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Dipturus batis  (Linnaeus, 1758)

Blue skate
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Dipturus batis
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Norway country information

Common names: Glattrokke, Glattskate, Storskate
Occurrence: native
Salinity: marine
Abundance: | Ref:
Importance: | Ref:
Aquaculture: | Ref:
Regulations: | Ref:
Uses: no uses
Comments:
National Checklist:
Country Information: httpss://www.cia.gov/library/publications/resources/the-world-factbook/geos/no.html
National Fisheries Authority: https://odin.dep.no/fid/eng/
Occurrences: Occurrences Point map
Main Ref: Muus, B. and P. Dahlström, 1978
National Database:

Classification / Names

Elasmobranchii (sharks and rays) > Rajiformes (Skates and rays) > Rajidae (Skates)
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL

Common names from other countries

Issue
Raja macrorynchus Rafinesque, 1810 is considered as valid in Eschmeyer (Eschmeyer (CofF ver. Sep. 2011: Ref. 88002): Ref. 88002), although many authors put it in (questionable) synonymy with R. batis Linnaeus, 1758.

Main reference

Size / Weight / Age

Max length : 285 cm TL male/unsexed; (Ref. 35388); common length : 100.0 cm TL male/unsexed; (Ref. 3261); max. published weight: 97.1 kg (Ref. 40637)

Length at first maturity
Lm 160.0  range ? - ? cm

Environment

Marine; demersal; depth range 100 - 1000 m (Ref. 4426), usually 100 - 200 m (Ref. 4426)

Climate / Range

Subtropical, preferred 19°C (Ref. 107945); 69°N - 12°N, 30°W - 42°E

Distribution

Eastern Atlantic: Norway, Iceland, the Faroes to Senegal, including western Mediterranean and western part of the Baltic. Extirpated by trawling from much of its former range (Ref. 27438).
Countries | FAO areas | Ecosystems | Occurrences | Introductions

Short description

Dorsal spines (total): 0; Anal spines: 0; Anal soft rays: 0. Snout very long and pointed; length before eyes 2,5-4,0 times distance between them; disc broadly rhombic with acute outer corners; upper surface and underside smooth in young, partly prickly in larger specimens; no thorns on disc, a row of 12-18 thorns along tail; 40-56 tooth rows; upper surface olive-grey or brown with a variable pattern of light spots, underside ashy-grey to blue-grey (Ref. 3167).

Biology     Glossary (e.g. epibenthic)

Benthic species in shelf and slope waters with a wide tolerance for depth and temperature (Ref. 4426). Found in coastal waters mainly within the 200 m range (Ref. 3167). Feed on all kinds of bottom animals, large individuals prefer fish (Ref. 3167). Oviparous. Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (Ref. 205). Mate in spring and the egg capsules are laid during the summer. Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats (Ref. 205). Egg capsules are 10.6-24.5 cm long and 5.0-14.5 cm wide (Ref. 41250). About 40 eggs per individual are laid annually (Ref. 41250). Flesh is marketed fresh or smoked (Ref. 35388).

IUCN Red List Status (Ref. 115185)

  Critically Endangered (CR) (A2bcd+4bcd)

Threat to humans

  Harmless



Human uses

Fisheries: minor commercial; gamefish: yes

More information

Common names
Synonyms
Metabolism
Predators
Ecotoxicology
Reproduction
Maturity
Spawning
Fecundity
Eggs
Egg development
Age/Size
Growth
Length-weight
Length-length
Length-frequencies
Morphometrics
Morphology
Larvae
Larval dynamics
Recruitment
Abundance
References
Aquaculture
Aquaculture profile
Strains
Genetics
Allele frequencies
Heritability
Diseases
Processing
Mass conversion
Collaborators
Pictures
Stamps, Coins
Sounds
Ciguatera
Speed
Swim. type
Gill area
Otoliths
Brains
Vision

Tools

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Internet sources

Estimates of some properties based on models

Phylogenetic diversity index (Ref. 82805)
PD50 = 0.5000 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Trophic Level (Ref. 69278)
3.5   ±0.6 se; Based on diet studies.

Resilience (Ref. 69278)
Very Low, minimum population doubling time more than 14 years (K=0.06; tm=11; tmax=51)

Vulnerability (Ref. 59153)
Very high vulnerability (86 of 100)
Price category (Ref. 80766)
Medium