Flapper skate (Dipturus batis)

Also known as: Blue skate, common skate, grey skate
  
French: Flotte, Pocheteau Gris, Pochette
Spanish: Noriega, Raya Noruega
KingdomAnimalia
PhylumChordata
ClassChondrichthyes
OrderRajiformes
FamilyRajidae
GenusDipturus (1)
SizeMale length: up to 205 cm (2)
Female length: up to 285 cm (2)

The flapper skate is classified as Critically Endangered (CR) on the IUCN Red List (1).

The flapper skate (Dipturus batis) is the largest European ray (1). The undersurface is dark grey with black spots or stripes and the uppersurface is more of a greenish brown colour (3), often with lighter mottling (5). The snout is pointed and the flattened body has a rhombic shape with sharp corners (4), and slightly concave outer edges to the wings (3). There is a row of 12 to 18 thorns along the tail (4).

The flapper skate is found in the eastern Atlantic Ocean from Madeira and northern Morocco, north to Iceland and Norway. Despite its widespread distribution, this species is extremely scarce in European waters and may already have disappeared from the Irish Sea (2).

The flapper skate occurs over firm ground in coastal shelf waters (3), from depths down to 200 metres and occasionally as deep as 600 metres (2).

The flapper skate is often seen travelling in same sex/age groups (3), near to the sea floor (4). Mating occurs mainly in the spring and during copulation there is a distinct embrace between males and females (4). The female then lays long oblong egg capsules, which are anchored into the muddy or sandy substrate by their stiff pointed horns (4). An individual will lay around 40 eggs a year (4). Males only reach sexual maturity once they have reached a length of 125 centimetres, which corresponds to around 10 years of age (2). The flapper skate is thought to live for as long as 50 years (2), and it takes around 14 years for the population to double in size (4).

Flapper skates feed on a variety of bottom dwelling organisms but preferentially consume fish (4). Unlike most other skates, these fish are active by both day and night (5).

Flapper skates are long-lived and slow to mature, factors that make them particularly vulnerable to both direct and accidental targeting by the fishing industry (2). During the mid 20th Century, skates and rays made up a considerable amount of commercial fishing in the United Kingdom (6). The population of flapper skates has seen a drastic decline in European waters following this intensive fishing pressure. Although no longer targeted in the majority of areas, as the population is too low, these fish are still threatened by fisheries bycatch (2).

Further research on the distribution of the species and the monitoring of life-cycles, growth and so on will also need to be undertaken in order to successfully manage the recovery of this fish (2).

Find out more about the flapper skate:

Further information on the conservation of sharks and rays:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (May, 2006)
    http://www.redlist.org
  2. UK BAP (August, 2002)
    http://www.ukbap.org.uk
  3. The Marine Life Information Network for Britain and Ireland (MarLIN) (August, 2002)
    http://www.marlin.ac.uk
  4. Burnie, D. (2001) Animal. Dorling Kindersley, London.
  5. Fishbase (August, 2002)
    http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=2058&genusname=Dipturus&speciesname=batis
  6. Shark Trust (August, 2002)
    http://www.sharktrust.org/