NOTOTHENIOID FISHES FROM THE WEDDELL SEA AND THEIR HABITAT, OBSERVED BY UNDERWATER PHOTOGRAPHY AND TELEVISION (Twelfth Symposium on Polar Biology)

About 3000 photographs and 21 hours of video were used to analyze and describe the habitat and some peculiarities of the behavior of high Antarctic notothenioid fish. These direct observations were made during three cruises of the German research vessel "POLARSTERN" to the shelf of the Weddell Sea (ANT III, 1984/85; ANT VI, 1987/88; ANT VII, 1988/89). Operating depth of the vehicles was between 100 and 1200m. In total, 987 specimens of more than 20 fish species were identified. The total area observed at 98 stations was estimated as 3000m^2 for the photographs and 12300m^2 for the video. The most abundant species were Chionodraco myersi with 192 and Trematomus lepidorhinus with 159 specimens observed. They are followed by Trematomus scotti (103), Dolloidraco longedorsalis (56), Trematomus eulepidotus (51) and Prionodraco evansii (41). Most of the species found are known to be demersal. But also benthopelagic species like Trematomus eulepidotus, C. myersi or Neopagetopsis ionah (18) were found near or above the bottom. While the real demersal fish (e.g. Trematomus centronotus or Trematomus loennbergii) ware observed directly on the bottom, within or even on the benthic organisms, the video pictures show that benthopelagic species such as Trematomus eulepidotus or N. ionah swim some centimeters above the bottom. For some of the species a relation to the kind of substratum can be shown. Species composition depends on water depth and latitude