Scale stocking checks to differentiate between hatchery-reared and wild mulloway Argyrosomus japonicus |
| |
| Authors: | M D TAYLOR & R F PIOLA |
| |
| Institution: | Ecology and Evolution Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia |
| |
| 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. |
| |
| Keywords: | mulloway re-stocking scale increment stock enhancement stocking checks |
|
|
