Studies on Sharks―XVI Age and Growth of Eiraku Shark Galeorhinus japonicus (MÜLLER et HENLE)
Year: 1978
Type: article
Abstract: Age and growth of Eiraku shark Galeorhinus japonicus which was collected from September 1972 to October 1976 at the western waters of Kyushu were studied by means of reading the rings of the vertebral centrum. The transparent zone is formed between autumn and early spring while the opaque zone between spring and summer. The maximum number of ring was 10 in male and 14 in female. The relationship between centrum radius R (mm) and total length L (mm) is indicated by the following equations: Male : log R=1.0366 log L+0.2736 Female : log R=1.3467 log L-0.6335. The von Bertalanffy growth equations in both sexes are: Male : Lt=1111{1-exp〔-0.2435(t+0.9995)〕} Female : Lt=1321{1-exp〔-0.2005(t+1.0000)〕}, where Lt=total length in mm at age t t=time in years. Accordingly, the growth rate of female of this species is faster than male, and the total length of male at 10 years old attains 1035mm and female 1175mm. The sexual maturity of this species is about 5 years old in both sexes.
Authors: S. Tanaka, Che-Tsung Chen, Kazuhiro Mizue
Language: English
Subfield: Nature and Landscape Conservation
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W11088255