Irolita westraliensis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Arhynchobatidae

Scientific Name: Irolita westraliensis Last & Gledhill, 2008
Common Name(s):
English Western Round Skate
Taxonomic Notes:

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2015
Date Assessed: 2015-02-20
Assessor(s): Awruch, C.A. & White, W.T.
Reviewer(s): Walls, R.H.L. & Kyne, P.M.
Contributor(s): Kyne, P.M.
Facilitator/Compiler(s): Kyne, P.M. & Walls, R.H.L.

The Western Round Skate (Irolita westraliensis) is a poorly-known skate, endemic to a narrow area off Western Australia. Recent taxonomic revision has split the Western Round Skate from the southern form, the Southern Round Skate (I. waitii), and as such it has a restricted range on the outer continental shelf and upper slope at depths of 140–210 m. Its range overlaps with some trawling activities, but there is no information available on bycatch. Spatial closures would provide the species with some refuge from fishing. However, there is insufficient information available to assess the species beyond Data Deficient and details on bycatch and spatial occurrence are required to make an informed assessment.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

The Western Round Skate is endemic to Western Australia with a restricted range, known only from the outer continental shelf between Exmouth Gulf (21°33′S, 114°05′E) and Imperieuse Reef (18°24′S, 118°29′E) (Last and Gledhill 2008, Last and Stevens 2009).

Countries occurrence:
Australia (Western Australia)
FAO Marine Fishing Areas:
Indian Ocean – eastern
Additional data:
Lower depth limit (metres):210
Upper depth limit (metres):140
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There are no details of population size, structure or trends.
Current Population Trend:Unknown
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:

This skate occurs on the outer continental shelf at depths of 140–210 m (Last and Stevens 2009). It reaches at least 43 cm total length (TL) and adult males mature at about 34–35 cm TL (Last and Gledhill 2008, Last and Stevens 2009).


Use and Trade [top]

Use and Trade: This skate is not utilized or traded.

Threats [top]

Major Threat(s):

The range of this species overlaps with the Pilbara Fish Trawl Fishery, although bycatch levels are unknown.

Conservation Actions [top]

Conservation Actions: No species-specific conservation actions are currently in place. All sharks and rays are commercially protected under Western Australian law. This regulation essentially restricts the retention of all shark and ray products by commercial fishing vessels other than those operating in the State's managed shark fishery. Research is required to better define its full range, estimate abundance, and examine life history traits. Considerable areas of Western Australia's North Coast Bioregion are permanently closed to all trawling through spatial management arrangements, and there have been reductions in effort quota in the Pilbara Fish Trawl Fishery since 2009 (Fletcher and Santoro 2014).

Classifications [top]

9. Marine Neritic -> 9.2. Marine Neritic - Subtidal Rock and Rocky Reefs
suitability:Suitable season:resident major importance:Yes
9. Marine Neritic -> 9.4. Marine Neritic - Subtidal Sandy
suitability:Suitable season:resident major importance:Yes
9. Marine Neritic -> 9.5. Marine Neritic - Subtidal Sandy-Mud
suitability:Suitable season:resident major importance:Yes

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:No
In-Place Land/Water Protection and Management
  Conservation sites identified:No
  Occur in at least one PA:Yes
  Area based regional management plan:No
  Invasive species control or prevention:Not Applicable
In-Place Species Management
  Harvest management plan:No
  Subject to ex-situ conservation:No
In-Place Education
  Subject to recent education and awareness programmes:No
  Included in international legislation:No
  Subject to any international management/trade controls:No
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Fletcher, W.J. and Santoro, K. 2014. Status Reports of the Fisheries and Aquatic Resources of Western Australia 2013/14: The State of the Fisheries. Department of Fisheries, Western Australia.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: (Accessed: 19 November 2015).

IUCN SSC Shark Specialist Group. Specialist Group website. Available at:

Last, P.R. and Gledhill, D.C. 2008. A new species of round skate, Irolita westraliensis sp. nov. (Rajoidei: Arhynchobatidae), from northern Western Australia. CSIRO Marine and Atmospheric Research Paper 21: 173-181.

Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood, Australia.

Sainsbury, K.J., Kailola, P.J. and Leyland, G.G. 1985. Continental shelf fishes of northern and north-western Australia. An illustrated Guide. CSIRO Division of Fisheries Research, Canberra, Australia.

Citation: Awruch, C.A. & White, W.T. 2015. Irolita westraliensis. The IUCN Red List of Threatened Species 2015: e.T195457A68631044. . Downloaded on 18 June 2018.
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