Ecological studies of marsh crabs, Sesarma spp. II : Habitats, copulation and egg-bearing season

DOI IR (HANDLE) Web Site 2 Citations Open Access

Bibliographic Information

Other Title
  • ベンケイガニ類の生態II : 生息場所,交尾および抱卵期
  • 生息場所,交尾および抱卵期
  • セイソク バショ , コウビ オヨビ ホウランキ

Search this article

Description

Sesarmid crabs were widely found from the vicinity of the house standing along the river side to the estuary. The crabs living at the vicinity of the house were limited to S. (H.) haematocheir, S. (H.) dehaani and S. (S.) intermedium. From the observation of these crabs, their habitats, mating habits and other reproductive status were cleared in the present paper as follows: 1) The authors reported on the habitats of 5 species of sesarmid crabs, S. (H.) haematocheir, S. (H.) dehaani, S. (S.) intermedium, S. (P.) erythrodactylum and S. (P.) pictum, and also on the correlation between the nest hole and crabs found in the active or hibernating period. 2) By the survey of the distribution at a small river, following three types of distribution were all owed. a. S. (H.) haematocheir, S. (H.) dehaani and S. (S.) intermedium distributed up to the upper region of the river where was not effected by the sea water, but the population density of S. (S.) intermedium declined to the low density in this small river. b. It seemed that S. (P.) erythrodactylum and S. (P.) plicatum distributed only in the brackish water and were not found in the fresh or sea water region. c. Contrary to the crabs, such as S. (H.) haematocheir and S. (H.) dehaani, S. (P.) pictum inhabited the comparatively high salinity region at the sea shore throughout the year. 3) Observing the ecdysis of S. (H.) haematocheir, they proved the time from the beginning to the end of exuviation and the growth after the molting. 4) The pairing of sesarmid crabs continued from the middle of May to that of July. Though the male individual paired with the female by day and by night, the frequency of mating was higher at night than at daytime. 5) The mating habit of sesarmid crabs seemed to be similar to that of the other grapsoid crabs, but the male crab took the place below the female when the mating was disturbed by other animals. 6) It was proved by the periodic collection of the crabs that the sesarmids crabs carried their eggs on the abdominal appendages from the end of May to that of September but this period varied according to species and the size of ovigerous crabs differed from individual to individual.

Journal

Citations (2)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top