 66°59⬘N 24°15⬘W Iceland 1995 19 Aug NIFA 24 71°00⬘N 7°45⬘W 1995 20 Aug NIFA 25 71°03⬘N 1995 20 Aug NIFA 30 1995 21 Aug NIFA 1995 21 Aug NIFA 1995 21 Aug 1995 n Reference Voucher specimens 1 Jónsson and Pálsson (2006) No 1 Jónsson and Pálsson (2006) HAF-1995-56 278 1 Jónsson and Pálsson (2006) HAF-1999-17 471 1 Jónsson and Pálsson (2006) No Jan Mayen 430 3 Aschan (1995) No 8°47⬘W Jan Mayen 444 2 Aschan (1995) TSZP 1972-1 71°06⬘N 9°26⬘W Jan Mayen 155 22 Aschan (1995) TSZP 1972-2 32 71°04⬘N 9°33⬘W Jan Mayen 470 11 Aschan (1995) No 35 70°24⬘N 8°19⬘W Jan Mayen 310 137 NIFA 36 70°36⬘N 10°15⬘W Jan Mayen 400 3 Aschan (1995) No 21 Aug NIFA 38 70°38⬘N 12°01⬘W Jan Mayen 257 15 1995 23 Aug NIFA 40 71°24⬘N 7°36⬘W Jan Mayen 680 2 1995 24 Aug NIFA 41 70°49⬘N 6°14⬘W Jan Mayen 440 6 1999 13 Sep NIFA 797 71°04⬘N 9°05⬘W Jan Mayen 460 1 No No No Aschan (1995) No No 1999 17 Sep NIFA 846 70°47⬘N 9°11⬘W Jan Mayen 167 2 2008 2 Jul UiT 226 70°37⬘N 8°26⬘W Jan Mayen 192 2 Christiansen (2008) No nr. yet No 1976 6 Aug ISH 2393 78°44⬘N 8°54⬘E Svalbard 460 1 Anon (2000) ZMH 115085 1997 6 Aug NIFA 698 80°17⬘N 11°04⬘E Svalbard 300 1 1998 18 Aug NIFA 724 80°11⬘N 10°47⬘E Svalbard 348 2 1998 10 Sep IMR 75 79°09⬘N 32°38⬘E Svalbard 364 1 1999 18 Aug NIFA 692 80°29⬘N 12°55⬘E Svalbard 592 1 1999 18 Aug NIFA 697 80°44⬘N 14°19⬘E Svalbard 350 1 2000 20 Feb IMR 108 74°34⬘N 33°35⬘E Svalbarda 242 1 Byrkjedal et al. (2001) ZMUB 10894 2000 2 Sep IMR 840 81°21⬘N 22°49⬘E Svalbard 364 1 Byrkjedal et al. (2001) ZMUB 11359 2000 9 Sep IMR 876 79°34⬘N 28°59⬘E Svalbard 325 1 Byrkjedal et al. (2001) ZMUB 11360 2001 31 Aug NIFA 18 80°37⬘N 15°37⬘E Svalbard 315 1 ZMUB 11529 2002 9 Aug NIFA ser. 81306 79°53⬘N 8°15⬘E Svalbard 595 1 No 2002 10 Aug NIFA ser. 81704 80°12⬘N 10°04⬘E Svalbard 578 2 No 2002 27 Aug NIFA ser. 81723 80°22⬘N 11°20⬘E Svalbard 286 1 No 2002 28 Aug NIFA ser. 81713 80°46⬘N 14°33⬘E Svalbard 433 1 No No No No Byrkjedal et al. (2001) ZMUB 10805 No No 30 Aug NIFA ser. 81750 81°22⬘N 22°54⬘E Svalbard 373 1 2003 3 Sep IMR ser. 81404 80°22⬘N 8°19⬘E Svalbard 727 1 ZMUB 19731 2004 18 Sep IMR ser. 2170 81°37⬘N 33°52⬘E Svalbard 389 1 No 2006 14 Sep IMR ser. 2098 79°48⬘N 7°59⬘E Svalbard 624 1 HIFIRE F 4432 Polar Biol (2009) 32:963–970 2002 Year Date Inst. Station no. Latitude Longitude Area Depth (m) n Reference Voucher specimens 2007 12 Sep IMR ser. 2025 78°59⬘N 9°52⬘E Svalbard 239 1 2007 21 Sep IMR ser. 2096 81°15⬘N 26°23⬘E Svalbard 430 1 ZMUB 19560 2007 21 Sep IMR ser. 2098 81°28⬘N 29°58⬘E Svalbard 579 1 V-158/07 2007 22 Sep IMR ser. 2107 81°02⬘N 29°49⬘E Svalbard 178 3 ZMUB 19619 2007 22 Sep IMR ser. 2109 81°41⬘N 29°01⬘E Svalbard 551 2 ZMUB 19776 2007 23 Sep IMR ser. 2115 81°11⬘N 29°39⬘E Svalbard 300 4 ZMUB 19652 HIFIRE F 4431 2008 13 Sep IMR ser. 2041 80°30⬘N 11°36⬘E Svalbard 741 1 ZMUB 19764 2008 13 Sep IMR ser. 2046 80°42⬘N 13°48⬘E Svalbard 489 1 ZMUB 19765 ZMUB 19775 1980 31 Aug PINRO 168 79°30⬘N 60°37⬘E Franz Josef Land 320 1 Borkin and Mel’yantsev (1984) No 1980 1 Sep PINRO 179 79°49⬘N 60°37⬘E Franz Josef Land 275 1 Borkin and Mel’yantsev (1984) No 2007 15 Sep PINRO 6 79°00⬘N 65°14⬘W Franz Josef Land 374 34 Borkin et al. (2008) No 2007 15 Sep PINRO 7 79°00⬘N 67°38⬘E Franz Josef Land 428 2 Borkin et al. (2008) No 2007 15 Sep PINRO 8 79°43⬘N 66°35⬘E Franz Josef Land 500 1 Borkin et al. (2008) No 2007 16 Sep PINRO 9 80°32⬘N 66°59⬘E Franz Josef Land 490 2 Borkin et al. (2008) No 2007 16 Sep PINRO 10 