Zoological Studies

Vol. 46 No. 3, 2007

Some Reproductive Aspects of Gecarcoidea lalandii (Brachyura: Gecarcinidae) in Taiwan

Hung-Chang Liu1 and Ming-Shiou Jeng2,*

1Department of Ecology, Providence University, Shalu, Taichung County, 433 Taiwan.   E-mail:hcliu@pu.edu.tw
2Research Center for Biodiversity, Academia Sinica, Nankang, Taipei 115, Taiwan

Hung-Chang Liu and Ming-Shiou Jeng (2007) sThe reproductive biology of the land crab Gecarcoidea lalandii was documented on the Hengchun Peninsula, southern Taiwan.  Ovigerous females have an average carapace width of 57 7 (range, 42-78) mm (n = 287).  The breeding season is variable, depending on the beginning of the rainy season, and in 2003, it lasted from June to Oct., a relatively longer breeding season than determined for its congener, G. natalis.  Ovigerous females usually release their larvae during 7-10 d in the last quarter of the lunar cycle.  Larval release shows a closer relationship with the timing of sunrise than with the high tide.  This species exhibits an unusual larval release behavior while clinging to vertical rock faces in which the ovigerous females drop egg masses into the water without actually entering the water.  This unusual larval release from above the water and the choice of surge channels as release sites are thought to be adaptations to life on land which may reduce the risks of mortality to ovigerous females.

Key words: Gecarcoidea, Gecarcinidae, Larval release, Reproduction.

*Correspondence: Tel: 886-2-27899514 or 27899577. Fax: 886-2-27858059.  E-mail:jengms@gate.sinica.edu.tw