Feeding Ecology and Dietary Preferences of Tachypleus gigas from East Malay Peninsula

Horseshoe crabs forage on locally available prey and spawn every month in shallow coastal areas. To investigate their feeding compositions and preferences, monthly sampling between March 2010 and February 2011 was carried out during the lunar tide. Tachypleus gigas adults were either handpicked on shore or captured using gill nets, and their size-weight indices were measured. In general, remnants of bivalve, gastropod, crustacean, and polychaete were identified in the gastrointestinal tract of T. gigas. This arthropod foraged primarily on mollusks (bivalves and gastropods) along the Pahang coast with larger gut contents during non-monsoon (i.e., peak spawning) season in May to August. Furthermore, T. gigas were found to feed mainly on bivalves during the non-monsoon, but on polychaete during the monsoon seasons. Male crabs consumed more than female crabs. Food source availability influenced T. gigas’s monthly diets rather than the presumed opinion on dietary preferences from hatchery-based feeding assays. Data produced in this study can be a baseline regarding T. gigas feeding regimes during transitional weather and can be a guide for captive culture of horseshoe crabs.