The Japanese topeshark (Hemitriakis japanica) is a species of shark belonging to the family Triakidae. It can reach a length of up to 3.9 feet. It is found in the subtropical northwest Pacific from China, Taiwan, Korea, and Japan. It has distinctive white edged fins and small slit like eyes.
Family: Triakidae – Houndsharks
Genus: Hemitriakis
Species: japanica
Phylum– Chordata
Class– Chondrichthyles
Common Name– Ground Sharks
Family– Triakidae
Common Name– Houndsharks
Genus– Hemitriakis
Species– japanica
Status: IUCN Red List LEAST CONCERN
Average Size and Length: They are born around 20 cm/7.8 inches. Mature males have been measured around 85 cm/2.8 feet. Mature females have been measured between 80-100 cm/2.6-3.3 feet. The maximum recorded for a male has been 110 cm/3.6 feet, and over 120 cm/3.9 feet for a female.
Teeth and Jaw: The mouth is broadly arched. The teeth are small and blade like, with the main cusp angled with inward serrations.
Head: The snout is moderately long and parabolic. There are short anterior nasal flaps. The eyes are fairly low and slit-like just above ridges.
Tail: The tail is elongated.
Demographic, Distribution, Habitat, Environment and Range: The Japanese topeshark can be found in the west Pacific in China, including Taiwan, Korea and Japan in temperate to subtropical seas on the continental shelf close inshore to more than 328 feet offshore (40° N and 21° N, 119°E and 177°E). They have been recorded between 66-1,132 feet and are considered demersal.
Aesthetic Identification: The Japanese topeshark is thin and silver grey in color. There are conspicuous white edges on the fins. The fins are not strongly falcate in adults. The first dorsal fin origin is over or behind the pectoral free rear tips (except for in newborns). The anal fin is much smaller than the dorsal fins.
Biology and Reproduction: They are ovoviviparous, no yolk-sac placenta. They have 8-22 pups per litter with an average of 10. The litter size increases with the size of the female. In the East China Sea, mating occurs from June to September (but mostly June-August) and pupping in June and August (but mostly June). They are said to live up to 15 years of age.
Behavioral Traits, Sensing and Intelligence: Unknown.
Japanese Topeshark Future and Conservation: They are currently of least concern. They are a common bycatch and have been used for human consumption.
Japanese Topeshark Recorded Attacks on Humans: Not a threat to humans.