81°15⬘N 68°13⬘E Franz Josef Land 578 2 Borkin et al. (2008) No 2007 18 Sep PINRO 16 78°49⬘N 74°03⬘E Franz Josef Land 390 1 Borkin et al. (2008) No 2007 18 Sep PINRO 20 78°05⬘N 68°08⬘E Franz Josef Land 417 1 Borkin et al. (2008) No 2007 1 Sep PINRO 102 80°43⬘N 40°04⬘E Franz Josef Land 327 6 No 2007 17 Sep PINRO 143 78°56⬘N 51°21⬘E Franz Josef Land 301 1 No Polar Biol (2009) 32:963–970 Table 1 continued Date, institution in charge of survey; MRI The Marine Research Institute, Reykjavik, Iceland; NIFA The Norwegian Institute of Fisheries and Aquaculture; IMR The Institute of Marine Research,UiT The University of Tromsø, all Norwegian; PINRO The Knipovich Polar Research Institute of Marine Fisheries and Oceanography in Murmansk, Russia; ISH The Institut fur SeeWscherei, Hamburg, Germany. Station numbers given at survey, locations (latitude, longitude), area, mean depth of trawl haul, number of individuals (n) and code for voucher specimens are also given a Specimen found in the Barents Sea but treated with individuals found oV Svalbard 967 123 968 Polar Biol (2009) 32:963–970 1-100 1,000 201-300 301-400 401-500 501-600 601-700 701-800 801-900 0 20 40 60 80 Body weight (g) Depth interval (m) 101-200 100 10 Relative number of indidviduals (%) Jan Mayen Svalbard Franz Josef Land Greenland Fig. 2 Relative number of Arctogaus glacialis registered by depth interval in the European Arctic. N = 296 1 estimated age of 2–6 years. Immature Wsh (TL »14–16 cm, 74%) dominated the catch; however, the gonads of two females (TL »25–26 cm) were ripening. In addition, PINRO recorded two stations with A. glacialis east and west of Franz Josef Land. Six specimens were recorded at the latter station towards Svalbard. In the European Arctic, the overall depth distribution of A. glacialis ranges from 155 to 741 m with the number of observations being most abundant at depths of 300–400 m (Fig. 2). A comparison of the TL–BW relationship of A. glacialis across diVerent parts of the European Arctic revealed no geographical diVerences in growth performance (Fig. 3) and the common regression line could be described by the equation: BW = 0.0038 TL3.1754. Discussion About 40 years ago, Nielsen and Jensen (1967) stated that one would expect Arctogadus to have a circumpolar distribution and consequently occur oV Svalbard and Franz Josef Land. However, no observations had been made in the European Arctic at the time. Our study supplements the previously deWned distribution with veriWed observations oV Iceland and Jan Mayen Island, north and east of Svalbard, and south and east of Franz Josef Land. The recent records of A. glacialis across the European Arctic reveal a circumpolar and more continuous distribution, and this corroborates the suggestion of Nielsen and Jensen (1967). The A. glacialis has been categorized as cryopelagic, i.e. to be basically a pelagic species associated with sea-ice biota for at least part of its lifecycle (Andriyashev 1970). Based on data from the northeast water polynia in NE Greenland Süfke et al. (1998), on the other hand, concluded that A. glacialis has a broad variety in diet composition indicating an opportunistic pelagic feeding pattern. Copepods 123 8 16 32 64 Total length (cm) Fig. 3 Total length (TL) and body weight (BW) for Arctogadus glacialis oV Jan Mayen (two individuals from Jan Mayen and one from Iceland), Svalbard and Frans Josef Land presented