Technical Notes: Evaluation of an Electronic Fry Counter with Striped Bass Embryos and Larvae

Abstract

Abstract We evaluated an electronic fry counter (Jensorter, Inc., model FC-2) for accuracy, precision, and effects on embryo hatchability and larval survival of striped bass Morone saxatilis. Hatching success of embryos and 96-h survival of 5-d larvae passed through the counter did not differ significantly (P > 0.05) from controls. Mean electronic counts of embryos and larvae differed from hand counts by –5.2% and –9.7%, respectively. Precision was estimated by the coefficient of variation of repeated counts and ranged as high as 4.43% for embryos and 8,62% for larvae. Site- and species-specific factors may have increased variability that resulted in the reduced levels of accuracy and precision. The advantages of greatly increased speed of counting and ease of use, as well as potentially better performance under other conditions, warrant further evaluation of this counter with other species and water supplies.