Scale stocking checks to differentiate between hatchery-reared and wild mulloway Argyrosomus japonicus |
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Authors: | M. D. TAYLOR,& R. F. PIOLA |
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Affiliation: | Ecology and Evolution Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia |
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Abstract: | Abstract Scales from hatchery-reared, stocked and wild mulloway Argyrosomus japonicus (Temminck and Schlegel) captured in the Georges River, and a library of mulloway scales from coastal New South Wales, were examined for the presence of scale checks. Checks specific for hatchery-reared fish were present in 100% of recaptured hatchery-reared mulloway; the origin of which was confirmed by the presence of a chemical mark in the otolith or fin spine. Up to 7% of wild mulloway were incorrectly classified as hatchery-reared on the basis of these checks. An abrupt reduction in salinity from 35 to 5 and 6 days starvation successfully induced checks in the scales of hatchery-reared mulloway. The marking efficiency for stocking checks was comparable to that obtained using oxytetracycline hydrochloride, and supports the short-term use of scale stocking checks to evaluate mulloway stock enhancement programmes in Australia. |
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Keywords: | mulloway re-stocking scale increment stock enhancement stocking checks |
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