Elasmobranchii (sharks and rays) > Rajiformes
(Skates and rays) > Arhynchobatidae
Etymology: Bathyraja: Greek, bathys = deep + Latin, raja, -ae = a ray (Raja sp) (Ref. 45335); kincaidii: Named after Professor Trevor Kincaid from the University of Washington (Ref. 6885).
Environment: milieu / climate zone / depth range / distribution range
Marine; bathydemersal; depth range 119 - 1372 m (Ref. 126515). Temperate
North Pacific: Canada (British Columbia) south to Baja California, Mexico. Possibly up to Alaska (may be confused with Bathyraja interrupta), but this northern extent cannot be verified.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 62.0 cm TL male/unsexed; (Ref. 126515); 58.0 cm TL (female); max. reported age: 18 years (Ref. 126515)
Morphology | Morphometrics
This small and rounded skate (max 56.0 cm TL), with short disc length (29.0-54.1% TL), width (61.2-67.3% TL), head length (15.9-21.3% TL), and internarial distance (5.2-6.7% TL); claspers are long and thin, rounded tip not bulbous, no pseudosiphon, with an average pseudorhipidion and not conspicuously projecting from the tip, V-shaped cleft, has a projection and an average sentina, projection is pointed; teeth in 22-31 rows on upper jaw and 18-31 rows on lower jaw; pectoral radials 69-72; pelvic fins17-22; total vertebrae 132; dorsal surface covered in uniform prickles; thorns present on dorsal surface, males with well-developed alar thorns, no malar thorns, middorsal thorns range in number (0-9), nuchal thorns strong (3-7), tail thorns few (14-22), scapular vary in count (0-2), interdorsal thorns weak or obsolete (0-2), thorns in a continuous row. Colouration: dorsal mottled brown to grey, with numerous small dark spots; ventral coloration white, usually with dark brown blotches on underside of tail (Ref. 126515).
Common on the continental shelf-slope break. Inhabits deep waters where inidividuals are usually in deeper waters at the southern edge of distribution. Reported to feed on invertebrates (euphausiids, polychaetes, amphipods, crabs, and mysids). Size at maturity for males 44 cm TL and 45 cm TL for females, where males grow to 62 cm TL and females to 58 cm TL; size at birth is 12-16 cm TL. Estimated maximum age for females 17 years and for males 18 years, Egg cases are very small (5.0-6.6 cm TL), colour light to dark brown, with dorsal surface covered with fine fibers, while ventral with either a thin fibrous layer or without. The egg cases reported to have long, inward bending horns at each corner and strong lateral keels, the horns flattening and becoming thread-like at the tips (Ref. 126515).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Knuckey, J.D.S. and D.A. Ebert, 2022. A taxonomic revision of Northeast Pacific softnose skates (Rajiformes: Arhynchobatidae: Bathyraja Ishiyama). Zootaxa 5142(1):1-89. (Ref. 126515)
IUCN Red List Status (Ref. 126983)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= No PD50 data [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00603 (0.00319 - 0.01139), b=3.11 (2.95 - 3.27), in cm total length, based on LWR estimates for this Genus-BS (Ref. 93245
Trophic level (Ref. 69278
): 3.9 ±0.7 se; based on size and trophs of closest relatives
Generation time: 6.6 ( na - na) years. Estimated as median ln(3)/K based on 2 growth studies.
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): Moderate vulnerability (45 of 100).