|
|||||
|
|
Genetic and environmental variability of adult size in some stocks of the edible snail, Helix aspersa |
|
| Authors: | Mathilde Dupont-Nivet Annie Guiller and Jean-Claude Bonnet |
| Institution: | Institut National de la Recherche Agronomique, Domaine du Magneraud, Heliciculture, BP 52, 17700 Surgères, France;Laboratoire de Zoologie et d'Ecophysiologie (L.A. INRA), Universitéde Rennes I, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes Cedex, France |
| Abstract: | This paper aims at providing a better knowledge of factors determining body size (especially the importance of heredity) in Helix aspersa Müller. A preliminary investigation of snails from Maghreb allowed us to show the importance of heredity in the variability of body size and to produce an efficient design for a subsequent reliable estimation of heritabilities. All traits measured (diameter, height and weight) were highly correlated and weight appeared to be the most convenient measure of size. The second experiment provided 4150 snails born from known individuals among 500 wild snails. Pedigrees were recorded. Weight and diameter revealed high heritabilities (>0.4), which is relevant for commercial selection since variability of both traits was important. The design also revealed a significant non-genetic maternal effect and also that offspring from pairs where only one animal laid were bigger than offspring from pairs where both animals laid. This surprising observation has to be confirmed and its mechanisms studied. |
| Keywords: | |