Geographical variability in life-history traits of a midslope dogfish: the brier shark
Published online on 01. September 2015
Geographical variability in life-history traits of a midslope dogfish:
the brier shark Deania calcea
B. E. A. Rochowski, T. I. Walker, R. W. Day
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.
Journal of Fish Biology, Volume 87, Issue 3, pages 728–747. doi: 10.1111/jfb.12756