You can sponsor this page

Arctoraja simoterus (Ishiyama, 1967)

Hokkaido skate
Upload your photos and videos
Google image
Image of Arctoraja simoterus (Hokkaido skate)
No image available for this species;
drawing shows typical species in Arhynchobatidae.

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

Elasmobranchii (sharks and rays) > Rajiformes (Skates and rays) > Arhynchobatidae (Softnose skates)
Etymology: simoterus: Name probably derived from the comparative tense of the Greek σιμóς, meaning 'pug-nosed', referring to its rounded snout (Ref. 89865).

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

Marine; demersal; depth range 96 - 540 m (Ref. 89865). Temperate

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

Northwest Pacific: off northern Japan.

Size / Weight / Age

Maturity: Lm ?  range ? - ? cm
Max length : 101 cm TL male/unsexed; (Ref. 89865)

Short description Identification keys | Morphology | Morphometrics

This species is distinguished from all other members of the subgenus Arctoraja by having a complete row of dorsal thorns, narrow interdorsal space, high count of precaudal vertebrae, and COI haplotype. It is further distinguished from B. parmifera by its narrower interdorsal space 0.5-1.0% TL (vs. 1.0-3.9% TL), number of precaudal and caudal vertebrae 41 and 90 (vs. 32-40 and 82-89), tail thorns 22-28 (vs. 15-23), larger orbit 4.3-5.3% TL (vs. 2.6-4.8% TL), 3 postdorsal foramina slightly smaller posteriorly, posteriormost postventral foramina 4 times larger than preceding 6 foramina (vs. anterior- and posterior-most postdorsal and postventral foramina of the scapulacoracoid larger than 3 intervening foramina), distal projection of the ventral marginal directed distally (vs. distolaterally), ventral terminal lanceolate (vs. tear-drop shaped), dorsal and ventral marginals extending farther distally to distal tip of dorsal terminal 3 (vs. extending to about a quarter the length of dorsal terminal 2); from B. panthera by its narrow interdorsal space width (vs. 1.4-3.1% TL); anterior portion of body shorter and narrower (vs. longer and wider); tail shorter (vs. longer); posterior fontanelle narrowly elongate (vs. pear-shaped); internal carotid foramina widely separated (vs. foramina in a single median pit), foramen of scapulocoracoid all large (vs. anterior postdorsal foramen large, others much smaller), ventral terminal lanceolate (vs. tear-drop shaped); from the incompletely thorned B. smirnovi by its higher number of vertebrae 131 (vs. 118-127), more precaudal vertebrae 41 (vs. 31-38), smaller mouth size 8.1-9.1% TL (vs. 8.3-11.6% TL), neurocranium with 2 fontanelles (vs. 1), internal carotid foramina widely separated (vs. close together in a single pit), scapulocoracoid with 3 foramina, more posterior each slightly smaller (vs. 5 foramina, anterior- and posteriormost larger than three intermediates), and pelvic girdle with two obturator foramina widely spaced (vs. close together) (Ref. 89865).

Biology     Glossary (e.g. epibenthic)

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 12.0 cm long and 9.0 cm wide (Ref. 41253).

Life cycle and mating behavior Maturities | Reproduction | Spawnings | Egg(s) | Fecundities | Larvae

Oviparous, 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). Eggs have horn-like projections on the shell (Ref. 205).

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)


CITES

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

  Harmless





Human uses

FAO - Publication: search | FishSource |

More information

Trophic ecology
Food items
Diet compositions
Food consumptions
Food rations
Predators
Ecology
Ecology
Population dynamics
Growths
Max. ages / sizes
Length-weight rel.
Length-length rel.
Length-frequencies
Mass conversions
Recruitments
Abundances
Life cycle
Reproduction
Maturities
Fecundities
Spawnings
Spawning aggregations
Egg(s)
Egg developments
Larvae
Larval dynamics
Distribution
Countries
FAO areas
Ecosystems
Occurrences
Introductions
BRUVS - Videos
Anatomy
Gill areas
Brains
Otoliths
Physiology
Body compositions
Nutrients
Oxygen consumptions
Swimming type
Swimming speeds
Visual pigment(s)
Fish sounds
Diseases / Parasites
Toxicities (LC50s)
Genetics
Genetics
Electrophoreses
Heritabilities
Human related
Aquaculture systems
Aquaculture profiles
Strains
Ciguatera cases
Stamps, coins, misc.
Outreach
Collaborators
Taxonomy
Common names
Synonyms
Morphology
Morphometrics
Pictures
References
References

Tools

Special reports

Download XML

Internet sources

AFORO (otoliths) | Aquatic Commons | BHL | Cloffa | BOLDSystems | Websites from users | Check FishWatcher | CISTI | Catalog of Fishes: genus, species | DiscoverLife | ECOTOX | FAO - Publication: search | Faunafri | Fishipedia | Fishtrace | GenBank: genome, nucleotide | GloBI | Google Books | Google Scholar | Google | IGFA World Record | MitoFish | Otolith Atlas of Taiwan Fishes | PubMed | Reef Life Survey | Socotra Atlas | Tree of Life | Wikipedia: Go, Search | World Records Freshwater Fishing | Zoological Record

Estimates based on models

Preferred temperature (Ref. 123201): 1 - 17.6, mean 11.8 °C (based on 33 cells).
Phylogenetic diversity index (Ref. 82804):  PD50 = 0.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00513 (0.00253 - 0.01042), b=3.12 (2.95 - 3.29), in cm total length, based on LWR estimates for this Genus-body shape (Ref. 93245).
Trophic level (Ref. 69278):  3.9   ±0.7 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):  High vulnerability (61 of 100).