Reproductive-Biology of the False Southern King Crab (Paralomis-Granulosa, Lithodidae)in the Beagle Channel, Argentina

GUSTAVO ALEJANDRO LOVRICH; VINUESA, JH

FISHERY BULLETIN

NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE

Año: 1993 vol. 91 p. 664 - 675

0090-0656

Reproduction of thefalse southern king crab (Paralomisgranulosa.) in two localities of theBeagle Channel. Argentina. wasstudied by monthly trap samplingduring 1989 and 1990. Size at gonadalmaturity in males (50.2-mmcephalothoracic length. CLl and females(60.6-mm CLl was significantlyless than size at morphometricmaturity (57.0-mm CL in males;66.5-mm CL in femalesl. Embryonicdevelopment lasted 18-22 months.During this period. there was apparentlya 10-12 month diapause. Inone of the two localities, developmentof eggs in a given clutch wasvery heterogeneous. suggesting simultaneousoccurrence of eggs with12- and 22-month development periods.Larval hatching took placemainly during winter. Female P.granulosa. molted during Novemberand mated immediately after. Biennialreproduction was detected onthe basis of ovarian and embryonicdevelopment, and on the basis ofshell condition. Thus. two differentfemale groups occur in the populationof the Beagle Channel. Fecundityincreases with size (1,441 to8.110 eggs per female) and is significantlyless at the end than at thestart of embryogenesis. Ovaries andbrood each represented at most 67%ofbody weight. Paralomis gramllosais the only representative of itsgenus that inhabits shallow waterand apparently retains some reproductivefeatures of its deepwaterrelatives.