Rhinobatos austini sp. n. is described from the southwestern Indian Ocean based on four specimens collected from the KwaZulu-Natal Province, South Africa and from Mozambique. The new species, with one exception, can be distinguished from all other members of this genus by a prominent teardrop-shaped dark blotch on the ventral surface of its snout. Its closest congener, R. holcorhynchus, also has a prominent teardrop-shaped blotch on its snout, but the new species differs from it by a lack of prominent thorns and tubercles on it dorsal disc surface and a very striking dorsal surface colour pattern of paired spots, some forming darker transverse bands across its back. Geographically, these two species broadly overlap, but R. austini appears to be a shallow, more coastal species (<1–107 m) compared to R. holcorhynchus that has a mostly offshore (75–254 m) depth distribution.
Barnard, K.H. (1927) A monograph of the marine fishes of South Africa. Part 2 (Amphioxus, Cyclostomata, Elasmobranchii, and Teleostei-Isospondyli to Heterosomata). Annals of the South African Museum, 21, 419–1065.
Bonfil, R. & Abdallah, M. (2004) Field identification guide to the sharks and rays of the Red Sea and Gulf of Aden. FAO Species Identification Guide for Fisheries Purposes. FAO, Rome, pp. 1–71.
Compagno, L.J.V. (1999) An overview of chondrichthyan systematics and biodiversity in southern Africa. Transactions of the Royal Society of South Africa, 54, 75–120.
Compagno, L.J.V. (2005) Checklist of living Chondrichthyes. In: Hamlett, W.C. (Ed.), Reproductive biology and phylogeny of Chondrichthyes. Science Publishers, Inc., New Hampshire, pp. 503–548.
Compagno, L.J.V., Ebert, D.A. & Smale, M.J. (1989) Guide to the sharks and rays of southern Africa. Struik Publishers, Cape Town, 160 pp.
Compagno, L.J.V. & Last, P.R. (1999) Rhinobatidae. In: Carpenter, K.E. and Niem, V.H. (Eds.), FAO Species Identification Guide for Fishery Purposes. The living marine resources of the Western Central Pacific. Vol. 3. Batoid fishes, chimaeras and bony fishes. Part 1 (Elopidae to Linophyrnidae). FAO, Rome, pp. 1423–1430.
Compagno, L.J.V. & Randall, J.E. (1987) Rhinobatos punctifer, a new species of guitarfish (Rhinobatiformes: Rhinobatidae) from the Red Sea, with notes on the Red Sea batoid fauna. Proceedings of the California Academy of Sciences, 44 (14), 335–342.
Ebert, D.A. & van Hees, K.E. (2015) Beyond Jaws: rediscovering the ‘lost sharks’ of southern Africa. African Journal of Marine Science, 37 (2), 141–156.
Fowler, H.W. (1925) Descriptions of three new marine fishes from the Natal coast. Annals of the Natal Museum, 5 (2), 195–200.
Last, P.R., Compagno, L.J.V. & Nakaya, K. (2004) Rhinobatos nudidorsalis, a new species of shovelnose ray (Batoidea: Rhinobatidae) from the Mascarene Ridge, central Indian Ocean. Ichthyological Research, 51, 153–158.
Last, P.R., Henderson, A.C. & Naylor, G.J.P. (2016b) Acroteriobatus omanensis (Batoidea: Rhinobatidae), a new species of guitarfish from the Gulf of Oman. Zootaxa, 4144 (2), 276–286.
Last, P.R., Séret, B. & Naylor, G.J.P. (2016a) A new species of guitarfish, Rhinobatos borneensis sp. nov. with a redefinition of the family-level classification in the order Rhinopristiformes (Chondrichthyes: Batoidea). Zootaxa, 4117 (4), 451–475.
Norman, J.R. (1922) Three fishes from Zululand and Natal, collected by Mr H.W. Bell Marley; with additions to the fish fauna of Natal. Annals and Magazine of Natural History, Series 9, 9 (52), 318–322.
Norman, J.R. (1926) A synopsis of the rays of the family Rhinobatidae, with a revision of the genus Rhinobatus. Proceedings Zoological Society London, 1926 (4), 941–982.
Sabaj, M.H. (2016) Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an Online Reference. Version 6.5 (16 August 2016). American Society of Ichthyologists and Herpetologists, Washington, DC. Available from: http://www.asih.org/ (accessed 22 December 2016)
Smith, J.L.B. (1961) The sea fishes of Southern Africa. 4th Edition. Central News Agency Ltd, Johannesburg, 580 pp.
Wallace, J.H. (1967) The batoid fishes of the east coast of southern Africa. Part I: sawfishes and guitarfishes. In: South African Association for Marine Biological Research, Oceanographic Research Institute, Investigational Report. Vol. 15. Oceanographic Research Institute, Durban, pp. 1–32.
White, W.T., Last, P.R. & Naylor, G.J.P. (2016) Rhinobatos manai sp. nov., a new species of guitarfish (Rhinopristiformes: Rhinobatidae) from New Ireland, Papua New Guinea. Zootaxa, 4175 (6), 588–600.