Family-tank interactions on early growth performance of yellow perch reared in single-family tanks versus mixed-family tanks as inferred using microsatellite pedigrees

From 17 families, 400 fingerlings were evenly stocked into four replicates of each of five groups: single family from an Ohio strain, single family from a North Carolina strain, three families from the cross of five strains, 12 families from the cross of five strains and a combination of all 17 families. After rearing for 27 weeks, the progeny from the 17 families could be confidently assigned to their family of origin at the rate of 97.9%. The cross-bred multi-families (12-family and 3-family groups) from different strains gained significantly more weight than both single-family groups in separate tanks throughout most of the experiment (P<0.05), but no significant differences were detected in body weight among the four groups in the all-family communal tanks (P>0.05). Both single families grew significantly faster in the all-family communal tanks than in single-family tanks by the end of the experiment (P<0.05). In addition, no correlation was detected between family mean weight obtained from the multi-family tanks (12-family and 3-family groups) and the family mean weight in the all-family tanks. These results indicated that there were strong effects of genotype by environment interactions on early growth performance of yellow perch.