with data from two fjords of NE Greenlandic, Dove Bugt and Tyrolerfjord, BW = 0.0055·TL3.0285(grey line), R2 = 0.99, N = 82 (Joensen personal communication). The common length–weight function for the European Arctic A. glacialis is BW = 0.0038 TL3.1754 (black line), R2 = 0.97, N = 66 dominated the diet of small Wsh at shallow stations whereas amphipods and mysids were more important for larger Wsh (>16 cm) and dominated catches in deeper waters. This corroborates well with the more benthic behaviour of A. glacialis (formerly A. borisovi) along the Siberian coast (Andriyashev 1964; Nielsen and Jensen 1967). In the European Arctic, A. glacialis has been caught by demersal trawls at 155–741 m depth with the highest abundance at 300–400 m (Fig. 2). Although a higher sampling eVort in the shelf areas than in deep water (>700 m) may aVect these records, we suggest that A. glacialis is more associated to the continental shelves surrounding the Arctic Ocean than previously thought (Andriyashev 1957; Walters 1961). This contrasts the abundant and widespread Boreogadus saida, which is associated to pelagic waters and the sea-ice (Lønne and Gulliksen 1989). Furthermore, B. saida may even occur beneath the sea-ice in the deep basins of the Arctic Ocean. The A. glacialis is considered a high Arctic species and is usually found in water masses ranging ¡0.6 to 1.5°C (Nielsen and Jensen 1967). This corresponds to our Wndings north of Svalbard and south of Franz Josef Land where most of the Wsh were caught at ¡0.7 and 1.4°C. Yet, at two stations (north of and northwest of Svalbard) the temperature was above 2.5°C, and two specimens from southwest Greenland were caught in water of about 3.4°C with boreal fauna characteristics (Nielsen and Jensen 1967). This Polar Biol (2009) 32:963–970 indicates that A. glacialis is not physiologically limited to Arctic waters. There is strong evidence that A. glacialis spawns in winter (Andriyashev 1964; Andriyashev et al. 1980; Süfke et al. 1998), as is also known for B. saida (Hognestad 1968). However, Rass (1948) assumed that spawning takes place in the summer in warmer coastal waters which was supported by Wndings of fry (26–41 mm) in bottom trawl hauls in October in the East Siberian Sea (Andriyashev 1964). Attention to the ecology of the Arctogadus was given in the last review of the genus (Jordan et al. 2003). In this review, earlier records of mature Arctogadus caught in summer, previously described as A. borisovi, with ripe ovaries are mentioned (Andriyashev 1964; Coad et al. 1995; Jordan et al. 2001). The occurrence of a ripe female at Jan Mayen (Christiansen 2008) supports the possibility of summer spawning in Arctogadus. The TL–BW relations of A. glacialis are similar across the European Arctic (including the selected fjords of NE Greenland) (Fig. 3). Length at age relations of A. glacialis from the Canadian Arctic by Boulva (1979) suggests that the specimens oV Iceland are all older than 6 years with the largest specimen (52 cm) being older than 11 years. However, most of the recorded specimens are <30 cm and <7 years as shown by Borkin et al. (2008) in the Kara Sea. In conclusion, the occurrence of immature, mature, and even ripe specimens indicates that the natural habitat of A. glacialis is linked to the shelf areas throughout the Arctic Ocean and that the species reproduce also in the European Arctic. Acknowledgments