Morphological and molecular systematics of swimming crabs (Decapoda: Brachyura: Portunidae) from India collected on-board the FORV Sagar Sampada (cruise no. 378, 385 and 392), with notes on biogeography of the Indian portunid fauna

Morphological and molecular characters of swimming crabs (Family Portunidae Rafinesque-Schmaltz, 1815) collected during one cruise each of the Fishery Oceanographic Research Vessel Sagar Sampada in the northeastern Arabian Sea (97–110 m depth), southwestern Bay of Bengal (56 m), and southeastern Bay of Bengal (56 m) and western Andaman Sea (53 m) were studied. They are referred to as 17 species representing 4 subfamilies, 8 genera, and 2 subgenera. Cycloachelous levigatus Koch, 2021, Monomia rubromarginata (Lanchester, 1900), Thalamita malaccensis Gordon, 1938 are the first records from Indian waters. The study also reveals variations in the pleonal and genital morphology of Monomia argentata (A Milne Edwards, 1861) form B (sensu Stephenson and Rees, 1967a). Mitochondrial Cytochrome oxidase subunit I and 16S rRNA gene sequences of 14 and 16 species, respectively revealed a monophyletic subfamily Lupocyclinae Alcock, 1899, and polyphyletic subfamilies Portuninae Rafinesque, 1815 and Thalamitinae Paulson, 1875.