
TY  - JOUR
A1  - Willett, DJ 
T1  - Use of scale patterns to evaluate stocking success of silver perch, <I>Bidyanus bidyanus</I> (Mitchell), released at two different sizes
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 1996
VL  - 47
IS  - 5
SP  - 757
EP  - 761
KW  - 
UR  - https://doi.org/10.1071/MF9960757 
N2  - A study was conducted to determine relative success of stocking silver perch (Bidyanus bidyanus) at two different sizes: 35 mm and 50 mm total length. By purposeful manipulation of growth rates of pre-stocked fish it was possible to induce unique markers in scale circulus patterns, thus differentially marking the two size-groups. The scale circulus data were acquired with automated video-digitizing equipment. Both size-classes were stocked into two south-eastern Queensland impoundments. Relative stocking success after two years was quantified by sampling surviving silver perch and using discriminant function analysis to assign individuals to their respective size-at-release groups. Relative survival of fish stocked at 35 mm and at 50 mm was not significantly different in either impoundment. Post-stocking growth rates of 35 mm fish were not compromised due to their smaller size at release. From a management perspective, this suggests that 35 mm is a more cost-effective release size of silver perch than 50 mm. This trial demonstrates the feasibility of using scale circulus patterns to differentially mark multiple groups of fingerlings for such controlled experiments. 
ER  -

