Aetomylaeus vespertilio 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Myliobatidae

Scientific Name: Aetomylaeus vespertilio
Species Authority: (Bleeker, 1852)
Common Name(s):
English Ornate Eagle Ray, Reticulate Eagle Ray
Aetomylaeus reticulates (Teng, 1962)
Myliobatis vespertilio Bleeker, 1852
Taxonomic Notes: Poorly represented in collections. The lack of specimens has caused some nomeclatural problems that have not been fully resolved. Older scientific names may apply to earlier growth stages of this species.

Assessment Information [top]

Red List Category & Criteria: Endangered A2bd+3d+4d ver 3.1
Year Published: 2006
Date Assessed: 2006-01-31
Assessor(s): White, W.T.
Reviewer(s): Kyne, P.M., Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)
Aetomylaeus vespertilio is a large (to 240 cm disc width), uncommon eagle ray which has not been sighted in any great numbers since its description more than 160 years ago. This species would be highly susceptible to a variety of fishing methods in regions where the level of exploitation of marine resources is very high and is increasing (e.g., India, Thailand, Taiwan and Indonesia). It is occasionally caught by the rhynchobatid gillnet fishery that operates in SE Asia. In Australian waters the fishing pressure would not be very high but it is rarely observed there. It is suspected to have limiting life history parameters similar to other myliobatid rays (including low fecundity). This species is assessed as Endangered under the criteria of A2bd+3d+4d due to the very high (and increasing) level of fishing pressure in inshore regions where it occurs, which is of great concern for this large, uncommon inshore species with limiting life history characteristics and high susceptibility to capture.

Geographic Range [top]

Range Description: Sporadic distribution in the Western and Eastern Indian, Western Central and Northwest Pacific.
Countries occurrence:
Australia (Northern Territory, Queensland, Western Australia); China; India; Indonesia (Jawa, Kalimantan); Malaysia; Maldives; Mozambique; Taiwan, Province of China; Thailand
FAO Marine Fishing Areas:
Indian Ocean – western; Indian Ocean – eastern; Pacific – northwest; Pacific – western central
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Appears to be naturally uncommon, rarely observed.
Current Population Trend: Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology: Little known species. Occurs on the inner continental shelf to depths of 110 m over soft sandy substrate (Compagno and Last 1999). Reproductive biology, age and growth and dietary compositions are unknown for this species. Suspected low fecundity as with other myliobatids, for example Aetobatus narinari and Aetomylaeus nichofii, which bear litters of up to four offspring (Last and Stevens 1994, Compagno and Last 1999).

Life history parameters
Age at maturity (years): Unknown.
Size at maturity (total length cm): Unknown.
Longevity (years): Unknown.
Maximum size (total length/disc width): 240 cm DW (W. White, unpubl. data) 160 cm DW, 385 cm TL (Compagno and Last 1999).
Size at birth (cm): Unknown.
Average reproductive age (years): Unknown.
Gestation time (months): Unknown.
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: Up to 4 (based on similar species).
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
Systems: Marine

Threats [top]

Major Threat(s): Highly susceptible to a variety of inshore demersal fisheries, including trawls, gillnets and trammel nets which operate intensively throughout its range (e.g., India, Thailand, Taiwan and Indonesia). All individuals caught are retained in most areas. Local eagle ray species are marketed in considerable numbers in Thailand and Malaysia (Compagno and Last 1999). A. maculates is occasionally landed in low numbers in the fish markets of Jakarta (Indonesia) by trawlers and is occasionally caught by the rhynchobatid gillnet fishery that operates in SE Asia (W. White, unpublished data). Even though once common, eagle rays are now rare in the Gulf of Thailand (Compagno and Last 1999). Intensive demersal fisheries occur in India, in the species' known distribution (Hanfee 1999). There is very high level of exploitation on the habitat that this species occurs in throughout its range.

Conservation Actions [top]

Conservation Actions: None in place. Market surveys are currently being conducted for elasmobranchs in Indonesia.

The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) are required to facilitate the conservation and sustainable management of all chondrichthyan species in the region. See Anon. (2004) for an update of progress made by nations in the range of A. vespertilio.

Classifications [top]

9. Marine Neritic -> 9.1. Marine Neritic - Pelagic
suitability: Marginal  
9. Marine Neritic -> 9.9. Marine Neritic - Seagrass (Submerged)
suitability: Marginal  
9. Marine Neritic -> 9.10. Marine Neritic - Estuaries
suitability: Unknown  
10. Marine Oceanic -> 10.1. Marine Oceanic - Epipelagic (0-200m)
suitability: Marginal  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.3. Unintentional effects: (subsistence/small scale)
♦ timing: Ongoing ♦ scope: Unknown ♦ severity: Unknown ⇒ Impact score: Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale)
♦ timing: Ongoing ♦ scope: Unknown ♦ severity: Unknown ⇒ Impact score: Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

0. Root -> 100.1. OLD 1.1.1-Policy-base actions->Management plans->Development
1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Anonymous. 2004. Report on the implementation of the UN FAO International Plan of Action for Sharks (IPOA–Sharks). AC20 Inf. 5. Twentieth meeting of the CITES Animals Committee, Johannesburg (South Africa), 29 March–2 April 2004.

Compagno, L.J.V. and Last, P.R. 1999. Myliobatidae. Eagle rays. In: K.E. Carpenter and V.H. Niem (eds) FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 3. Batoid Fishes, Chimaeras and Bony Fishes Part 1 (Elopidae to Linophrynidae). pp. 1511-1519. Food and Agriculture Organization of the United Nations, Rome.

Hanfee, F. 1999. Management of shark fisheries in two Indian coastal states: Tamil Nadu and Kerala. In: R. Shotton (ed.) Case studies of the management of elasmobranch fisheries. FAO technical paper 378/1, FAO Rome.

IUCN. 2006. 2006 IUCN Red List of Threatened Species. Downloaded on 04 May 2006.

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

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

Citation: White, W.T. 2006. Aetomylaeus vespertilio. The IUCN Red List of Threatened Species 2006: e.T60121A12307845. . Downloaded on 25 June 2016.
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