Reproductive potential of southern king crab (Lithodes santolla) in South Patagonian Sector (south 48°S), a new fishery area

Abstract

In December 2016, a new area for Lithodes santolla fishery was authorized in the South Patagonian Sector (SPS), Argentina. This is the first study of the southern king crab reproductive potential in this area. Reproductivepotential was assessed by determining female size at sexual maturity and describing population size distribution and sex ratio. Moreover, size-fecundity relationships and egg quality were analyzed including potential spatialdifferences with the Central Patagonian Sector (CPS). The size distribution of L. santolla showed differences between the sexes, females were significantly smaller than males. Female average size was 80mm CL and 114mm CL for males. The sex ratio showed a clear predominance of males and was 9.6: 1 with respect tofemales. The female size at maturity was 65mm CL. Fecundity ranged between 2,963 and 15,730 eggs for 63-96mm CL females. This parameter presented a positive relationship with female size and was significantly higher than values obtained for CPS. Eggs average diameter ranged from 1,516 to 1,764 μm. This variable didnot show a significant relationship with female size and was lower than that recorded for the CPS. Egg dry weight showed a positive relationship with female size and was significantly higher than those sampled in the CPS. These results provide critical data that may be used in stock assessment models to establish a base line to evaluate the effects of fishing and environmental changes on reproductive potential.