Abstract
The recently resurrected genus Acroteriobatus is represented in the western Indian Ocean by eight species, including a new guitarfish Acroteriobatus omanensis sp. nov. This small species (reaching ~60 cm TL) was discovered off Oman in an investigation of the chondrichthyan fauna of the Arabian in 2002 and 2003. Its distinctiveness from other members of the genus Acroteriobatus is strongly supported by molecular data. Acroteriobatus omanensis sp. nov. differs from all other members of the genus by its very narrowly pointed snout and having a dense pattern of small, symmetrically arranged ocelli each consisting of a white spot surrounded by a darker rim. Acroteriobatus annulatus and A. ocellatus have a more-or-less ocellated dorsal colour pattern but the markings are larger and differ in form (ocelli consisting of a small dark central spot surrounded by a dark-edged pale ring in A. annulatus; larger, irregularly shaped ocelli with pale centres surrounded by a dark brown rim in A. ocellatus).
References
Compagno, L.J.V. (1984) FAO Species Catalogue. Vol. 4, Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fisheries Synopsis, 125, (4, 1), 1–655.
Henderson, A.C., McIlwain, J.L., Al-Oufi, H.S. & Al-Sheili, S. (2007) The Sultanate of Oman shark fishery: species composition, seasonality and diversity. Fisheries Research, 86, 159–168.
http://dx.doi.org/10.1016/j.fishres.2007.05.012Henderson, A.C., Reeve, A.J., Jabado, R.W. & Naylor, G.J.P. (2016) Taxonomic assessment of sharks, rays and guitarfishes (Chondrichthyes: Elasmobranchii) from south-eastern Arabia, using the NADH dehydrogenase subunit 2 (NADH2) gene. Zoological Journal of the Linnean Society, 176, 399–442.
http://dx.doi.org/10.1111/zoj.12309Last, 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.
http://dx.doi.org/10.1007/s10228-004-0211-0Last, P.R., Séret, B. & Naylor, G.J.P. (2016) 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.
http://dx.doi.org/10.11646/zootaxa.4117.4.1Moore, B.M., McCarthy, I.D., Carvalho, G.R. & Peirce, R. (2012) Species, sex, size and male maturity composition of previously unreported elasmobranch landings in Kuwait, Qatar and Abu Dhabi Emirate. Journal of Fish Biology, 80, 1619–1642. http://dx.doi.org/10.1111/j.1095-8649.2011.03210.x
Müller, J. & Henle, F.G.J. (1841) Systematische Beschreibung der Plagiostomen. Veit, Berlin, 200 pp.
http://dx.doi.org/10.5962/bhl.title.6906Nair, R.V. & Lal Mohan, R.S. (1973) On a new deep sea skate, Rhinobatos variegatus, with notes on the deep sea sharks Halaelurus hispidus, Eridacnis radcliffei and Eugaleus omanensis from the Gulf of Mannar. Senckenbergiana Biologica, 54 (1, 3), 71–80.
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.
http://dx.doi.org/10.1111/j.1096-3642.1926.tb02228.xRandall, J.E. & Compagno, L.J.V. (1995) A review of the guitarfishes of the genus Rhinobatos (Rajiformes: Rhinobatidae) from Oman, with description of a new species. Raffles Bulletin of Zoology, 43 (2), 289–298.
Séret, B., Last, P.R. & Naylor, G.J.P. (2016) Guitarfishes - Family Rhinobatidae. In: Last, P.R., White, W.T., Carvalho, M.R. de, Séret, B., Stehmann, M.F.W. & Naylor, G.J.P. (Eds.), Rays of the World. CSIRO Publishing, Melbourne. [in press]