Zoological Studies

Vol. 59, 2020

(update: 2020.08.01)

Somniosus (Rhinoscymnus) cheni sp. nov., A New Species of Sleeper Shark (Squaliformes: Somniosidae) from Eastern Taiwan, with Aspects of Embryo Biology

Hua-Hsun Hsu1, Chia-Yen Lin2,3, and Shoou-Jeng Joung2,3,*


1Marine Studies Section, Center for Environment and Water, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. E-mail: hsuhuahsun@yahoo.com.tw (Hsu)
2Department of Environmental Biology and Fisheries Science, National Taiwan Ocean University, Keelung 20224, Taiwan.
E-mail: kinomotohiko@gmail.com (Lin)
3George Chen Shark Research Center, National Taiwan Ocean University, Keelung 20224, Taiwan. *Correspondence: E-mail: f0010@ntou.edu.tw (Joung). Tel: +886-2-24622192 ext. 5039

(Received 3 June 2019 / Accepted 28 July 2020)
Communicated by Hin-Kiu Mok

A new species of sleeper shark is described on the basis of a 134.0 cm total length pregnant female collected from off Hualien, eastern Taiwan. The species belongs to the small species group (subgenus Rhinoscymnus) and can be distinguished from its congeners in having a smaller second dorsal fin, smaller eyes, more tooth rows in the upper jaw, less in the lower jaw, and different body proportion. Moreover, the specimens has 33 embryos which is clearly more than the two other small species in the subgenus. Information of embryo biology are provided as well.

Key words: Elasmobranch, Litter size, Morphology, Sex-bias, Taxonomy.

Citation: Hsu HH, Lin CY, Joung SJ. 2020. Somniosus (Rhinoscymnus) cheni sp. nov., a new species of sleeper shark (Squaliformes: Somniosidae) from eastern Taiwan, with aspects of embryo biology. Zool Stud 59:0gg. doi:-.