We thank the crew onboard R/V “Jan Mayen” and the other vessels that provided material. We also thank Robert Bergersen, Tromsø Museum, University of Tromsø, for searching the collections. Jónbjörn Palson, Marine Research Institute, Reykjavik, Iceland and Rógvi Mouritsen, the Faroese Fisheries Laboratory, Tórshavn, Faroe Islands kindly searched national data for Arctogadus registrations. Special thanks to Frøydis Strand, University of Tromsø, who helped us with the maps. Part of the material was obtained from the TUNU-MAFIG Programme, University of Tromsø. We are thankful for constructive advice from three referees. References ACIA (2005) Arctic climate impact assessment. Cambridge University Press, Cambridge Andriyashev AP (1957) A new species in the fauna of the USSR belonging to the cod family, Arctogadus glacialis (Peters), from the drifting station “Severnyy polyus-6”. Zool Zh 36:1747– 1749 Andriyashev AP (1964) Fishes of the Northern seas of the U.S.S.R. In: Pavlovskii EN (ed) Keys to the fauna of the U.S.S.R. Israel Programme ScientiWc Translation, Jerusalem, p 566 Andriyashev AP (1970) Cryopelagic Wshes of Arctic and Antarctic and their signiWcance in polar ecosystems. In: Holdgate MW (ed) Antarctic ecology. Academic Press, New York, pp 297–304 969 Andriyashev AP, Mukhomediyarov BF, Pavshtiks EA (1980) On mass accumulation of cryopelagic codWshes (Boreogadus saida and Arctogadus glacialis) close to pole areas of the Arctic. In: Shirshov PP (ed) Biology of the Central Arctic basin. Nauka, Moscow, pp 196–211 Anon (2000) Fish collection database of the Intitut fur SeeWscherei (ISH). BIOLAB Forschungsinstitut, Hohenwestedt, Germany Aschan M (1995) Kartlegging av rekebestanden i Jan Mayen-området (Mapping the shrimp stock in the Jan Mayen area). Fiskeriforskning, Rapport: 21. 27 pp Aschan M, Sunnanå K (1997) Evaluation of the Norwegian shrimp surveys conducted in the Barents Sea and the Svalbard area 1980– 1997. ICES, CM 1997/Y 7:1–24 Borkin IV, Mel’yantsev RV (1984) New data on the distribution of polar cod, Arctogadus glacialis (Gadidae), in the Arctic region. J Ichthyol 24:101–103 Borkin IV, Vasil’ev AV, Chetirkina OY (2008) Ikhtiofauna (Ichthyofauna) The Ecosystem of the Kara Sea, Murmansk, pp 130–206 Boulva J (1970) The systematics of sympatric populations of the Arctic codWshes, Arctogadus borisovi Djagin and A. glacialis (Peters), from Cambridge Bay, N.W.T. Canada. Master of Science, Halifax Boulva J (1972) Morphometrics of three sympatric Arctic codWshes on the genera Arctogadus and Gadus. J Fish Res Board Can 29:243–249 Boulva J (1979) Comparison of the Arctic cod (Boreogadus saida), the polar cod (Arctogadus glacialis) and the toothed cod (Arctogadus borisovi). Quebec, 79/50, pp 12 Byrkjedal I, Langhelle G, Lemvig S (2001) Arctic cod Arctogadus glacialis (Peters, 1874), recorded east of Svalbard. Funn av istorsk Arctogadus glacialis (Peters, 1874) øst for Svalbard. Fauna 54:10–13 Christiansen JS (2003) TUNU-I Expedition. The Wsh fauna of the NE Greenland fjord systems, Danmarkshavn (77°N)–Eskimonæs (74°N), 2–16 October 2003. Norwegian College of Fishery Science, University of Tromsø, pp 31 Christiansen JS (2005) TUNU-II Expedition. Marine Wshes of NE Greenland—diversity and adaptation (TUNU-MAFIG), Gael Hamke Bugt (74°N)–Kap Brewster (70°N), 26 September–10 October 2003. Norwegian College of Fishery Science, University of Tromsø, pp 