Microsatellite Parentage Analysis of Cultured Juvenile Florida Largemouth Bass Micropterus Floridanus Displaying Variable Traits of Growth and Aggression

This study investigates the heritability of physiological and behavioral characteristics in juvenile Florida largemouth bass Micropterus floridanus. Microsatellite parentage analysis was used to reconstruct familial relationships of cultured Florida bass displaying variable traits of growth and aggression. Age-0 juveniles were segregated into two groups according to size and randomly sampled; baseline growth and aggression group (BGA;N=250) and high growth and aggression group (HGA; N=250). Ten microsatellite loci were used for assignment of offspring to 119 potential wild-type brooders (males N=47, females N=72). Offspring of the BGA group represented significantly more parents (44 unique parents; 31 pairings) than offspring of the HGA group (25 unique parents; 14 pairings). There was a significant difference in contribution of the top three parent-pairs between groups (BGA=48%; HGA=90%). This was due to a majority of the HGA group (83%) being represented by one pair (P22/P25). The pair showed a significantly reduced contribution to the BGA group (7%). A difference was observed in the display of aggressive individuals between the two groups (BGA N=1; HGA N=29). A majority of aggressive fish resulted from the P22/P25 pairing (N=21). Results show that the potential for trait heritability should be taken into consideration when managing for trophy fisheries.