FRESHWATER CRAYFISH | 2006| vol. 15| Research Article
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Full Citation: LAWRENCE, C. S., MORRISSY, N. M., VERCOE, P.E. & WILLIAMS, I. H. (2006). Cherax of south-eastern and central Australia. Part 3: Differences in growth rate, size at sexual maturity and sex ratio. Freshwater Crayfish 15: 24-35.
Populations of yabbies in Australia have evolved in geographical isolation since the Tertiary period. We tested the hypothesis that yabbies belonging to the Cherax spp. complex distributed throughout south eastern and central Australia would have different growth rates, sex ratios, and size at sexual maturity, as this has been reported for allopatric populations of other freshwater crayfish species. To test this hypothesis, yabbies were collected from fourteen allopatric populations across Australia and transported to a laboratorywhere they bred and the performance of their progeny in aquaria recorded. Growth rates of these progeny varied among parental populations (P < 0.001). Cherax rotundus from Karuah, New South Wales and C. destructor from Algebuckina, South Australia had the highest growth rates (47 - 56 mg/day), which were 8 - 9 times higher than the population with the lowest growth rate, C. dispar from Brisbane, Queensland (6 mg/day). The sex ratio of yabbies within each of the populations was not significantly different from 1 female: 1 male and all populations were capable of reproducing at less than 12 months of age. The minimum size of berried females also varied among populations. The smallest recorded was 3 g for C. dispar from Brisbane while C. albidus from Nurrabiel had the largest minimum size at sexual maturity (20 g). The variation in growth and size at sexual maturity in the populations of yabbies used in this experiment could be useful for improving the productivity of yabbies in aquaculture.
Keywords: yabbies; Cherax; growth; sexual maturity; sex ratio
Article Language: English
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