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Biological vulnerability of two exploited sharks of the genus Deania (Centrophoridae)

Citation

Irvine, SB and Daley, RK and Graham, KJ and Stevens, JD, Biological vulnerability of two exploited sharks of the genus Deania (Centrophoridae), Journal of Fish Biology, 80, (5) pp. 1181-1206. ISSN 0022-1112 (2012) [Refereed Article]

Copyright Statement

Copyright 2012 The Authors Journal of Fish Biology 2012 The Fisheries Society of the British Isles

DOI: doi:10.1111/j.1095-8649.2012.03262.x

Abstract

Life-history parameters of Deania calcea and Deania quadrispinosa suggested that their productivity was very low. Maturity (LT50) occurs at c. 80% of maximum observed total lengths (LT) for both species and sexes. A large proportion of mature females were neither pre-ovulatory nor pregnant, and the reproductive cycle included a distinct resting phase after pregnancy. For D. calcea, mean ovarian fecundity was 12 and maximum observed litter size was 10 (average of six); D. quadrispinosa averaged 17 pups per litter. Birth LT was 2833 cm for D. calcea and 2325 cm for D. quadrispinosa. The male and female reproductive cycles were aseasonal, and consequently, the length of the reproductive cycle could not be determined. Preliminary ageing data from dorsal-spine growth bands suggested that female D. calcea lived to 3136 years and males to 2432 years. The LT-at-age data using external bands on the spines showed maturity occurring at 155 years (males) and 215 years (females), whereas banding on the internal dentine indicated maturity at 105 and 175 years for males and females. Thus, a female lifetime of 3136 years allowed for a maximum of 7 litters if a 2 year cycle is assumed or only five litters with a 3 year cycle, resulting in a lifetime fecundity of only 42 pups (2 year cycle) or even lower (3 year cycle).

Item Details

Item Type:Refereed Article
Keywords:brier shark, deep-water dogfish, growth longsnout dogfish, reproduction, south-east Australia
Research Division:Environmental Sciences
Research Group:Environmental Science and Management
Research Field:Environmental Management
Objective Division:Environment
Objective Group:Environmental and Natural Resource Evaluation
Objective Field:Environmental Lifecycle Assessment
Author:Daley, RK (Mr Ross Daley)
ID Code:117024
Year Published:2012
Web of Science® Times Cited:11
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2017-05-29
Last Modified:2017-10-20
Downloads:0

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