Rhinobatos austini Ebert & Gon, 2017

Ebert, David A., Wintner, Sabine P. & Kyne, Peter M., 2021, An annotated checklist of the chondrichthyans of South Africa, Zootaxa 4947 (1), pp. 1-127 : 76

Rhinobatos austini Ebert & Gon, 2017

Austin’s Guitarfish

Rhinobatos austini Ebert & Gon, 2017: 205 , figs. 1–6. Holotype: SAIAB 75223 . Type locality: Near Port Shepstone , KwaZulu-Natal, South Africa, 30°50'S, 30°29'E.

Local synonymy: Rhinobatus annulatus (Natal form): Wallace, 1967b: 27, fig. 15 (in part); Compagno et al., 1989: 78, pl. (in part); Heemstra & Heemstra, 2004: 78. Rhinobatos holcorhynchus: Séret et al., 2016a: 98 , fig. 10.20 (in part, illustration is of R. austini ). Rhinobatos austini: Ebert & Gon, 2017: 205 , Figs. 1 –6.

South Africa voucher material: Holotype: SAIAB 75223 ; paratypes: SAIAB 186420 , SAIAB 193574 . Non-type: SAIAB 11125 .

South African distribution: Port Shepstone north to KZN border with Mozambique.

Remarks: Accounts by Wallace (1967b, see fig. 15) and Compagno et al. (1989, see illustration on p. 79) described a Rhinobatos annulatus “Natal ” form that was distinguished by large brown spots from the “Cape” form. However, the “Natal” form is actually Rhinobatos austini , while the “Cape” form, which is now assigned to the genus Acroteriobatus , has numerous small eyespots on its dorsal surface. Furthermore, the recently described R. austini was also misidentified with R. holcorhynchus due to both species having a black teardrop-shaped blotch on the ventral surface of its snout. Recent re-examination of specimens from Mozambique and Madagascar has expanded the known range of R. austini . This species appears to inhabit a mostly coastal habitat from inshore to 107 m, but mostly less than 75 m depth, while R. holcorhynchus appears to occur in deeper water at depths from 75 m to at least 350 m ( Séret et al., 2016a; Ebert & Gon, 2017). The illustration in the species account of R. holcorhynchus in Séret et al. (2016a, see fig. 10.20) is actually R. austini .

Conservation status: DD (2019).

Figures

FIGURE 1. Map showing localities mentioned in the text. 1 = Orange River, 2 = Port Nolloth, 3 = Doring Bay, 4 = St. Helena Bay, 5 = Cape Columbine, 6 = Saldana Say, 7 = Langebaan Lagoon, 8 = Cape Town, 9 = Table Bay, 10 = Cape Peninsula, 11 = Cape Point, 12 = False Bay, 13 = Cape Agulhas, 14 = Mossel Bay, 15 = Knysna, 16 = Plettenberg Bay, 17 = Cape St. Francis, 18 = Algoa Bay, 19 = Port Alfred, 20 = East London, 21 = Coffee Bay, 22 = Port St. Johns, 23 = Port Shepstone, 24 = Durban, 25 = Richards Bay, 26 = Sodwana Bay, 27 = Kosi Bay. The grey line depicts the former Transkei coast.