Environment: milieu / climate zone / depth range / distribution range
Marine; demersal. Temperate
Northwest Pacific: Japan and the Ryukyu Islands to the East China Sea.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 40.0 cm TL male/unsexed; (Ref. 12951)
Found on sand and rock bottoms (Ref. 12951, 11230). Ovoviviparous, with up to 4 in a litter (Ref. 12951).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Male grasps pectoral fin of female then mounts on rear margin of female's dorsum during copulation. Copulation reported to last up to 14 minutes.
Mould, B., 1994. A world list of rays. The scientific nomenclature and distribution of the recent Batoidea (Batoidea, Elasmobranchii, Chondrichthyes). University of Nottingham, [UK]. 82 p. (Ref. 8630)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.5 ±0.37 se; Based on food items.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Assuming fecundity<100).
Vulnerability (Ref. 59153
): High vulnerability (62 of 100) .