Polar Biol (1996) 16: 345—352 ( Springer-Verlag 1996 ORIGINAL PAPER B.I. Sirenko · E.L. Markhaseva · G.N. Buzhinskaya A.A. Golikov · T.V. Menshutkina · V.V. Petryashov T.N. Semenova · S.D. Stepanjants · S.V. Vassilenko Preliminary data on suprabenthic invertebrates collected during the RV Polarstern cruise in the Laptev Sea Received: 8 March 1995/Accepted: 7 September 1995 Abstract For the first time the invertebrate fauna of the near-bottom layers of the Laptev Sea (Siberian Arctic) was studied by means of a specially designed device — the benthopelagic sampler that was attached to an Agassiz trawl. Cnidarians, annelids, mollusks and arth- ropods were identified to species level and comprised 139 species in total. Fifty-one species are registered in the Laptev Sea for the first time and seventeen species are the first records for the Arctic Basin. Species are characterized as pelagic, benthic and suprabenthic (benthopelagic, nektobenthic, epibenthic) species. Introduction The marine animals living in the near-bottom layers are associated with benthic and pelagic communities (Wishner 1980). According to their mode of life, these taxa are considered as benthopelagic, nektobenthic or epibenthic (Wishner 1980; Petryashov 1990). Problems in efficiency of sampling the near-bottom fauna have led to the development of special gears (Holme 1964; Wishner 1980; Grice and Hulsemann 1970; Grice 1972; Roe and Darlington 1985; Rudyakov and Zaikin 1990). The ecology and taxonomy of benthopelagic animals have been intensively studied recently (Gowing and Wishner 1992; Heinrich et al. 1993) but data on the Arctic near-bottom fauna are still very rare. During the German-Russian expedition to the Laptev Sea B.I. Sirenko · E.L. Markhaseva ( ) · G.N. Buzhinskaya · A.A. Golikov · T.V. Menshutkina · V.V. Petryashov · S.D. Stepanjants · S.V. Vassilenko Zoological Institute, Russian Acad. Sci., Universitetskaya Naberezhnaya, 1, 199034 St. Petersburg, Russia T.N. Semenova P.P. Shirshov Institute of Oceanology, Russian Acad. Sci., Krasikova, 123, 117218, Moscow, Russia (Fu¨ tterer 1994) benthopelagic sampling was carried out on board RV Polarstern. Taxonomic examination of samples (except Foraminifera, Actiniaria, Hirudinea, Ostracoda, and partly Copepoda and Pisces) allows to provide an account of the near-bottom fauna of a high- latitude Arctic sea for the first time. Materials and methods The qualitative material was collected by Dr. Boris Sirenko on board RV Polarstern in 1993 in the Laptev Sea. Sampling was performed by a sampling system developed and used for the first time during the cruise: this system was named a benthopelagic sampler (BS). The BS was attached to the frame of an Agassiz trawl (Fig. 1). It consists of a rectangular metal frame (25]95 cm) with mounting device and attached sac (1.5 m in length). Its external and internal parts are a net of 3—4 mm and of 0.4-mm mesh size respec- tively. The metallic frame is attached with bolts and wire to the upper part of the Agassiz trawl. The distal part of the net is attached to the upper net of the Agassiz trawl to prevent the turning inside out of the bag when the trawl is being lowered. The lower part of the BS frame is kept 70 cm above the sea bed to prohibit catching sea bottom material. The small size of the BS frame in comparison with the frame of the Agassiz trawl (1.0]3.0 m) makes it very likely that the BS does not affect the catching ability of the Agassiz trawl. Such construction is convenient because it does not take any additional time at the station to perform suprabenthic tows. Ten samples were collected by BS in the depth range 51—3042 m (Table 1). The collected animals were carefully washed into cans on the deck of the ship and then preserved in 4% formaldehyde and removed to 70% alcohol in the laboratory. Unfortunately the last sample (stn. 072) was contaminated by benthic animals during washing after the end of sampling. Taxa from this sample were therefore not taken into consideration: Mysidacea, Pseudomma roseum Sars 1870; Tanaidacea, ¸eptognathia sarsi Hansen 1913; Cumacea, Diastylis goodsiri (Bell 1855); Amphipoda, Gammaridea, Photis aff. reinhardi Krøyer 1842; Pleustidae gen. sp. juv.; Stegocephalus inflatus Krøyer 1842. A complete list of higher taxa collected during the cruise is given in Table 2. Results Cnidarians, polychaetes, copepods, mysids and gam- marids were the most abundant taxa in the samples.