||Aptychotrema timorensis Last, 2004
||Spotted Shovelnose Ray
||Last, P.R., Séret, B. and 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.
||Previously listed as Aptychotrema sp. nov. A. This species has recently been described (Last 2004) and is a distinct member of the endemic East Indo-West Pacific genus Aptychotrema, of which there are three valid species in Australian waters.
|Red List Category & Criteria:
||Last, P.R., Kyne, P.M. & Sherman, C.S.
||Dulvy, N.K. & Lawson, J.
||Kyne, P.M., Walls, R.H.L., Simpfendorfer, C. & Chin, A.
The Spotted Shovelnose Ray (Aptychotrema timorensis) is presently known from only a few specimens. One specimen was taken from the continental shelf at 124 m in the Timor Sea, at the edge of the Australian Fishing Zone (adjacent to Indonesian waters). Additional specimens recently located in a Taiwanese collection are presumably from northern Australia, where Taiwanese trawlers used to operate.
The population size is suspected to be very small as considerable survey work has failed to find other specimens. About 650 large Thai pair trawlers from the port of Merauke in West Papua operate in the Arafura Sea, which lies adjacent to the Timor Sea. This fishery is unregulated and batoids compose a substantial portion of the catch, all of which is retained and marketed. Although the impact of fishing on this species is unknown, the potential area of occurrence of the Spotted Shovelnose Ray faces unregulated fishing and this is of particular concern due to its apparent rarity, inferred small population size and limited distribution.
While there is considerable uncertainty concerning the status of this species, a Vulnerable assessment is warranted due to an estimated extent of occurrence (EOO) of <20,000 km², occurrence in <10 locations, and an inferred continuing decline in the number of mature individuals. Continuing decline in this population is inferred, given that batoids make up a significant proportion of the catch in unregulated fisheries in Indonesian waters where this species may occur. It is even possible that steep declines may have occurred already for this species as there have only been a few specimens encountered despite extensive survey work throughout their range. Further information may result in a lower category being more appropriate. Conversely, an increase in fishing pressure would likely drive the species into a higher category.
|Previously published Red List assessments:|
- 2006 – Vulnerable (VU)
- 2003 – Least Concern (LC)
|Range Description:||As currently known, the Spotted Shovelnose Ray is restricted to a small area of the Timor Sea off northern Australia (Last and Stevens 2009). It is presumed to be restricted to the east of its presently known location as ridges would impede the movement of the species to the west. Originally known from only one specimen from the Timor Sea, some additional specimens (presumably originating from northern Australia, but exact location unknown) have been located in the National Museum of Marine Biology and Aquarium (NMMBP) collection in Taiwan (W.T. White, CSIRO. pers. comm., February 2015). Its estimated extent of occurrence (EOO) is ~18,000 km², and this species is likely to be patchy throughout this range, rather than be evenly distributed. The number of locations is unknown, but is inferred to be <10.|
Australia (Northern Territory)
|FAO Marine Fishing Areas:|
Pacific – western central
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||Unknown|
|♦ Number of Locations:||1-9|
|♦ Lower depth limit (metres):||124|
|♦ Upper depth limit (metres):||124|
|Range Map:||Click here to open the map viewer and explore range.|