Size structure and sexual maturity of the golden crab (Chaceon chilensis) exploited off Robinson Crusoe Island, Chile
Golden crab (Chaceon chilensis) specimens were analyzed after being caught with traps by artisanal fishermen off Robinson Crusoe Island, Juan Fernández Archipelago, Chile. Of the 13,027 individuals caught between 300 and 1,000 m depth, 97.9% were male (12,754) and the rest female (273). The carapace length (CL) of the sampled crabs was measured and, on average, the males (CL: 118.9 mm) were larger than the females (CL: 94.3 mm). On the north side of the island, the specimens presented lower average sizes (112.2 mm) whereas, in the remaining zones, the average carapace lengths were similar (CL: 117.1-119.5 mm). In bathymetric terms, an increasing trend was seen between average size and depth, with sizes over 123 mm CL found beginning at 750 m depth. A comparison of linear regressions between the carapace length and chela length of males revealed physical maturity at 100 mm CL, whereas a numerical analysis showed the size at first sexual maturity (SSM50%) to be 109 mm CL.