Shortspine Spurdog

About the Shortspine Spurdog

The shortspine spurdog is a dogfish species found around the world on continental shelves in temperate and subtropical oceans, at depths of 0 to 950 m/0 to 3,116.8 ft. Squalus mitsukurii was once considered a globally distributed species, but recent morphological and genetic work suggests the species is restricted to temperate waters of Japan and Korea, and is possibly endemic to the Northwest Pacific (Pfleger et al. 2018, Ziadi-Künzli et al. 2020). The resolution of the species-complex is ongoing with further species likely being described in the future.

These sharks have smooth spines on their dorsal fins. They usually grow up to 76 cm/2 ft 5.9 in in length. Since they’re so widespread, they have several separate populations that mature at different rates. The Japanese population grows the largest, with females often reaching 125 cm/4 ft 1.2 in in length. They can live up to 27 years. Ovoviviparous, which means animals that develop inside eggs that hatch inside the mother’s body, leading to a live birth.

Since the populations are fragmented, it’s possible that they have become separate species. This uncertainty makes it impossible to determine population health.

The species is likely to be caught incidentally in demersal trawl, longline, and gillnet fisheries across its entire range and is likely utilized for its liver oil, flesh, and fish meal. There is high spatial overlap with intensive fishing pressure, suspected declines in part of its range (China, Philippines) but estimated increasing population in Japan, and a lack of species-specific management across its entire range. The Shortpine Spurdog is suspected to have undergone a population reduction of 50–79% over the past three generations (62 years) based on actual levels of exploitation, and it is assessed as Endangered A2bd.There are no species-specific measures in place for the Shortspine Spurdog. Further information is required on its distribution, ecology and life history, as well as interactions with local fisheries.

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Shortspine Spurdog Gallery