REPRODUCTIVE-BIOLOGY OF THE FALSE SOUTHERN KING CRAB (PARALOMIS-GRANULOSA, LITHODIDAE) IN THE BEAGLE CHANNEL, ARGENTINA

Reproduction of the false southern king crab (Paralomis granulosa) in two localities of the Beagle Channel, Argentina, was studied by monthl y trap sampling during 1989 and 1990. Size at gonadal maturity in male s (50.2-mm cephalothoracic length, CL) and females (60.6-mm CL) was si gnificantly less than size at morphometric maturity (57.0-mm CL in mal es; 66.5-mm CL in females). Embryonic development lasted 18-22 months. During this period, there was apparently a 10-12 month diapause. In o ne of the two localities, development of eggs in a given clutch was ve ry heterogeneous, suggesting simultaneous occurrence of eggs with 12- and 22-month development periods. Larval hatching took place mainly du ring winter. Female P. granulosa molted during November and mated imme diately after. Biennial reproduction was detected on the basis of ovar ian and embryonic development, and on the basis of shell condition. Th us, two different female groups occur in the population of the Beagle Channel. Fecundity increases with size (1,441 to 8,110 eggs per female ) and is significantly less at the end than at the start of embryogene sis. Ovaries and brood each represented at most 67% of body weight. Pa ralomis granulosa is the only representative of its genus that inhabit s shallow water and apparently retains some reproductive features of i ts deepwater relatives.