Horseshoe crabs are marine and brackish water arthropods of the family Limulidae, and the only living members of the order Xiphosura.[2] Their popular name is a misnomer, as they are not true crabs, nor even crustaceans, as crabs are, but a different order of arthropod.
Horseshoe crabs live primarily in and around shallow coastal waters on soft, sandy or muddy bottoms. They tend to spawn in the intertidal zone at spring high tides.[3] They are commonly eaten in Asia, and used as fishing bait, in fertilizer and in science (especially Limulus amebocyte lysate). In recent years, population declines have occurred as a consequence of coastal habitat destruction and overharvesting.[2] Tetrodotoxin may be present in one horseshoe crab species, Carcinoscorpius rotundicauda.[4]
Fossil records for horseshoe crabs extend back as far as 240 million years ago, with extant forms being living fossils.[5] A 2019 molecular analysis places them as the sister group of Ricinulei within Arachnida.[6]
Horseshoe Crab has been suggested to play 12 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.
