Overview

Comprehensive Description

Dipturus oxyrinchus (Linnaeus, 1758)

Sea of Marmara : 2500-40 (1 spc.), 12.07.1995 , North-west offshore of Marmara Island , trawl , 159 m, L. Eryilmaz .

  • Nurettin Meriç, Lütfiye Eryilmaz, Müfit Özulug (2007): A catalogue of the fishes held in the Istanbul University, Science Faculty, Hydrobiology Museum. Zootaxa 1472, 29-54: 32-32, URL:http://www.zoobank.org/urn:lsid:zoobank.org:pub:428F3980-C1B8-45FF-812E-0F4847AF6786
Public Domain

MagnoliaPress via Plazi

Source: Plazi.org

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Biology

Found in deeper slope waters (Ref. 4426), but mainly around 200 m (Ref. 3167). Found on sand and sand-rock bottoms (Ref. 6808). Feed on all kinds of bottom animals (Ref. 3167). Minimum depth reported taken from Ref. 6808. Become sexually mature at a length of about 120 cm (Ref. 35388). 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 14.0-23.5 cm long and 11.0-12.0 cm wide (Ref. 41251, 41304).
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

Distribution

Range Description

In the Northeast Atlantic this skate occurs on the outer continental shelf and continental slope from central Norway southwards (Heintz 1962, Stehmann and Brkel 1984). It is found in the Barents Sea, in the Norwegian Sea mainly along the coastline south of latitude 65N, and in very low numbers in the North Sea (Williams et al. 2008, ICES 2012). The species was last encountered in trawl surveys around the Faroe Islands in 2001, and is only occasionally caught on the Rockall Survey in offshore waters west of Scotland (ICES 2012). In the Bay of Biscay, Iberian waters, and the Azores and mid-Atlantic ridge, it is still encountered by fisheries and trawl surveys in low numbers.

This skate was historically found throughout the Mediterranean Sea in both shelf and slope areas (Stehmann and Brkel 1984), with the greatest survey catches occurring around the Corsica, Sardinia and Malta Islands, and throughout the eastern part of the basin including Dodecanese waters. By contrast it is not present in the western Mediterranean Sea, along the French and Spanish coasts, and the Northern Adriatic Sea (Serena et al. 2011). Its depth range is 90-900 m.

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

Mediterranean Sea, eastern Atlantic: Norway and North Sea to Senegal including Madeira (rare) and Canary Islands.
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

Eastern Atlantic: central Norway to Senegal, including the Faeroes, Skagerrak, Mediterranean, and the Canary and Madeira islands.
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

Physical Description

Size

Maximum size: 1500 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

150 cm TL (male/unsexed; (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

Ecology

Habitat

Habitat and Ecology

Habitat and Ecology

This demersal skate is found on sandy or muddy bottoms at depths ranging from 90900 m, and appears to be most abundant from 200500 m (Stehmann and Brkel 1984, Baino et al. 2001).

This egg laying skate has a spawning period from February to May (Stehmann and Brkel 1984, Bauchot 1987, Notarbartolo di Sciara and Bianchi 1998, Serena et al. 2010), and produces egg cases between 10 and 15 cm in length. Size at birth is 17 cm total length (TL; Ebert and Stehmann 2013). Estimated length at 50% maturity was 83.2 cm TL for males and 104.4 cm TL for females (Serena et al. 2011). Both sexes are estimated to reach sexual maturity between six and eight years. Stehmann and Brkel (1984) reported a maximum size of 150 cm TL. The generation length of this species is inferred from that of Barndoor Skate (which is slightly larger) to be around 10 years.


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

Depth range based on 3741 specimens in 1 taxon.
Water temperature and chemistry ranges based on 2514 samples.

Environmental ranges
  Depth range (m): 11 - 524
  Temperature range (°C): 6.014 - 15.663
  Nitrate (umol/L): 3.151 - 12.134
  Salinity (PPS): 34.355 - 38.670
  Oxygen (ml/l): 4.136 - 6.265
  Phosphate (umol/l): 0.186 - 0.854
  Silicate (umol/l): 2.543 - 5.968

Graphical representation

Depth range (m): 11 - 524

Temperature range (°C): 6.014 - 15.663

Nitrate (umol/L): 3.151 - 12.134

Salinity (PPS): 34.355 - 38.670

Oxygen (ml/l): 4.136 - 6.265

Phosphate (umol/l): 0.186 - 0.854

Silicate (umol/l): 2.543 - 5.968
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.
All rights reserved

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Known from seamounts and knolls
translation missing: en.license_cc_by_4_0

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Depth: 15 - 900m.
From 15 to 900 meters.
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

Environment

bathydemersal; marine; depth range 15 - 900 m (Ref. 11284), usually 200 - ? m
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 3741 specimens in 1 taxon.
Water temperature and chemistry ranges based on 2514 samples.

