Summer distribution and abundance of juvenile Chinese horseshoe crabs Tachypleus tridentatus along an intertidal zone in southern China

Owing to human exploitation, pollution and loss of breeding and nursery grounds, Chinese horseshoe crabs Tachypleus tridentatus are facing the risk of population decline and even- tual extinction. In order to provide baseline information needed to formulate future conservation strategies, we examined the spatial distribution, densities and carapace width of juvenile T. tridenta- tus along 6 transects at an intertidal zone of Beibu Gulf, South China Sea, during the summer of 2008. The environmental parameters measured (water temperature, salinity and dissolved oxygen) did not vary significantly among transects. However, the abundance and size distribution of juvenile T. tri- dentatus was statistically different between transects. Juvenile T. tridentatus prefer to move further from their natal area as they grow: therefore, smaller juveniles tend to be distributed closer to the shore, while larger juveniles are located further offshore.

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