GASTROPOD SHELL OCCUPATION PATTERN OF HERMIT CRAB Clibanarius rhabdodactylus FOREST, 1953 IN THE INFRALITTORAL ZONE OF GULF OF KACHCHH, GUJARAT, INDIA

The gastropod shell occupation pattern by Clibanarius rhabdodactylus Forest, 1953 was studied in the infralittoral zone of the Jakhau fishing harbor, Gujarat, India. Specimens of C. rhabdodactylus were collected from muddy bottom at the depth of 10 meters using a fishing boat equipped with trawl net. Hermit crabs were categorized into male, non-ovigerous female and ovigerous female and their shield length and wet weight were recorded. Gastropod shells species were identified and morphological variables such as shell length, shell aperture length and width, shell dry weight and shell volume were recorded. Total 2000 individuals of C. rhabdodactylus were collected (976 males, 957 non-ovigerous females and 67 ovigerous females) occupying 36 different species of gastropod shells. Shells of Indothais lacera (51.35%), Babylonia spirata (16.60%), Cerithideopsilla cingulata (8.25%), Tibia insulaechorab (4.15%), and Cantharus spiralis (4.0%) were highly occupied. Ovigerous females were significantly larger in shield length than non-ovigerous females and males. Regression analysis showed relationship between the shield length and wet weight of C. rhabdodactylus and morphological variables such as shell length (SHL), shell aperture length (SAL), shell aperture length (SAW), shell dry weight (DW) and shell volume (SHV) of gastropod shells. Highest values of relationship were obtained between morphological parameters of C. rhabdodactylus and SAL, SAW and SHV. The results showed that shell morphology has pronounced impact on the shell occupation pattern of C. rhabdodactylus.