Tachypleus gigas, commonly known as the Indo-Pacific horseshoe crab, Indonesian horseshoe crab, Indian horseshoe crab, or southern horseshoe crab, is one of the four extant (living) species of horseshoe crab. It is found in coastal water in South and Southeast Asia at depths to 40 m (130 ft).
Tachypleus gigas
Illustrations of male from above and below. Notice that the illustration from below incorrectly shows all walking legs as scissor-like, as in females (in males, the two frontal pairs of walking legs have hooks)
Male found dead in Bako National Park, Malaysia
Individual found dead on Indonesian shore
Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura. Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids such as spiders, ticks, and scorpions.
Horseshoe crab
Image: Tachypleus gigas
Image: Feart 08 00098 g 033
Underside of two horseshoe crabs showing the legs and book gills