June Elasmobranch of the Month: White-spotted Wedgefish
White-spotted shovelnose ray (Rhynchobatus australiae)
Other names: White-spotted guitarfish, bottlenose wedgefish
Named appropriately for its shovel like appearance, the white-spotted shovelnose ray has an elongated triangular-shaped snout. The dorsal side tends to be a grey/brown-yellow in colouration with a white scattering of white spots and two well developed dorsal fins (the first larger than the second). The ventral side is white. Behind each eye there are also some thorns visible! This species can reach 3 meters ( 10 ft) in length and are ovoviviparous! Ovoviviparous means the pups will develop inside the mother but with no placenta to give them nutrients. Instead, they get the nutrients from a yolk sac!
Found in the waters of the Indian Ocean and the western Pacific Ocean (Indo-West Pacific), the white-spotted shovelnose ray mostly inhabits coastal waters over the continental shelf in bays and estuarine systems (Campagno and Last, 2009).
This species eats animals predominately found on the seafloor, such as crabs, shrimp and clams as well as bottom-swelling fish!
The white-spotted shovelnose ray is listed as “Critically Endangered” on the IUCN Red List of Endangered Species.
Unfortunately caught as both a target species and as bycatch, this species of ray is highly desirable for its fins in southeast Asia for the shark fin trade (White and McAuley, 2003). Within its range, the white-spotted shovelnose ray is also exploited by target gill net fisheries and a frequent bycatch species in trawl nets (White and McAuley, 2003).
Compagno LJV and Last PR. 1999. Rhinidae (=Rhynchobatidae). Wedgefishes. In Carpenter KE and Niem V (eds.). FAO identification guide for fishery purposes. The Living Marine Resources of the Western Central Pacific. FAO, Rome. pp 1418-1422.
White WT and McAuley R. 2003. Rhynchobatus australiae. The IUCN Red List of Threatened Species. (SSG Australia and Oceania Regional Workshop, March 2003).