The Physiological Ecology of Horseshoe Crabs (Tachypleus Tridentatus and Carcinoscorpius Rotundicauda) in Hong Kong

Horseshoe crabs are marine living fossils with four extant species, including Limulus polyphemus, Tachypleus gigas, T. tridentatus, and Carcinoscorpius rotundicauda. The last two species are found in Hong Kong. In view of the rapidly declining populations, this proposed study will investigate how the two principal environmental factors, temperature and salinity, and food availability affect the energy balance of juvenile T. tridentatus and C. rotundicauda in laboratory. The energy balance of field populations of two horseshoe crab species coexisting at two sites will also be studied each season for a year. The results may help better understand the optimum conditions for growth and survival of horseshoe crabs in laboratory conditions as well as their energy acquisition and expenditure in the wild. Information obtained will serve the basis for developing long term conservation strategy for these animals in Hong Kong.