Geographical variability in life-history traits of a midslope dogfish: the brier shark Deania calcea.
Deania calcea (n = 420) were collected from the catch of deep-water trawlers in the southern and eastern scalefish and shark fishery in southern Australia during the years 2008-2011. The total length (LT ) range varied between sexes, females being larger (n = 264; 280-1530 mm) than males (n = 156; 310-921 mm). The reproductive cycle in this population is non-continuous and asynchronous. The estimated LT at which 50% of males are mature is 807 mm and is 914 mm for females. Populations of D. calcea in higher latitudes appear to mature at a larger size than conspecifics in lower latitudes, in both the northern and southern hemispheres. Litters ranged from three to 10 embryos with a 1:1 sex ratio, but litter size does not increase with maternal LT . Deania calcea shows geographical variability in its biological parameters and gathering information on life-history traits of populations is vital to understand the trade-offs made by this species in response to environmental conditions and to predict intraspecific spatial differences. Such information is a basis for specific spatial management to protect populations from excessive fishing.
School of Biosciences, The University of Melbourne, Grattan St, Parkville, Vic 3010, Australia.
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Rochowski
School of Biosciences, The University of Melbourne, Grattan St, Parkville, Vic 3010, Australia.
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Walker
School of Biosciences, The University of Melbourne, Grattan St, Parkville, Vic 3010, Australia.
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RW
Day
D000818:Animals; D001315:Australia; D049628:Body Size; D052284:Clutch Size; D004284:Dogfish / Q000502:physiology*; D004777:Environment; D005260:Female; D005398:Fisheries; D005843:Geography; D008297:Male; D012098:Reproduction / Q000502:physiology*; D012744:Sex Ratio; D012741:Sexual Maturation
deep-water chondrichthyan; elasmobranch biological parameters; litter size; maturity