PHYSIOLOGICAL-CHARACTERISTICS OF THE ANTARCTIC COPEPOD CALANOIDES-ACUTUS DURING LATE SUMMER IN THE WEDDELL SEA

Ingestion, respiration and excretion rates as well as lipid and protei n body content of the dominant Antarctic copepod Calanoides acutus (CI V to adult females) were studied during the period covering the end of phytoplankton bloom (February) to the beginning of transition to over wintering (March-April). Daily rations measured with gut fluorescence varied from 2.2 to 2.7% in surface C. acutus. Weight-specific respirat ion and excretion rates in deep C. acutus decreased by a factor of 11 and 3.5-3.8 compared to their surface counterparts. High lipid (up to 455 mug ind-1) and protein (198 mug ind-1) content was observed in sur face C. acutus CV in February; a month later the animals with similar lipid and protein content were found in the depth (500-1000 m layer). Their lipid reserves were enough to overwinter and probably to ascend, molt and reproduce. At the same time some of the deep CVs had much lo wer protein and lipid content and could survive only for 4-5 months. O ur own and literature data led to the conclusion that females of C. ac utus reach adulthood at the age of more than one year while developmen t of males could be completed in one year.