Tri-spine Horseshoe Crab

The tri-spine horseshoe crab, also called the Chinese or Japanese horseshoe crab, is found in coastal and brackish waters across Southeast and East Asia, with records from China, Indonesia, Japan, South Korea, Malaysia, the Philippines, Taiwan, and Vietnam. It is the largest living horseshoe crab species, with females reaching up to 79.5 centimeters in total length and males averaging around 54 centimeters, and takes its name from three small spiny processes on the rear section of its body. It tolerates colder water than other Asian horseshoe crabs, though its juveniles need water warmer than 22 degrees Celsius to molt successfully. The IUCN classified it as Endangered in 2019 because of overfishing, pollution, and habitat loss, with populations declining sharply across its range, particularly in Taiwan.