Growth and reproduction of the two-spot swimming crab Charybdis bimaculata (Miers, 1886) (Decapoda, Brachyura) in Goheung Bay, Korea.

The growth and reproduction of Charybdis bimaculata (Miers, 1886) were investigated in Goheung Bay, Korea, from February 2020 to February 2021. Females were observed more frequently than males. The gonadosomatic index varied monthly, and reached the highest value in July. Ovigerous females peaked in July as well. The main spawning season was summer. The size at sexual maturity of females, corresponding to a proportion of 0.5 sexually mature individuals, was estimated as 20.93 mm carapace width (CW). The relationship between ln number of eggs (EN) and ln CW was ln EN = 1.59 ln CW + 4.92 for noneyed eggs, and ln EN = 1.91 ln CW + 6.11 for eyed eggs. Males grew faster than females ( L ∞ = 43.65 mm CW and K = 0.95 year−1 for males, and L ∞ = 43.65 mm CW and K = 0.8 year−1 for females). [ABSTRACT FROM AUTHOR]