The Paralithodes camtschatica are dioecious, meaning separate sexes, and have external fertilization. Because of they are aquatic therefore they are able to transfer sperm outside the body without risk of the sperm to dry out, so that external fertilization is possible for this species.Owing to the females crabs are polygynous, they can only mating once a year.

Once female Paralithodes camtschatica attracting the male Paralithodes camtschatica by pheromones after their eggs are hatched, the reproduction cycle of the red king crab begins. First the male should find the female, then he need to attach to her and use his claws to grasping her into a face-to-face position. They stay connected until the female molts her carapace and creates new eggs. He will spread his spermatophores over her pleopods by his fifth pair of legs as soon as the female is in her soft-shell state (mating can occur only in this condition).

After mating, the eggs are been released immediately. The female can also store the sperm if the eggs are not ready to be released yet. Afterwards, the male holds in a spongy mass between the female’s abdominal flap and body, on her pleopods. Fecundity of the females varies between 15 000 to nearly 500 000 eggs, depending on area (Jewett and Onuf 1988). Female Paralithodes camtschatica brood eggs underneath their tail flap for about 11 months, keeping them healthy by waving water over them and making protective shelter from predators.

The cycle begins again once the eggs are hatched.

  1. Jewett, S.C. & Onuf, C.P. 1988. Habitat suitability index models: Red king crab. U.S. Fish & Wildl. Ser. Biol. Rep., National Wetlands Research Center, Slidell. Louisiana, 82 (10.153), 34 p.



Fig.6.Female Paralithodes camtschatica brood eggs underneath their tail flap. From:

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