Frecuencia e incremento por muda de la langostilla Munida subrugosa (Anomura: Galatheidae) en el Canal Beagle, Argentina.

TAPELLA, F.; LOVRICH, G.A.; ROMERO, M.C.

San Andrés, Colombia

Congreso; IX Congreso Latinoamericano de Ciencias del Mar; 2001

Four species of Galatheidae crabs occur in the Southern Atlantic. Munida subrugosa is the most abundant decapod crustacean. Particularly in the Beagle Channel, M. subrugosa may have a commercial interest. The objective of this study was resolve the frequency and increment per molt, in order to identify basic growth parameters of M. subrugosa. From January 1998 to February 2001, we took monthly samples with an ephibentic trawl. Molt frequency was determined by two ways: 1) estimating the proportion of animals >11 mm CL with soft exoskeletons, and 2) a monthly survey for molt stages (according to the exopodite tip of the 2nd maxilliped; O´Halloran y O´Dor, 1988) method. Moreover, we kept animals in captivity to record their molt increments. Munida subrugosa molt twice per year: during October-November after the reproductive cycle and during February-March. During the latter period, the molt increment was lesser. In specimens of both sexes <11 mm CL the molt increment increased with the size. At 11 mm CL (maturity gonadal size) a change in the growth rate of both sexes was recorded. The growth rate of mature males was smaller than immature males. The molt increment of females was negatively correlated with size.