Limule

Les limules sont des arthropodes marins de la famille des Limulidae, connus pour leur carapace en forme de fer à cheval et leur longue queue en épine.

Limules are marine arthropods of the family Limulidae, known for their horseshoe-shaped carapace and long spine-like tail. They live primarily in shallow coastal waters and are not crustaceans but chelicerates related to spiders and scorpions. The term may also refer to the genus *Limulus*, whose best-known species is *Limulus polyphemus*.

Classification

Limules form the family Limulidae within the chelicerate arthropods. They are classified in the order Xiphosura and should not be confused with crabs, which are crustaceans.

Morphology

Limules possess a horseshoe-shaped carapace, multiple eyes, and a rigid tail called a telson. They have appendages adapted for movement and feeding on the sea floor.

Habitat and distribution

These animals live in shallow coastal waters, often near beaches, estuaries, and the intertidal zone. Their presence is reported on the Atlantic coasts of North America and in parts of Asia.

Biological and medical importance

Limule blood is used to detect certain bacterial endotoxins in biomedical contexts. This use has contributed to the scientific notoriety of the animal.

Conservation

Several limule populations face pressures from fishing, collection, and modification of coastal habitats. Their conservation status varies by species and region.