Seasonal variation in the intertidal distribution of the hermit crab Clibanarius rhabdodactylus Forest, 1953 on the rocky shores of Saurashtra coast, Gujarat, India

Abstract :

In the present study, the intertidal distribution of Clibanarius rhabdodactylus Forest, 1953 was studied in the rocky intertidal region of Veraval along the Saurashtra coast, Gujarat, India. Monthly sampling was carried out from September 2020 to August 2021 using line transect method intercepted with quadrates (0.25 m2) from the upper intertidal mark to the lower intertidal mark for quantification of C. rhabdodactylus. Similar transect method intercepted with quadrates (1 m2) was employed to quantify coverage of microhabitat. Individuals of C. rhabdodactylus from each quadrate were collected in zip-lock bags using hand-picking method. In the laboratory, shield length (SL) of each individual of C. rhabdodactylus was measured and classified as male, non-ovigerous female or ovigerous female. The monthly data of abundance was compiled for different seasons, viz., winter (November to February), summer (March to June) and monsoon (July to October). The abundance of C. rhabdodactylus varied significantly between seasons with maximum values recorded in winter followed by summer and monsoon. In case of microhabitat, upper intertidal zone was maximally composed of tide pools while middle and lower intertidal zone was maximally composed of open area. Tide pool water temperature and ambient temperature varied significantly between seasons. Overall abundance data showed that the species mostly preferred the upper intertidal region and the presence of higher number of tide pools in the upper intertidal zone might be the possible reason behind the confinement of C. rhabdodactylus in the upper intertidal region.

Keyword :

Anomuran crab, intertidal region, microhabitat preference, rocky coast, spatio-temporal variation, tidepool

Author(s) : Patel, K., Vachhrajani, K., Trivedi, J.
Downloads : 15
Published Issue : 2023 Vol. 18 Number 1

2023 Vol. 18 Number 1