REPRODUCTION OF THE CALANOID COPEPOD CALANUS-PROPINQUUS IN THE SOUTHERN WEDDELL SEA, ANTARCTICA - OBSERVATIONS IN LABORATORY

Reproduction of the dominant Antarctic copepod Calanus propinquus was studied in February-April, 1989 aboard the R.V. 'Dmitry Mendeleev' dur ing cruise N-degree 43 to the Weddell Sea. Single females were kept at 0-degree-C in the laboratory for 56 days with abundant food concentra tion (above 300 mug C l-1 of Platymonas viridis). Females released clu tches at night at 2-3 day intervals. Most clutches contained from 10 t o 40 eggs, mean 37.3 eggs female-1. Average carbon content of an egg w as 0.37 +/- 0.05 mug C. The maximum daily egg production rate of 30-50 eggs female-1 d-1 was observed for the first 3 days of the laboratory incubation, corresponding to 3.7-6.2% body C. The state of gonadal de velopment of females showed the decline of the reproductive season in late February. The data suggest that egg laying in the region under st udy starts in December and lasts until March. The state of ovarian mat uration, changes in vertical distribution and biochemical body composi tion of females suggest the possibility of two-year life cycle in C. p ropinquus in the southern Weddell Sea.