Soviet Biological Exploration in Antarctic Seas

... The 11th Soviet Antarctic Expedition was the first in Soviet antarctic research to employ aqualungs in biological exploration. Such explorations were conducted from mid-December to March, during the antarctic summer 1966-67. The special methods we employed were determined by the peculiar nature of our hydrobiological research. Instead of exploring the expanses of the ocean bottom, as had been the practice of all foregoing expeditions, we confined our observations to a limited area of shallow sea between the Haswell Islands near the Mirny Observatory. Lightweight diving apparatus permitted us to observe animals in their natural environment, discover the nature of submarine communities, and collect specimens of the flora and fauna. All together, 144 dives were made. ... Three months' work yielded extensive collections which were brought to the Zoology Institute of the U.S.S.R. Academy of Sciences in Leningrad. However, the main significance of the expedition was the opportunity afforded to study the communities of animals and the regularities of their distribution throughout the sea depths. Few such observations have been made in Antarctica. ..

An Antarctic shelf population of the deep-sea, Pacific brachiopod Neorhynchia strebeli

Thirty-five specimens of the articulate brachiopod Neorhynchia strebeli were collected from a site at 814 m in the Weddell Sea. This was only the second species of the order Rhynchonellida to be found in Antarctica. Formerly N. strebeli was known solely from abyssal Pacific Ocean localities. A circumantarctic distribution is suggested in addition to the known deep-sea Pacific range. The specimens of this collection showed considerable commissure variation, suggesting that the previously proposed erection of two subspecies on the basis of this character is erroneous, and emphasises the phenotypic plasticity of some articulate brachiopods. The valve lengths and the number of alpha growth rings in the sample showed a normal distribution and a von Bertalanffy growth function was fitted to the data: Lt = 23 (1-exp[-0·228t]). If the alpha growth rings were of annual periodicity, the ages attained by the Antarctic N. strebeli of 11 y would be substantially lower than those reported for other Weddell Sea brachiopods. The epibiotic communities occurring on the valves of N. strebeli were impoverished, which is characteristic of deep water Antarctic brachiopods. The few specimens collected with their substratum were attached to small pebbles, but the typical attachment substrata may be different