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Vol. 44 No. 1, 2005
Age, Growth, and Reproduction of the Spinner Shark, Carcharhinus brevipinna, in the Northeastern Waters of Taiwan
Shoou-Jeng Joung1, Yih-Yia Liao2, Kwang-Ming Liu3,*, Che-Tsung Chen1,4, and Len-Chi Leu1
1Department
of Environmental Biology and Fisheries Science, National Taiwan Ocean
University, 2 Pei-Ning Road, Keelung, Taiwan 202
2Department
of Tourism Management, Shih Chien University Kaohsiung Campus, 200
University Road, Neiman, Kaohsiung County, Taiwan 845
3Institute of Marine Resource Management, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, Taiwan 202
4Department of Fisheries, National Kaohsiung Marine University, 142 Haitsuan Rd., Kaohsiung, Taiwan 811
Shoou-Jeng Joung, Yih-Yia Liao, Kwang-Ming Liu, Che-Tsung Chen, and Len-Chi Leu (2005) Age, growth, and reproduction of the spinner shark, Carcharhinus brevipinna
(Müller and Henle, 1938), are described from 383 specimens (193 females
and 190 males) collected from Oct. 1995 to Sep. 1996 in waters off
northeastern Taiwan. Annuli in precaudal vertebrae form once a year and
numbered up to 21 and 17 for females and males, respectively. The von
Bertalanffy growth parameters estimates, based on age and
back-calculated length data, were as follows: asymptotic (L∞) = 288.2 cm total length (TL), growth coefficient (k) = 0.151/yr, age at 0 length (t0) = -1.988 yr for females; and L∞ = 257.4 cm TL, k = 0.203/yr, t0
= -1.709 yr for males. The growth rate for females was estimated to be
29.9 cm for the 1st year, and then decreased from 25.7 to 16.3 cm/yr
for years 2~5, from 14.0 to 7.7 cm/yr for years 6~10, and from 6.6 to
1.7 cm/yr for years 11~20. Growth rate for males was 33.4 cm/yr for the
1st year, then decreased from 27.3 to 14.8 cm/yr for years 2~5, from
12.1 to 5.4 cm/yr for years 6~10, and from 4.4 to 0.7 cm/yr for years
11~20. The mean total lengths at maturity were estimated to be 222.5
and 220.5 cm for females and males, which corresponded to 7.8 and 7.9
yr, respectively. Evidence suggested a 2 yr reproductive cycle in
females, with a gestation period of 10~12 mo. Carcharhinus brevipinna
is viviparous, with a yolk-sac placenta. The number of embryos per
litter (N) was 3~14 (mean, 8.5), and it increased with the size of the
mother (N = -45.06 + 0.198TL). TL at birth was estimated to be 65~70 cm
, and the sex ratio of embryos was 1: 1.
Key words: Age and growth, Reproduction, Spinner shark, Taiwan.
*Correspondence: Tel: 886-2-24622192 ext. 5018. Fax: 886-2-24620291. E-mail: kmliu@mail.ntou.edu.tw
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