Quantitative genetics of growth traits in the edible snail, Helix aspersa Muller

Abstract

Genetic parameters of adult weight, age at maturity (adult age), weight after hibernation and relative loss of weight during hibernation were estimated in a population of edible snails (Helix aspersa Muller). Eight thousand four hundred and eighthy three animals were sampled from 143 pairs for adult weight, 4 333 from 87 pairs for adult age and 2 256 from 123 pairs for traits after hibernation. An animal model taking into account all the relationships was used to estimate genetic parameters. Estimates were also computed from the covariances between full-sibs and parent offspring regressions to assess possible non-additive genetic effects. Heritabilities were high except for relative loss of weight during hibernation. Estimates from the animal model were 0.48 ± 0.04 for adult weight, 0.40 ± 0.05 for adult age, 0.40 ± 0.05 for weight after hibernation and 0.12 ± 0.03 for relative loss of weight during hibernation. Adult weight and adult age were neither phenotypically nor genetically correlated (0.05 and 0.003 ± 0.07, respectively). A substantial maternal effect, especially on adult weight was found.