Environmental ranges
  Depth range (m): 11 - 524
  Temperature range (°C): 6.014 - 15.663
  Nitrate (umol/L): 3.151 - 12.134
  Salinity (PPS): 34.355 - 38.670
  Oxygen (ml/l): 4.136 - 6.265
  Phosphate (umol/l): 0.186 - 0.854
  Silicate (umol/l): 2.543 - 5.968

Graphical representation

Depth range (m): 11 - 524

Temperature range (°C): 6.014 - 15.663

Nitrate (umol/L): 3.151 - 12.134

Salinity (PPS): 34.355 - 38.670

Oxygen (ml/l): 4.136 - 6.265

Phosphate (umol/l): 0.186 - 0.854

Silicate (umol/l): 2.543 - 5.968
 
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

Life History and Behavior

Life Cycle

Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). Egg cases laid from spring to early summer (Ref. 3167). Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (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

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Dipturus oxyrinchus sp2

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

Statistics of barcoding coverage: Dipturus oxyrinchus sp1

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 56
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

Barcode data: Dipturus oxyrinchus

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File
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

Statistics of barcoding coverage: Dipturus oxyrinchus

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 50
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
2015

Assessor/s
Ellis, J., Abella, A., Serena, F., Stehmann, M.F.W. & Walls, R.

Reviewer/s
Dulvy, N.

Contributor/s
Ungaro, N., Tinti, F., Bertozzi, M., Mancusi, C., Notarbartolo di Sciara, G. & Fordham, S.

Justification

Longnosed Skate (Dipturus oxyrinchus) is a demersal species found on sandy or muddy bottoms at depths of 90900 m. The large body size and inferred low intrinsic rate of population increase suggests that this skate will be highly sensitive to exploitation. Two genetically distinct subpopulations exist in the Mediterranean Sea and Northeast Atlantic. In the Northeast Atlantic, the depth range of this species extends down the continental slope to 900 m, but it is rarely encountered on the outer continental shelves. There are limited data on occurrence in Norwegian waters, the Faroes Grounds and the French and Iberian Atlantic shelves but nothing is known of current population trends in the Northeast Atlantic region. Historically, this species may have been more widely distributed in shelf areas.

In the Mediterranean Sea, this species is found at depths > 200 m and is most frequently captured at depths of 200500 m in research surveys. It is moderately abundant in the central and eastern Mediterranean Sea, but is now absent from the west. While there has been no indication of a decline in abundance for the last 20 years in Italian waters, it has been absent from research surveys from the Gulf of Lions since 1984 and it is now rarely captured in the shelf areas of the Adriatic Sea.

The species is assessed as Near Threatened as, considering the status of otherDipturusspecies in the European region, the low catch levels in surveys and fisheries and the slow life history of the species,D. oxyrinchusis suspected to have declined by nearly 30% over the past 30 years (three-generation span), therefore being close to qualify as threatened under criterion A2bd. Further research is required to understand the taxonomic and population status of this species in both areas and management and monitoring are required.


History
  • 2007
    Near Threatened (NT)
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

Population

Population

Two genetically distinct subpopulations exist in the Mediterranean Sea and the Northeast Atlantic.

Northeast Atlantic

Little is known of the subpopulation status or trends in abundance in the Northeast Atlantic, but it is suspected to have declined or contracted in range. Between the late 1960s and 2002 United Kingdom groundfish surveys occasionally reported this species in the northern North Sea and Celtic Sea at depths of 111159 m. Catch rates over this time period were very low ranging between 0.01 and 0.11 individuals captured per hour of trawling (Ellis et al. 2005). In the Annual Autumn Bottom Trawl Surveys of the northern Norwegian Coast, 54 individuals were reported in 1994, and only two individuals were reported in 2005 (Williams et al. 2008). Along the northern coast of Norway from 19922005, Williams et al. (2008) caught a mean of 7.7 individuals per square kilometre. The catches in this study were relatively high, indicating that although the species is somewhat rare, local aggregations may occur. In and around the Bay of Biscay catches showed large fluctuations, ranging from zero tonnes in 1999, to 16 tonnes in 2002, and decreasing again to zero tonnes in 2010 (ICES 2012). Although information is limited, the sensitive life history characteristics and available data suggest that this subpopulation is declining in Northeast Atlantic waters.

