The Coastal Horseshoe Crab, one of 4 species of Horseshoe Crabs in 3 genera, are not true crabs, nor even crustaceans,
but are closely related to arachnids (spiders, scorpions). The Coastal Horseshoe Crab is native to tropical coasts of South and Southeast Asia,
from the Bay of Bengal to the Philippines in salt and brakish water.
The larger females can grow to 25cm diameter and 50cm long including the tail. Unlike the Mangrove Horseshoe Crab which overlaps in range,
the Coastal has longer spikes on the body and a serrated tail. Females have 3 spikes on each side and the smaller males and juveniles have 6 spikes on
each side. They are vulnerable to over-harvesting and habitat loss. Their blue blood is used in medical science across the globe to rid vaccines of bacteria,
increasing the pressure on them.