Spermatogenesis and physiological maturity of male red king crab (Paralithodes camtschaticus Tilesius, 1815) and snow crab (Chionoecetes opilio Fabricius, 1788) in the Barents Sea

Abstract

Spermatogenesis and physiological maturity in the Barents Sea red king crab and snow crab were studied using histological methods. Samples of the red king crab and snow crab were collected between 1994–2000 and 2004–2008, respectively. The development of the germ cells in red king crab and snow crab testes is accompanied by the formation of spermatophores, which indicate physiological maturity. The smallest red king crabs with spermatophores were of 65 mm carapace length (CL). Spermatophores were found in 95% of 70–79 mm CL crabs and in all specimens with CL exceeding 80 mm. Spermatogenesis in red king crab males occupies approximately two years and is season-dependent. The Barents Sea snow crabs reach physiological maturity at 43 mm carapace width (CW). In the samples analysed, all males with CW exceeding 45 mm contained spermatophores. Unlike the red king crab, the production of ripe germ cells in the snow crab is continuous rather than associated with a definite season. Physiologically mature but morphometrically immature male red king crabs and snow crabs are unlikely to participate in the mating.