Abstract:

This paper presents the results of net sampling carried out on two marine cruises during the austral summer of 1989/1990 and 1990/1991 in the Prydz Bay region (Indian Ocean sector of the Southern Ocean) by the Chinese R/V "Jidi".The sexual maturity stages of totally 8243 specimens of Antarctic krill(Euphausia superba Dana) were examined. The spawning season begins in January and extends to March with the maximum spawning occurring in mid-or late-February,about one month later compared with the Atlantic sector.The L/F distribution of gravid females (3DF) shows that the spawning popualtion mainly consists of two age groups:3 + and 4 +. The 3 + adults are the main spawners with the 4 + adults partly contributing.2 + and 5 + seems to be very scare in the spawning population if any.Among the 5916 specimens determinable sex only 34.1% are males. The percentage of males decreases with the increasing of body size.It drops to 22.9% when the body length exceeds 50 mm.