On two new species of deep-sea carrier crabs (Crustacea, Brachyura, Homolodromiidae, Dicranodromia) from Taiwan and the Philippines, with notes on other Indo-West Pacific species

Abstract

The systematics of four species of the homolodromiid genus Dicranodromia A. Milne-Edwards, 1880, from East Asia and the Philippines is reappraised: D. danielae Ng & McLay, 2005, D. doederleini Ortmann, 1892, D. karubar Guinot, 1993, and D. martini Guinot, 1995; and key characters such as the epistome, gonopods, and spermatheca are figured in detail. Two new species, D. erinaceussp. nov. and D. robustasp. nov., are described from Taiwan and the Philippines, respectively. Dicranodromia erinaceussp. nov. resembles D. spinulata Guinot, 1995, and D. delli Ahyong, 2008 (from New Caledonia and New Zealand) but can be separated by its distinctly spinulated carapace surfaces and proportionately shorter fifth ambulatory legs. Dicranodromia robustasp. nov. is superficially similar to D. baffini (Alcock & Anderson, 1899) and D. karubar Guinot, 1993, but can easily be separated by possessing a broad dorsoventrally flattened infraorbital tooth. A genetic study of the species using the mitochondrial cytochrome c oxidase I gene confirms that the taxa are distinct, with D. erinaceussp. nov. coming out in a well-supported clade from congeners. The megalopa of D. doederleini is also reported for the first time.