Rhinobatos nudidorsalis Last, Compagno & Nakaya, 2004

Family:  Rhinobatidae (Guitarfishes)
Max. size:  50.1 cm TL (male/unsexed)
Environment:  demersal; marine; depth range - 125 m
Distribution:  Central Indian Ocean: Mascarene Ridge.
Diagnosis:  This species is distinguished by the following characters: no thorns on upper surface of the disc, with tail and unpaired fins almost entirely naked; a small, elongate to oval-shaped denticle patch across a naked upper caudal peduncle and upper caudal-fin lobe; a wedge-shaped disc; moderately large orbit, exceeding 4% total length (TL); oblique nostrils, length 1.7 times internarial distance; anterior nasal flaps penetrating well into internarial space, but not almost united; posterior nasal flaps broad; ridges of rostral cartilages well separated dorsally and almost parallel; prebranchial sensory pore patch narrow, extending to first gill slit; postscapular sensory canal long with lateral pores, not grooved, extending almost to pectoral-fin insertions; low dorsal fins; pelvic-fin inner margin distinctly longer than its base; interdorsal distance less than 2.5 times first dorsal-fin base; 2 spiracular folds, outer is much larger than the inner one; caudal fin small with dorsal margin about 1.8 times preventral margin; 172 total vertebral centra; dorsal disc plain colored (Ref. 55722).
Biology:  Offshore on insular shelves of the Central Indian Ocean, distribution probably restricted (Ref. 114953). Maximum size is actually unknown, presumably a small- to moderate-size species given that the half-meter holotype is sexually mature (Ref. 55722). Biology is unknown, more specimens needed (Ref. 114953).
IUCN Red List Status: Data deficient (DD); Date assessed: 24 April 2018 Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.