First inventory of the Crustacea (Decapoda, Stomatopoda) of Juan de Nova Island with ecological observations and comparison with nearby islands in the Mozambique channel (Europa, Glorieuses, Mayotte)

• Decapoda and Stomatopoda of Juan de Nova inventoried for the first time (112 species).
• Species richness is one of the lowest within Islands of the Mozambique Channel.
• Low species richness at Juan de Nova related to small size of the Island as well as to uneasy sampling on outer reef flat.
• Endangered Coconut crab (Birgus latro) is protected at Juan de Nova and sporadically finds refuge in this island.

Crustacea Decapoda and Stomatopoda are inventoried for the first time in Juan de Nova Island, Iles Eparses, Mozambique channel. In total, 112 species are reported: 69 crabs, 28 anomurans, 11 shrimps, 3 mantis shrimps and 1 lobster. A comparison is made with nearby islands in the Mozambique channel: Glorieuses Islands (157 species), Europa Island (178 species), and Mayotte Island (505 species). The lower species richness at Juan de Nova is explained by the small size of the island and by the difficulties to collect the crustaceans on the reef flat hardly accessible at low tide. The crustaceans are listed by main habitats from land to outer reef (2–20 m). The presence of the coconut crab (Birgus latro), an endangered species vulnerable to human predation, is confirmed.