Description:

Unmistakable deep-bodied guitarfish with a broad, blunt snout and distinctive heavy thorny ridges (of enlarged dermal denticles) over the eyes, above the “shoulders” and 
in a central dorsal ridge. Grey to sandy brown colour dorsally with white spots on fins, body and tail. Ventral surface is pale cream to white. Large spiracles positioned 
behind the eyes. The closed mouth has the shape of a long bow hence the name. The mouth has plates of crushing teeth. Tail considerably longer than disk, broad based with 
large, shark like dorsal fins and well-developed caudal fin. 
 

Maturity: Males mature 150-175cm TL, females ~ 180cm TL. Max Length: 270cm TL.
 

Inhabits continental and insular coastal shelves with a demersal habit - depth range 3-90m. Feeds mainly on demersal crustaceans and molluscs, its crushing teeth being 
adapted to break hard shells, but also teleosts. Ovoviviparous, sources vary as to the range of litter sizes cited, the largest being 2-11. Litters of 7 and 8 pups have 
been recorded in Seychelles. Dorsal thorny ridges have a defensive function. 
 

This species is not protected or subject to fishery regulations. It is caught in the hand line and anchored Long line (“Drag”) fisheries and can also be entangled in 
nets set demersally. It is a very rare component of the catch. 

Following a Green Islands Foundation GEF/Satoyama 2016-2018 project on threatened species in the arftisanal fishery, artisanal fishers agreed to relase all specimens 
caught. This was agreed amongst measures for 12 other threatened species which have been submitted to the Ministry of Fisheries and the Seychelles Fisheries Authority 
for promulgation into regulations. As of September 2021 the Authorities have not taken any action on this front and it appears the opportunity has likley been lost.

Bray, D.J. (2017), Rhina ancylostoma in Fishes of Australia, accessed 28 Aug 2018, http://fishesofaustralia.net.au/home/species/3271
Froese, R. & D. Pauly. Eds. (2018). https://www.fishbase.de/summary/Rhina-ancylostoma (28/08/18).
Kyne, P.M. et al (2019). Rhina ancylostoma. The IUCN Red List 2019: e.T41848A124421912. https://dx.doi.org/10.2305/IUCN.UK.2019-2.RLTS.T41848A124421912.en. (28/09/21).
Last, P.R. et al (2016). Rays of the World. CSIRO Publishing ISBN 9781501705328
Nevill, J.E.G. et al (2015). An identification guide for the sharks of the Seychelles Artisanal Fishery.

Nevill, J.E.G. (2019). Rhina ancylostoma, Bowmouth ray. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/rhina-ancylostoma-bloch-schneider-1801/ (Updated 28/09/21).