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Fecundity and its variability in orange roughy: effects of population density, condition, egg size, and senescence

Citation

Koslow, J and Bell, J and Virtue, P and Smith, D, Fecundity and its variability in orange roughy: effects of population density, condition, egg size, and senescence, Journal of Fish Biology, 47 pp. 1063-1080. ISSN 0022-1112 (1995) [Refereed Article]

Copyright Statement

Copyright 1995 The Fisheries Society of the British Isles

DOI: doi:10.1111/j.1095-8649.1995.tb06030.x

Abstract

Fecundity of orange roughy in 1987-1989 adjusted for standard length (s.L.) varied significantly between New South Wales (42 787 eggs female- ') South Australia (35 339 eggs female ~ I ) and east Tasmania (31 085 eggs female-'). Only 1&17% of the variability in fecundity of eastern Tasmania orange roughy was explained by S.L. in any year from 1987-1992. However, liver condition and age of the fish, in combination with s.L., explained 27% of the variation in fecundity. Fecundity declined in fish over 60 years old. It was also significantly correlated with lipid levels in the ovary, in particular, with triacylglycerol as a proportion of the total lipid fraction. Significant interannual changes in fecundity appeared to be related to the impact of fishing. From 1987-1992, the orange roughy stock off east Tasmania was reduced by 50% by the fishery, and mean fecundity increased 20% over that period. This compensatory increase in individual fecundity, combined with an apparent increase in the proportion of females spawning annually from 54 to 71%, limited the decline in the population's egg production over this period to approximately 15%.

Item Details

Item Type:Refereed Article
Keywords:fecundity; density-dependence; condition factor; senescence; orange roughy.
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and Estuarine Ecology (incl. Marine Ichthyology)
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Antarctic and Sub-Antarctic Flora, Fauna and Biodiversity
Author:Virtue, P (Associate Professor Patti Virtue)
ID Code:90441
Year Published:1995
Web of Science® Times Cited:58
Deposited By:IMAS Research and Education Centre
Deposited On:2014-04-03
Last Modified:2014-06-10
Downloads:0

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