• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.670-678
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• 2010

An ecological investigation was conducted in winter from November 2007 to February 2008, around Wangdol Reef in the East Sea to analyze the population structure and fecundity of Chinoecetes opilio. The sex ratio was 30.11:69.89% (female:male) in November, 62.03:37.97% in December, 37.59:62.41% in January and 14.69:85.31% in February. Regression equations indicated highly positive relationships between size and weight parameters (carapace length, width, total weight). During the sampling period ovigerous females were continuously collected. The percentage of ovigerous females was 96% in November, 90.57% in December 89.80% in January, and 88.46% in February. The average number of embryos was 64,800. The regression equation between carapace width and the number of embryos was y = 2.6805x - 0.9182 ($R^2$ = 0.7166). Embryo volume increased as embryo development proceeded. The mean size of an embryo was 0.72 mm. Embryo volume ranged from 0.42 to $0.84\;m^3$ during embryo developmental stages 1 to 3.

• Journal of Aquaculture
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• v.11 no.3
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• pp.337-344
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• 1998

This paper documented mophological changes of embryonic development and first zoea larvae of snow crab, Chinoecetes opilio. Female crabs were sampled by the Danish seine fishery at the depth about 200m in Sep. 1997 in the eastern coast of Korea. Female with newly berried eggs was reared at the water temperature of 5$^{\circ}C$ till the time of hatching. The results obtained are as follwos. Embryonic development : According to morphogenesis of fertilized eggs, the developemental process of the embryo was classified into the following seven stages : First stage (cleavage and blastula stage, 24 days) Second stage (gastrula stage, 72 days) Third stage (nauplius stage, 22 days) Fourth stage (metanauplius stage, 57days) Fifth stage (stage of a pigmentary deposit in the compound eye, 30 days) sixth stage (chromatophore appearance stage in maxillipede, 56 days) Seventh stage (hatching stage, 36 days) Larvae hatched as prezoeas and they molted to first zoea in about an hour. The first zoea is 4.6 to 5.1mm in length, 3.2~3.6mm in width. The abdomen consists of five segments and a bifurcate telson.