Raja microocellata 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Rajidae

Scientific Name: Raja microocellata Montagu, 1818
Regional Assessments:
Common Name(s):
English Smalleyed Skate, Smalleyed Ray
Raia microocellata Montagu, 1818
Taxonomic Notes: There is some potential for confusion with regards common names. In some areas, smalleyed ray may be called Painted Ray or Sandy Ray, though these common names are also used for undulate ray Raja undulata and Leucoraja circularis respectively.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2006
Date Assessed: 2006-02-13
Needs updating
Assessor(s): Ellis, J.
Reviewer(s): Valenti, S.V. & Fowler, S.L. (Shark Red List Authority)
The Smalleyed Ray (Raja microocellata) is restricted primarily to the Atlantic coasts of Northwest Europe, from Gibraltar to the British Isles, although it has also been recorded further south, to Western Sahara, northwestern Africa. It is found on the continental shelf, mostly at <100 m depth. The range of this skate is smaller than many of the more common European skates and rays. It favours sandy bays and is only recorded as abundant at a few sites (e.g., Bristol Channel, UK and Bertheaume Bay, France). Raja microocellata is taken as bycatch in trawl and set net fisheries, with most landings from the Bristol Channel and is commercially important for ports in parts of southern England. Given its restricted and patchy, fragmented geographical distribution and localised abundance local populations may potentially be vulnerable to declines caused by over-fishing, habitat degradation and other anthropogenic disturbance. This species is assessed as Near Threatened on the basis of suspected declines approaching 30%, as a result of high levels of exploitation, close to meeting the criteria for Vulnerable A4d. Fishery independent data for mature R. microocellata are limited and careful monitoring of populations of this species is required to determine accurate population trends of mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:The Smalleyed Ray is restricted primarily to the Atlantic coasts of Northwest Europe, from the British Isles southwards to Gibraltar and northwestern Africa (Morocco and Western Sahara) (Stehmann and Bürkel 1989) and is most abundant in bays and other inshore sandy areas.
Countries occurrence:
France; Ireland; Morocco; Portugal; Spain; United Kingdom; Western Sahara
FAO Marine Fishing Areas:
Atlantic – northeast; Atlantic – eastern central
Additional data:
Lower depth limit (metres):100
Upper depth limit (metres):1
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Over much of its geographical range it is relatively rare, though it can be locally abundant in certain areas, for example smalleyed ray is one of the dominant rajids occurring in the Bristol Channel (ICES division VIIf), Bertheaume Bay (Brittany) and south-eastern Ireland (Fahy and O'Reilly 1990, Rousset 1990, Ellis et al. 2005a,b). No formal stock assessments have been undertaken for this species. The Smalleyed Ray's geographic range is smaller than many of the more common European skates and rays. Furthermore there are certain areas where it is particularly abundant. For example, within UK waters it is only reported occasionally in the Irish Sea and North Sea, caught in low numbers in the English Channel and is very abundant in the Bristol Channel. Hence, this inshore species seems to have a fragmented population, possibly due to the fragmented nature of its favoured habitat. Catch rates in beam trawl surveys of the Bristol Channel appear steady (Ellis et al. 2005b), though this is based on catch rates of all individuals. It is likely that the equipment used in this survey does not sample mature fish effectively, and fishery-independent data for mature fish are limited.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Juveniles tend to occur in relatively shallow water, with larger individuals more abundant further from shore, though it is uncommon in waters more than 100m deep (Ellis et al. 2005a). The Smalleyed Ray attains a maximum length of 91 cm total length (LT ) and begins to mature at 57.5-58 cm LT (Ryland and Ajayi 1984). The fecundity has been estimated at 54-61 eggs per year, with egg-laying activity peaking between June and September (Ryland and Ajayi 1984). Size at birth is approximately 10 cm TL (Ryland and Ajayi 1984).The feeding habits have been described for those populations inhabiting Carmarthen Bay (Ajayi 1977, 1982; Ellis unpublished) and the Cove of Bertheaume in Brittany (Rousset 1987) and it is known that they feed on a variety of crustaceans and teleosts (Fowler et al. 2005). Juveniles predate primarily on small shrimps and amphipods, with fishes (e.g., sand eels and dragonets) becoming more important in the diets of larger individuals.

Threats [top]

Major Threat(s): Taken as a bycatch in trawl and set net fisheries, with most landings from the Bristol Channel (ICES Division VIIf). R. microocellata is commercially important for ports in South Wales, Devon and Cornwall in the UK. Exploitation in areas further south is not known. Due to its restricted distribution, inshore habitats and overall scarcity, albeit with areas of localised abundance, it may be at risk from overfishing and habitat disturbance. Sand banks in the Bristol Channel (UK) are regularly dredged to supply the aggregate industry and the potential consequences of this activity on R. microocellata are unknown (Fowler et al. 2005).

Conservation Actions [top]

Conservation Actions: There is a minimum landing size of 40 cm for skates and rays caught in the inshore waters of South Wales. Though there are no species-specific management measures, they may benefit from more generic management measures for demersal fisheries (e.g., mesh size regulations).

Citation: Ellis, J. 2006. Raja microocellata. The IUCN Red List of Threatened Species 2006: e.T39400A10225571. . Downloaded on 20 April 2018.
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