Community Structure of Mud Crabs (Scylla spp.) from Buntal Mangroves,Kuching, Sarawak, Malaysian Borneo

Mud crabs (Scylla spp.) are commercially important species in Buntal Mangroves, Kuching, Sarawak, harvested mainly to meet the demand from local seafood restaurants. Fishermen have claimed that the size of mud crabs has declined, but no scientific study has been carried out to verify the statement. Therefore, a study was carried out to determine mud crab species composition and current community structure. Between February 2019 and January 2020, a total of 244 mud crabs were caught in Buntal Mangroves using collapsible baited crab traps. Their carapace length (CL), carapace width (CW) and wet body weight (BW) were measured. Four species of mud crab were collected, namely Scylla serrata, S. paramamosain, S. tranquebarica and S.olivacea. The sex ratios of S. olivacea and S. paramamosain were male biased; however, no sexual dimorphism was observed across all species in this study. The largest but rarest species caught during this study was S. serrata. It is hoped that more research work could be done in future to support sustainable utilisation of the resource and benefit the local communities

Effects of water parameters on population structure of mud crab from Buntal Mangroves, Kuching, Sarawak, Malaysia: A GLM analysis

Buntal Mangroves, Kuching, Sarawak, Malaysia, is an area that is abundant with biological resources but contains minimal biodiversity information. Mud crab fisheries by the locals exist on small scales at Buntal Mangroves, but there is a tendency to overfish due to the increasing demand for this resource. The relationship between the population structure of mud crabs and the environmental factors in Buntal Mangroves has not been explored. Therefore, this study aimed to apply the generalized linear models (GLM) for analyzing the population structure of mud crabs with selected water parameters in Buntal Mangroves. Scylla olivacea (Herbst, 1796) has the highest abundance in Buntal compared to S. tranquebarica (Fabricius, 1798) and other types of mud crab. Three GLM with carapace length, carapace width, and body weight as dependent variables were constructed. These GLMs with gamma-distributed response variables indicated that depth, pH, salinity, and turbidity positively affected body weight, carapace width, and carapace length, while temperature had a negative impact on the dependent variables. The results emphasized the importance of adopting the GLM to describe a relationship where the response variable followed a non-normal distribution. The findings provide a basis for future studies at Buntal Mangroves, not only for conservation purposes but also to support the utilization of this valuable resource sustainably