The Biological Bulletin, Vol 186, Issue 3 300-308, Copyright © 1994 by Marine Biological Laboratory

ECOLOGY AND EVOLUTION

Laboratory Studies on Molting and Growth of the Shore Crab, Hemigrapsus sanguineus de Haan, Parasitized by a Rhizocephalan Barnacle

T. Takahashi and S. Matsuura
Department of Fisheries, Faculty of Agriculture, Kyushu University, Hakozaki, Fukuoka 812, Japan

Molting of shore crabs (Hemigrapsus sanguineus) parasitized by rhizocephalans (Sacculina senta) was observed in the laboratory, and the growth of the molted crabs was compared with that of unparasitized animals. Molting of the host was obstructed by the infestation, but was still possible. After the release of several broods of larvae, the externa (the external reproductive system of the parasite) detached from the host. Subsequent molting occurred within 40 days in about 80% of the animals, but in the remainder, it was delayed for at most 4 months. Soon after molting, a new externa protruded from the abdomen of every crab. Thus, the life-span of the externa and the molting of the host would seem to be closely connected. In the female, the molt frequency was reduced, but the molt increment of the parasitized crabs was not different from that in the unparasitized ones. In the male, however, both the molt frequency and the molt increment were reduced. Thus, the annual growth of parasitized males and females was about half that of unparasitized crabs.

This article has been cited by other articles:

				EPIBIONT PRESERVATIONAL AND OBSERVATIONAL BIAS IN FOSSIL MARINE DECAPODS Journal of Paleontology, September 1, 2004; 78(5): 961 - 972.