The Taiwan spurdog (''Squalus formosus'') is a species of

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

in the genus ''

Squalus ''Squalus'' is a genus of dogfish sharks in the family Squalidae. Commonly known as spurdogs, these sharks are characterized by smooth dorsal fin spines, teeth in upper and lower jaws similar in size, caudal peduncle with lateral keels; upper ...

''. It was accidentally found in

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northe ...

's Tashi fish market by

William Toby White William Toby White is an Australian ichthyologist. He studies speciation and biodiversity of shark, ray, and skate species (subclass Elasmobranchii) through morphological and molecular systematics. Education White received bachelor's (1997) ...

and a colleague of the

CSIRO The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an Australian Government agency responsible for scientific research. CSIRO works with leading organisations around the world. From its headquarters in Canberra, CSIRO ...

Hobart, Australia Hobart ( ; Nuennonne/Palawa kani: ''nipaluna'') is the capital and most populous city of the Australian island state of Tasmania. Home to almost half of all Tasmanians, it is the least-populated Australian state capital city, and second-smalle ...

. They named it ''S. formosus'' ("Formosa" being a former name for Taiwan). It has also be recorded from the coast of Japan, near

Kyushu is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surroun ...

and

Shikoku is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), ...

. Sharks now identified as ''Squalus formosus'' had earlier been classified as ''

Squalus blainville The longnose spurdog (''Squalus blainville'') is a dogfish shark of the genus ''Squalus'', found over continental shelves A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a ...

'', a species that is no longer considered to occur in Taiwan. ''Squalus formosus'' can be morphologically separated from other three ''

'' species found in Taiwanese waters (which are '' S. brevirostris'', '' S. japonicus'' and '' S. mitsukurii''); it is morphologically more similar to ''

Squalus albifrons ''Squalus albifrons'', the eastern highfin spurdog, is a dogfish described in 2007. It is a member of the family Squalidae, found on the continental shelf off Queensland, Australia, at depths between 220 and 510 m. The length of the longest spec ...

'' from eastern Australia than the other Taiwanese species. Similarly, genetic methods identify ''S. albifrons'' as the closest relative of ''S. formosus''. It is a medium-sized species of ''

'' that can reach at least TL.

References

Squalus Fish of Japan Fish of Taiwan Fish of the Pacific Ocean Fish described in 2011 Taxa named by William Toby White {{Shark-stub