Reproductive Biology of the Red Frog Crab, Ranina ranina (Linnaeus, 1758) (Crustacea: Decapoda: Raninidae) from Southwestern Mindanao, Philippines

The red frog crab (Ranina ranina (Linnaeus, 1758), Ranididae) is an important fishery resource in the Philippines and may have potential for aquaculture and stock enhancement. To determine basic reproductive information for the species in the Philippines, a one-year study was conducted of the red frog crab from southwestern Mindanao, Philippines. In both sexes, gonad activity occurred throughout the year but for females the peak egg bearing season was November to February (59-87% ovigerous). Body sizes of ovigerous females were from 61.9 - 148.2 mm carapace length (CL). The greatest prevalence of ovigerous females was in the size range of 90–99 mm CL; the lowest at 140–149 mm CL. Male crabs with mature testes were consistently high (83-100%) in all months of the year. Females had higher gonadosomatic indices (GSI), 4.90–26.64, compared to those of the males which were 1.77–5.36. Gonad indices (GI) varied from 1.77-2.9 for females and from 1.83 to 2.0 for males. The smallest female carrying eggs was 61.9 mm CL and the smallest male with a mature gonad was 40.23 mm CL. The number of eggs (fecundity) per egg mass ranged from 26,225-354,084 eggs individual^ -1.