First record of the three-spined box crab, Arcania undecimspinosa De Haan, 1841 (Decapoda, Brachyura, Leucosiidae) from the Arabian Sea, with a key to the species of Arcania recorded from the Indian coast

A single specimen of the three-spined box crab, Arcania undecimspinosa De Haan, 1841, measuring 21.0 mm CW and 20.5 mm CL, is here documented for the first time from the Arabian Sea along the north-west coast of India. Previously, the species has been only reported from the Bay of Bengal region along the Indian coast. The present study provides a detailed taxonomic description of the species with high-resolution colour photographs and line drawings, along with a key to the species of the genus Arcania known from the Indian coast.