Overview

Brief Summary

Biology

Smalleyed rays are carnivorous fish that prey on small fish that dwell on the sea bottom (3) (8), using their interlocking teeth to grasp and crush the food (3). The weak electrical discharges that rays are capable of producing are thought to be used in interactions with other rays, as electrical activity is more frequent when they are in pairs or groups rather than solitary (6). The smalleyed ray breeds in summer in the English Channel (2), producing eggs encased in a horny oblong case with four stiff, pointed tips (5) (8). A female lays between 54 and 61 eggs each year, depositing the precious capsules in sandy or muddy flats (8).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Description

Like other skates and rays, the most notable feature of the smalleyed ray is its large pectoral fins that provide gentle propulsion through the water (3). From above, the smalleyed ray appears rhomboid in shape (4), with greyish, olive or pale brown skin patterned with thin light streaks (2). Its snout is slightly pointed (4), and the underside, where the mouth is situated (3), is white (2). The long tail is slender (5), and contains muscles capable of emitting weak electrical discharges (6).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Comprehensive Description

Biology

Found on sandy bottoms, from inshore waters to about 100 m in tidal areas (Ref. 3167). Feed on fishes (Ref. 3167). Oviparous. Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (Ref. 205). Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats (Ref. 205). Egg capsules are 6.6-10.0 cm long and 4.1-6.3 cm wide (Ref. 41250). About 54-61 eggs are laid by an individual in a year (Ref. 41250).
  • McEachran, J.D. and K.A. Dunn 1998 Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes: Rajidae). Copeia 1998(2):271-290. (Ref. 27314)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Description

 Raja microocellata is a small skate and can grow up to 80 cm in length. It has a dorsoventrally flattened body with conspicuously small eyes and spiracles at the top of the head. It has a very pointed snout. The tail starts from rhomboid pectoral discs. Its dorsal region is greyish olive to light brown in colour with light blotches and long white bands, while the underside is white.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

©  The Marine Biological Association of the United Kingdom

Source: Marine Life Information Network

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

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.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Eastern Atlantic: southwestern England and Ireland to Rio de Oro in Western Sahara; absent from the North Sea and the Mediterranean.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Eastern Atlantic including southern North Sea.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© FishWise Professional

Source: FishWise Professional

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Range

Occurs along the Atlantic coast of northwest Europe, from Gibraltar to the British Isles, but is only abundant at a few sites, such as the Bristol Channel, UK, and Bertheaume Bay, France (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Dorsal spines (total): 0; Analspines: 0; Analsoft rays: 0
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Size

Maximum size: 800 mm TL
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© FishWise Professional

Source: FishWise Professional

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Max. size

80.0 cm TL (male/unsexed; (Ref. 41333)); 86 cm TL (female); max. published weight: 4,500 g (Ref. 4699)
  • International Game Fish Association 1991 World record game fishes. International Game Fish Association, Florida, USA. (Ref. 4699)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Diagnostic Description

Eyes conspicuously small; dorsal fins close-set, no thorns between; upper surface predominantly spinulose, underside almost smooth in young, but head and centre of disc prickly in larger specimens; orbital thorns separate, a regular row of about 50 thorns from nape to first dorsal fin; upper surface greyish, olive to light brown with light blotches and long bands, underside white (Ref. 3167).
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Habitat and Ecology

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.

Systems
  • Marine
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Environment

demersal; marine; depth range ? - 100 m (Ref. 4426)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Depth range based on 848 specimens in 1 taxon.
Water temperature and chemistry ranges based on 45 samples.

Environmental ranges
  Depth range (m): 10 - 90
  Temperature range (°C): 9.891 - 18.142
  Nitrate (umol/L): 6.121 - 9.098
  Salinity (PPS): 34.465 - 35.993
  Oxygen (ml/l): 4.414 - 6.278
  Phosphate (umol/l): 0.481 - 0.725
  Silicate (umol/l): 2.781 - 5.452

Graphical representation

Depth range (m): 10 - 90

Temperature range (°C): 9.891 - 18.142

Nitrate (umol/L): 6.121 - 9.098

Salinity (PPS): 34.465 - 35.993

Oxygen (ml/l): 4.414 - 6.278

Phosphate (umol/l): 0.481 - 0.725

Silicate (umol/l): 2.781 - 5.452
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

 The small-eyed ray is a coastal and inshore demersal species inhabiting the inner continental shelf waters down to a depth of 100 m. Usually found on sand and rock-sand bottoms.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

©  The Marine Biological Association of the United Kingdom

Source: Marine Life Information Network

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Depth: 0 - 100m.
Recorded at 100 meters.

Habitat: demersal.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© FishWise Professional

Source: FishWise Professional

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

The smalleyed ray inhabits inshore and coastal waters (2), favouring sandy bays and sandbanks (1) (7).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Life Cycle

Oviparous (Ref. 3167). Paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (Ref. 205).
  • Breder, C.M. and D.E. Rosen 1966 Modes of reproduction in fishes. T.F.H. Publications, Neptune City, New Jersey. 941 p. (Ref. 205)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Expectancy

Lifespan, longevity, and ageing

Maximum longevity: 9 years (wild)
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Raja microocellata

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 8
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
NT
Near Threatened

Red List Criteria

Version
3.1

Year Assessed
2006

Assessor/s
Ellis, J.

Reviewer/s
Valenti, S.V. & Fowler, S.L. (Shark Red List Authority)

Contributor/s

Justification
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.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Status

Classified as Lower Risk/Near Threatened (LR/nt) on the IUCN Red List (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

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.

Population Trend
Decreasing
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Major Threats
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).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Near Threatened (NT)
  • IUCN 2006 2006 IUCN red list of threatened species. www.iucnredlist.org. Downloaded July 2006.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Smalleyed rays are both gamefish and a minor component of commercial fisheries (8), and their patchy distribution and localised abundance may make this species vulnerable to over-fishing. In addition, a preference for inshore and coastal habitat makes it more susceptible to habitat degradation and other human disturbances (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation Actions

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).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

At present, there are no known specific conservation measures in place for this species.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Importance

fisheries: minor commercial; gamefish: yes; price category: medium; price reliability: questionable: based on ex-vessel price for species in this genus
  • International Game Fish Association 1991 World record game fishes. International Game Fish Association, Florida, USA. (Ref. 4699)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Smalleyed ray

The smalleyed ray (Raja microocellata) is a species of fish in the Rajidae family. It is found off the coasts of France, Ireland, Morocco, Portugal, Spain, the United Kingdom, and the Western Sahara. Its natural habitats are open seas and shallow seas. It is threatened by habitat loss.

Source

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!