Mediterranean Sea

In the Mediterranean, the International Trawl Survey in the Mediterranean (MEDITS) preformed 6,336 tows between 1994 and 1999 over the entire European Mediterranean area and Morocco at a depth of 10800 m. This species was the second most abundant skate in this survey and was recorded in 3% of hauls in this area. It was found at depths ranging from 50 to 800 m, but was caught most frequently between 200 and 500 m in the western central Mediterranean Sea and eastwards in the Aegean Sea (Baino et al. 2001, Serena 2005, Serena et al. 2010). A longline survey in 2004 confirmed the presence of this species in the southeast Aegean Sea, around Rhodes between 300 and 400 m depth (Corsini-Foka 2009). This species was historically present in the Gulf of Lions, northwest Mediterranean Sea, where it was captured in 10% (n=27) of hauls, occurring between 1959 and 1972 (coast to 150 m depth) and was also present in the catches of surveys performed between 19801984. It was subsequently absent from 628 scientific tows done in the same area in the period 19851995 (Aldebert 1997). Similarly, in the Adriatic Sea, historical trawl surveys from 1948 showed that this species was present in 3.2% of hauls carried out on the continental shelf, while in a comparable MEDITS survey in 1998 reported that this species was absent from all hauls on the continental shelf (Jukic-Peladic et al. 2001). In the south Ligurian and north Tyrrhenian Seas this species has been found at depths ranging from 164750 m, and was mostly concentrated on the outer margin of the slope from 300400 m. Over this survey period, biomass has reportedly decreased while abundance remained stable. This suggests a change in population structure, with an increasing presence of juveniles in catches. Given the sensitive life history characteristics, evidence of significant population declines and apparent disappearance in some localised areas (likely due to fisheries pressure), this subpopulation is considered to be decreasing throughout the Mediterranean Sea.

Considering the status of otherDipturusspecies in the European region,D. oxyrinchusis also inferred to be in decline, although to a lesser extent due to its smaller size, and it is suspected that the species has declined by nearly 30% over the past 30 years (three-generation span).


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

This is one of the larger bodied species of skate and it is thought to have declined from shelf areas, although this would be the shallower fringe of the bathymetric distribution. The large body size (150 cm), and presumably slow growth and later maturation and likely low intrinsic rate of population increase of this species render it especially vulnerable to exploitation such as trawling and at risk of local extinction (Walker and Hislop 1998, Dulvy et al. 2000, Dulvy and Reynolds 2002).

Northeast Atlantic

There are no specific data available on threats, however it is inferred that, similar to other large-bodied skates, this species may be retained as bycatch in demersal trawl and longline fisheries, particularly in deeper waters. Although only large individuals may be landed for consumption, most size classes are likely to be taken in fishing nets. This species is caught and landed from offshore fisheries as reported by the United Kingdom, but data are unreliable. These landings are likely the result of misidentification or incorrect use of species codes (ICES 2012). Given recent restrictions on landing other members of this genus, recent data indicating increasing catches of this skate are questionable due to possible reporting of other species as Longnosed Skate (Dipturus oxyrinchus; ICES 2013).

Mediterranean Sea

This skate is captured as bycatch in bottom trawl fisheries targeting Norway Lobster (Nephrops norvegicus) or Red Shrimp (Aristeus antennatus) and by offshore bottom longlines. Over the last 50 years, trawl effort has increased numerically and technologically in the shelf and slope area of the Mediterranean Sea. For example, the Gulf of Lions area was historically exploited by small-scale benthic trawl fisheries composed of 27 small, low-powered boats with a total of 2,700 horse power (hp), between 1974 and 1987 effort has increased to a total of 19,940 hp. In particular, fishing effort targeting small pelagic fish has increased (Aldebert 1997). The Adriatic Sea is subject to trawling by Italian, Croatian, Slovenian, and Albanian fleets, however, no landings data are available (Jukic-Peladic et al. 2001). The General Fisheries Commission for the Mediterranean (GFCM), the main intergovernmental decision-making body on fishery management in the Mediterranean Sea, has made the decision to refrain from expanding deepwater fishing operations beyond the limit of 1,000 m. However this species occurs mostly from 200-500 m, thus deepwater fisheries development within the depth range of this species remains a cause for concern.

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)
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

Management

Conservation Actions

Conservation Actions

In 1999, the European Union (EU) introduced a Total Allowable Catch (TAC) for skates and rays of 6,060 tonnes (t) for fisheries operating in the Norwegian Sea (International Council for the Exploration of the Sea [ICES] Division IIa) and North Sea (ICES sub-area IV) based on landing statistics from the previous five years. This TAC has been progressively reduced by 825% annually to the current level of 1,256 t. As part of the TAC, the bycatch quota for vessels over 15 meters was set at 25% of live weight of catch retained on board per trip. For much of this period (19992014), the TAC was higher than reported landings and therefore not effectively constraining catches.

Skate and ray TACs were established for other EU waters in 2009, including the Skagerrak and Kattegat (ICES Division IIIa) and from the northwest coast of Scotland and North Ireland to Portuguese waters (ICES sub-areas VIIX). These TACs have also been gradually reduced since then. In 2013, the TAC for all skate and ray species grouped was 21,800 tonnes (regulations are available online at http://faolex.fao.org).

Further research should be conducted on the population size and trend of the species.

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

Relevance to Humans and Ecosystems

Benefits

Importance

fisheries: minor commercial; price category: medium; price reliability: reliable: based on ex-vessel price for this species
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

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!