Red Hermit Crab

Pagurixus ruber is a small marine hermit crab belonging to the family Paguridae, first described by Komai & Osawa in 2006. It is part of the Arthropoda phylum, Malacostraca class, and Decapoda order. These hermit crabs are typically found in tropical and subtropical waters of the Indo-Pacific region, including specific locations such as Réunion Island.

With a size of about 1.5 cm (0.6 inches), Pagurixus ruber is characterized by its distinctive red chelipeds and red legs adorned with white bands. It primarily inhabits coastal zones, often occupying empty shells of molluscs like Clanculus margaritarius to protect its soft abdomen. This species is benthic, meaning it lives on the sea floor, at depths ranging from the surface down to 20 meters (65 feet). Pagurixus ruber is more active at night, frequently found on reefs during these hours.

The species exhibits gonochorism, meaning individuals are distinctly male or female. Their mating involves a precopulatory courtship ritual, which employs olfactory (smell) and tactile (touch) cues, leading to a usually indirect sperm transfer.

Despite being of scientific interest, Pagurixus ruber holds no commercial value. However, it contributes to marine biodiversity, often captured in photographs showing them residing in shells on coral reefs.