Characteristics and density of the horseshoe crab (Tachypleus gigas) from gillnet fishery in Pamekasan, Madura Island

Abstract

Abstract The horseshoe crab is included in the category of protected species (ETP) because of its rare existence. Therefore, it is essential to identify the characteristics and density of horseshoe crabs. This study aimed to examine horseshoe crabs’ morphometric characteristics and density (Tachypleus gigas) on the coast of Polagan Village, Pamekasan Regency, Madura. This study was conducted from November to December 2020. Results showed that 45 horseshoe crabs were found in Pamekasan waters during the study period, consisting of 30 males and 15 females. The total average length was 164.57±40.92 mm and 163.67±31.30 mm for males and females, respectively. Males than females dominated horseshoe crabs. The density was based on the size class, consisting of 9 ind of small size (73-132 mm), 31 ind of medium size (133-222 mm), and 5 ind of large size (223-282mm). The water quality was classified as good for the growth of the horseshoe crab population, with sediments dominated by sand and silt. Further study is needed regarding the seasonal variation of horseshoe crab in Pamekasan Water.