The first investigation record of threatened horseshoe crabs in the Banyuasin estuarine, South Sumatra, Indonesia

Abstract

The first investigation of the Asian horseshoe crabs in the Banyuasin Estuarine (Indonesia) was carried out during July 16-31, 2019. Sampling was conducted together with local fishermen using a trammel net. Two species of the Asian horseshoe crabs have been identified from 52 obtained specimens, namely Carcinoscorpius rotundicauda (♂ = 18, ♀ = 27) and Tachypleus gigas (♂ = 5, ♀ = 6). The prosoma width for the two species was 100-150 mm and 115-210 mm respectively, with body weights of 72- 285 grams and 99- 918 grams, respectively. All specimens of C. rotundicauda were adults (their prosomal width ≥ 8 cm). Female was larger in size than male for both species. Its geographical distribution was from the waters near mangroves up to 4.2 km towards the sea. These results indicated that Banyuasin Waters was included in the geographical distribution coverage for both species. Further studies were needed to assess population structure, abundance, spawning ground, spawning activity, growth aspects as well as morphometric and DNA studies.