Heritability estimation for growth-related traits in juvenile wild common carp (Cyprinus carpio L.) in the south of Caspian Sea

Abstract

Wild common carp of the Caspian Sea is one of the important fish in the north of Iran, which has been introduced to inland aquaculture. Its genetic characteristics are investigated to set up for breeding programs that are still unknown. Using wild common carp in aquaculture is limited for uncontrolled variation in performance of fish derived from undomesticated breeders. A 7×7 factorial mating design was employed to examine genetic effects of dam and sire on growth and heritability of growth-related traits based on dam half-sib and sire half-sib families. Breeders were obtained originally from the Caspian Sea. A total of 1470 offspring were raised in 49 separate fiberglass tanks with common conditions. Body weight and length were recorded at three different ages of rearing. Estimation of heritability of weights ranged from 0.23±0.05 to 0.30±0.07 for dams and ranged from 0.15±0.03 to 0.26±0.04 for sire. Similar results were obtained with length but with less variation (0.24±0.02 to 0.26±0.01 for dams and 0.20±0.02 to 0.22±0.03 for sire). The broad-sense of weight and length are 0.23±0.04 and 0.23±0.01 respectively. The dam and sire effect on growth were significant, indicating the presence of variations among the native fish of the Caspian Sea. Therefore, it is suggested to use a length for selection that is more reliable and less affected by environment than weight at any time of growth and in respect of high phenotypic correlation (0.87-0.95) observed between weight and length. In the present study we even used wild common carp and the heritability was not higher than the domesticated common carp. It means the genetic variation for quantitative traits, for common carp of the Caspian Sea are low or it may be under pressure of inbreeding which should be studied further.