28 Christiansen JS (2008) TUNU-Seal 2008, Marine Fishes, Seals and other Creatures. Marine biological investigations at Jan Mayen Island and in Vestisen, 29 June–12 July. Norwegian College of Fishery Science, University of Tromsø, pp 27 Coad B, Waszczuk H, Labignan I (1995) Encyclopedia of Canadian Wshes. Canadian Museum of Nature and Canadian SportWshing Production Inc, Ottawa Dorrien CF, Piepenburg D, Schmid MK (1991) On the abundance of Arctic cod Arctogadus glacialis in Northeast water. Polar Rec (Gr Brit) 27:362–364 Drjagin PA (1932) Arctogadus eine neue Gaidengattung aus Nordostsibirien. Zool Anz 98:151–154 Froese R, Pauly D (2007) FishBase. World Wide Web electronic publication, www.fishbase.org Frost KJ (1981) Descriptive key to the otholiths of gadid Wshes of the Bering, Chukchi and Beaufort seas. Arctic 34:55–59 Hognestad P (1968) Observations on polar cod in the Barents Sea. Rapp P-V Reun-Cons Int Explor Mer 158:126–130 Jónsson G, Pálsson J (2006) Íslenskir Wskar (Fishes of Iceland). VakaHelgafell, Reykjavik Jordan AD, Jungersen M, SteVensen JF (2001) Oxygen consumption of East Siberian cod: no support for the metabolic cold adaptation theory. J Fish Biol 59:818–823. doi:10.1111/j.1095-8649.2001. tb00152.x Jordan AD, Møller PR, Nielsen JG (2003) Revision of the Arctic cod genus Arctogadus. J Fish Biol 62:1339–1352. doi:10.1046/ j.1095-8649.2003.00115.x 123 970 Køie M, SteVensen JF, Møller PR, Christiansen JS (2008) The parasite fauna of Arctogadus glacialis (Peters) (Gadidae) from western and eastern Greenland. Polar Biol 31:1017–1021. doi:10.1007/ s00300-008-0440-1 Lønne OJ, Gulliksen B (1989) Size, age and diet of Polar cod, Boreogadus saida (Lepechin 1773), in ice covered waters. Polar Biol 9:187– 191. doi:10.1007/BF00297174 Møller PR, Jordan AD, Gravlund P, SteVensen JF (2002) Phylogenetic position of the cryopelagic codWsh genus Arctogadus Drjagin, 1932 based on partial mitochondrial cytochrome b sequences. Polar Biol 25:342–349. doi:10.1007/s00300-001-0348-5 Nielsen JG, Jensen JM (1967) Revision of the Arctic cod genus, Arctogadus (Pisces, Gadidae). Medd Gronl 184:1–26 Nilssen E, Aschan M (2008) Catch-, survey- and life history of shrimp (Pandalus borealis) at Jan Mayen. Deep Sea Res (in press). doi:10.1016/j.dsr2.2008.11.013 Popov AM (1933) To the knowledge of the ichtyofauna of the Siberian Sea. Arctica 1:157–168 Rass TS (1948) Life stages and pattern of growth and development of Fishes. Izv Acad Nauk SSSR 3:295–305 123 Polar Biol (2009) 32:963–970 Schiermeier Q (2007) The new face of the Arctic. Nature 446:133– 135. doi:10.1038/446133a Süfke L, Piepenburg D, von Dorrien CF (1998) Body size, sex ratio and diet composition of Arctogadus glacialis (Peters, 1874) (Pisces: Gadidae) in the Northeast Water Polynya (Greenland). Polar Biol 20:357–363 Svetovidov AN (1948) Fishes 4: Gadiformes. In: Pavlovskii EN (ed) Keys to the fauna of the USSR. Israel Programme ScientiWc Translation (1962), Jerusalem, p 304 Svetovidov AN (1986) Gadidae. In: Whitehead PJP, Bauchot M-L, Hureau J-C, Nielsen JG, Tortonese E (eds) Fishes of the Northeastern Atlantic and Mediterranean. UNESCO, Paris, pp 680– 710 Walters V (1955) Fishes of the western Arctic America and Eastern Arctic Siberia, taxonomy and zoogeography. Bull Am Mus Nat Hist 106:255–368 Walters V (1961) Winter abundance of Arctogadus glacialis in Polar Basin. Copeia 2:236–237. doi:10.2307/1440013