The crabs in each sampling unit were collected by digging the sampling are at to the water table until they are caught and picking them by hand. The number of crabs that belong to different species were recorded and indentified up to species level using the taxonomic keys of Tirmizi et al. 1986
Soil samples were collected from each sampling plot and the environmental parameters, namely soil moister content, soil temperature soil salinity, soil pH and soil organic carbon content were measured. The soil moister content was measured by oven drying a know weight of a soil sample at 105 C to a constant weight. Soil temperature was measured by inserting a glass mercury thermometer into the soil after making a hole with a wire and soil salinity was measured by a salinity refractometer (A TAGO model) and soil pH was measured using a portable soil pH meter (Hach-Sension model). Water required for salinity measurements were collected by squeezing soil samples through a syringe. Soilorganic carbon content was measured following the method described by Walkly and Black 1934
Data were analyzed statistically using complete Random Block design (CRBD) of the SAS statistical package. Correlations between environmental parameter and crab abundance were analyzed using regression analysis in Excel Data Analysis tool. Shannon – weiner diversity index (H’) was calculated using the following given in Zar 1995