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Rajella ravidula (Hulley, 1970)

Smoothback skate
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Native range | All suitable habitat | Point map | Year 2050
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Rajella ravidula   AquaMaps   Data sources: GBIF OBIS
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Image of Rajella ravidula (Smoothback skate)
No image available for this species;
drawing shows typical species in Rajidae.

Namibia country information

Common names: Rog, Skate
Occurrence: native
Salinity: marine
Abundance: | Ref:
Importance: of no interest | Ref: Bianchi, G., K.E. Carpenter, J.-P. Roux, F.J. Molloy, D. Boyer and H.J. Boyer, 1999
Aquaculture: | Ref:
Regulations: | Ref:
Uses: no uses
Comments: Ranges from Lüderitz southward. Common in central Namibia (Ref. 36731). Incidentally caught in bottom trawl (Ref. 36731). A bycatch of the deep-water fishery (Ref. 36731). Also Ref. 2708, 5578, 11228, 54854.
National Checklist:
Country Information: https://www.cia.gov/library/publications/resources/the-world-factbook/geos/wa.html
National Fisheries Authority: http://www.benefit.org.na/
Occurrences: Occurrences Point map
Main Ref: Bianchi, G., K.E. Carpenter, J.-P. Roux, F.J. Molloy, D. Boyer and H.J. Boyer, 1999
National Database:

Common names from other countries

Skate, Gladrugrog, Hallikas väikerai, ... more

Classification / Names Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa

Elasmobranchii (sharks and rays) > Rajiformes (Skates and rays) > Rajidae (Skates)
Etymology: Rajella: Latin, raja, -ae = a sting ray (Raja sp.) (Ref. 45335).

Environment: milieu / climate zone / depth range / distribution range Ecology

Marine; bathydemersal; depth range 496 - 1477 m (Ref. 106604).   Deep-water

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Southeast Atlantic: known only from the three type specimens collected from off the west coast of South Africa and one record from off Morocco.

Size / Weight / Age

Maturity: Lm ?  range ? - ? cm
Max length : 79.2 cm TL male/unsexed; (Ref. 106604)

Short description Morphology | Morphometrics

Long snout, small eyes, and a thick disc; tail about as long as body; moderate-sized conspicuous light thorns in 2 prominent rows from shoulders to 1st dorsal fin, no or few mid-dorsal thorns, and no thorns on snout (Ref. 5578). Medium grey to purplish-brown dorsally, white ventrally but dusky on disc margins, around vent and on underside of tail (Ref. 5578).

Biology     Glossary (e.g. epibenthic)

Inhabits the upper slope (Ref. 5578). Minimum depth reported taken from Ref. 5578. Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205).

Life cycle and mating behavior Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae

Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449).

Main reference Upload your references | References | Coordinator : McEachran, John | Collaborators

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)

IUCN Red List Status (Ref. 130435)

  Least Concern (LC) ; Date assessed: 24 April 2018

CITES (Ref. 128078)

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

  Harmless




Human uses

FAO(Publication : search) | FishSource |

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Internet sources

Aquatic Commons | BHL | Cloffa | Websites from users | Check FishWatcher | CISTI | Catalog of Fishes(genus, species) | DiscoverLife | ECOTOX | Faunafri | Fishtrace | GenBank(genome, nucleotide) | GloBI | GOBASE | | Google Books | Google Scholar | Google | IGFA World Record | MitoFish | Otolith Atlas of Taiwan Fishes | PubMed | Reef Life Survey | Scirus | SeaLifeBase | Tree of Life | Wikipedia(Go, Search) | World Records Freshwater Fishing | Zoological Record

Estimates based on models

Preferred temperature (Ref. 115969): 3.8 - 7.9, mean 6 (based on 59 cells).
Phylogenetic diversity index (Ref. 82804):  PD50 = 0.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00302 (0.00141 - 0.00645), b=3.24 (3.07 - 3.41), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245).
Trophic level (Ref. 69278):  3.7   ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref. 120179):  Low, minimum population doubling time 4.5 - 14 years (Fec assumed to be <100).
Fishing Vulnerability (Ref. 59153):  Moderate to high vulnerability (52 of 100).