Description

The Warty Sea Spider Crab (Maguimithrax spinosissimus), also known as the Caribbean King Crab, is the largest species of spider crab on Caribbean reefs. The carapace of the largest identified male measured 17 cm long and 18.4 cm wide. Its rough, pear-shaped carapace is a deep red with yellowish hues. The term “warty” comes from the numerous tubercles and spines covering its carapace and its long, slender legs.

Diet :

Being nocturnal, this crab primarily forages at night. Omnivorous, scavenging, and detritivorous, it feeds mainly on algae such as sargassum, as well as carcasses and organic debris.

This species and its diet play a significant role in maintaining ecosystem balance: by consuming marine animal carcasses and by helping restore coral reefs through the consumption of algae. Additionally, the Mote Marine Laboratory in Florida is working to combat the effects of coral bleaching caused by algae overgrowth by training Caribbean king crabs to eat these harmful algae species.

Habitat

The species prefers tropical waters such as the Caribbean Sea and the Gulf of Mexico, with temperatures ranging from 20 to 28 °C. It is generally found at depths of 1 to 50 meters but can go down to 179 meters, inhabiting rocky and gravel areas as well as coral reefs. It also tends to camouflage itself among algae and marine debris. Generally solitary, this crab defends its territory against other crabs.

Threats

The main threats to this species are pollution, habitat destruction, and overfishing.

Furthermore, a 2013 study by the French Research Institute for Exploitation of the Sea (IFREMER) confirmed contamination of this species in Guadeloupe between 2008 and 2011 by chlordecone.

Sources

Le crabe royal des Caraïbes, le sauveur des récifs coralliens ? – Guadeloupe la 1ère (francetvinfo.fr)

Maguimithrax spinosissimus | DORIS (ffessm.fr)