60127-3

Aetomylaeus bovinus 

Scope: Mediterranean
Language: English
Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_offStatus_en_offStatus_cr_onStatus_ew_offStatus_ex_off

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Myliobatiformes Myliobatidae

Scientific Name: Aetomylaeus bovinus (Geoffroy Saint-Hilaire, 1817)
Regional Assessments:
Common Name(s):
English Bullray, Duckbill
Synonym(s):
Myliobatis bovina Geoffroy Saint-Hilaire, 1817
Pteromylaeus bovina (Geoffroy Saint-Hilaire, 1817)
Pteromylaeus bovinus (Geoffroy Saint-Hilaire, 1817)
Taxonomic Source(s): Eschmeyer, W.N., Fricke, R. and Van der Laan, R. (eds). 2016. Catalog of Fishes: genera, species, references. Updated 29 September 2016. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 29 September 2016).
Taxonomic Notes: This species is often confused with Myliobatus aquila.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2c (Regional assessment) ver 3.1
Year Published: 2016
Date Assessed: 2016-03-25
Assessor(s): Walls, R.H.L. & Buscher, E.
Reviewer(s): Dulvy, N.K., Kemp, J.R. & Allen, D.J.
Contributor(s): Wintner, S.
Facilitator/Compiler(s): Walls, R.H.L. & Dulvy, N.
Justification:

Mediterranean regional assessment: Critically Endangered (CR)

The Bullray (Pteromylaeus bovinus) is considered widespread in the Mediterranean Sea, but there are few records. It can be inferred from available knowledge of other myliobatid rays that this species is susceptible to a range of inshore fishing gears and has a sensitive life history with a low fecundity (three to four pups per litter). In some areas of the Mediterranean Sea, fishing pressure is intense and unregulated across the Bullray's preferred habitat. A population reduction of at least 80% over three generations (45 years) is suspected based on its shallow depth range, slow life history, high catchability, and paucity of records. The Bullray is therefore assessed as Critically Endangered in the Mediterranean region.

Geographic Range [top]

Range Description:

The Bullray occurs throughout shallow, coastal and offshore waters of the Mediterranean Sea (Ebert and Stehmann 2013). Outside the Mediterranean Sea the range of the species extends in the eastern Atlantic Ocean from northwestern Spain to the Indian Ocean.

Countries occurrence:
Native:
Albania; Algeria; Bosnia and Herzegovina; Croatia; Cyprus; Egypt (Egypt (African part), Sinai); France (Corsica, France (mainland)); Gibraltar; Greece (East Aegean Is., Greece (mainland), Kriti); Israel; Italy (Italy (mainland), Sardegna, Sicilia); Lebanon; Libya; Malta; Monaco; Montenegro; Morocco; Palestinian Territory, Occupied; Slovenia; Spain (Baleares, Spain (mainland)); Syrian Arab Republic; Tunisia; Turkey (Turkey-in-Asia, Turkey-in-Europe)
FAO Marine Fishing Areas:
Native:
Mediterranean and Black Sea
Additional data:
Lower depth limit (metres):30
Range Map:60127-3

Population [top]

Population:

This species was not caught in a trawl survey of the entire northern Mediterranean basin between 1994 and 1999 conducted as part of the International Trawl Survey in the Mediterranean (MEDITS) programme (Baino et al. 2001). Similarly, Damalas and Vassilopoulou (2011) found none during trawl surveys in the Aegean Sea from 1995 to 2006. Only one specimen in 1948 was caught in scientific trawl surveys conducted in the Adriatic Sea between 1948 and 2005 (Ferretti et al. 2013). However, in recent years others have reported small numbers of this species in the northern Mediterranean Sea, including Puerto de Mazarrón off southeast Spain (Hernández-Orts et al. 2010), the southeast Aegean Sea (Corsini-Foka and Frantzis 2009), the eastern Ionian Sea (Zogaris and Dussling 2010), and Iskenderun Bay off Turkey (Başusta et al. 2012), which suggests it still occurs in the Mediterranean region. Furthermore, capture of pregnant females in the northern Adriatic Sea suggests this species is reproducing in the area (Dulcic et al. 2008), hence not just a vagrant in these waters.

Nothing is known of population size or trends in the Mediterranean Sea, except that the Bullray appears to be extremely rare throughout the region. It can be inferred from the status of similar myliobatid rays in the region (e.g., the Common Eagle Ray, Myliobatis aquila) that the Bullray is declining as a result of overfishing, which is unsustainable across the entirety of its Mediterranean range. The Common Eagle Ray is listed as Vulnerable in the region, although it has a much greater depth range than the Bullray (i.e., greater refuge from fishing activity) and is far more commonly sighted in surveys and fisheries. Due to the severe rarity of the Bullray, its absence from trawl surveys and fisheries in several localities from which it previously occurred, and its very narrow depth range overlapping entirely with both artisanal and commercial fishing activity, a population reduction of at least 80% over three generations (45 years) is suspected.

Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:

This benthic and semi- to epipelagic species occurs in tropical to warm temperate coastal waters between the surf zone and depths of 30 m, and sometimes farther offshore. It also occurs in shallow bays, lagoons, and estuaries where salinity is low (Ebert and Stehmann 2013).

In the northern Adriatic Sea, Dulcic et al. (2008) found pregnant females bearing near-term embryos, ranging between 37 and 45 cm disc width (DW) and weighing 740−1,080 g. Some of the mature specimens were among the largest recorded to date, at 154−222 cm DW and 68−116 kg total weight. Similarly, Lipej et al. (2008) reported maximum sizes of 113.5 cm DW (male) and 222 cm DW (female) from the northern Adriatic Sea. The maximum total length on record is a 294 cm female.

The Bull Ray's generation length is inferred to be around 15 years, based on the fact that the Lusitanian Cownose Ray (Rhinoptera marginata) – another member of the Myliobatidae family that also occurs in Mediterranean waters – has a generation length of around 11 years (Neer and Thompson 2005).

Systems:Marine
Generation Length (years):15
Movement patterns:Unknown

Use and Trade [top]

Use and Trade: The Bullray is not exploited or traded commercially in the Mediterranean region.

Threats [top]

Major Threat(s):

Little information is available on catches of the Bullray outside of South Africa, but given the species’ inshore occurrence, it is likely taken in coastal artisanal fisheries across much of its range.

Another threat likely affecting this species in the Mediterranean region is habitat degradation from human activities in the coastal zone (e.g., land development and pollution). Activities in the coastal zone and adjacent waterfront may affect important nursery habitat.

Conservation Actions [top]

Conservation Actions:

There are currently no species-specific measures in place. Much research is required on the Bullray's population, size, trend, habitat, ecology, and threats. In order to protect the Bullray, its habitat needs to be protected, its harvest monitored and managed, and implementation of education and awareness programs could be beneficial.


Citation: Walls, R.H.L. & Buscher, E. 2016. Aetomylaeus bovinus. The IUCN Red List of Threatened Species 2016: e.T60127A81163810. . Downloaded on 22 June 2018.
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