Hokkaido skate

📖 Overview

Oviparous. Distinct pairing with embrace. Young may tend to follow large objects, such as their mother . Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats . Egg capsules are 12.0 cm long and 9.0 cm wide .

🔬 Taxonomy

🐟 Physical Description

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) .: other.

🌀 Behaviour

Behavioural data for Hokkaido skate is currently being reviewed.

🦐 Diet

🥚 Reproduction

Oviparous, paired eggs are laid. Embryos feed solely on yolk . Distinct pairing with embrace. Young may tend to follow large objects, such as their mother . Eggs have horn-like projections on the shell .

🌍 Habitat & Distribution

Marine; demersal; depth range 96 - 540 m . Temperate Northwest Pacific: off northern Japan.

🌿 Ecology

📐 Morphometrics

🌡️ Water Parameters & Tolerance

📊 Population Risk & Fisheries

🐠 Related Species

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