Heterosis of Body Weights and Egg Weights of F1 Snails (Archachatina marginata var. saturalis) in Obubra, Nigeria

Abstract

A study was conducted to provide baseline information on the trends of heterosis in snail traits, so that reproductive and production performance of snails will be enhanced as is the case with other farm animal species. Three hundred (300) grower snails, one hundred and fifty each of the black-skinned (BS) and white-skinned (WS) ectotypes of Archachatina marginata snail were generated from an earlier study in the same location. The snails had weight ranging from 43.31 to 45.43 g for both ectotypes at the time of selection and were allotted into three mating groups. The mating groups are; black skinned x black skinned (BS X BS), white skinned x white skinned (WS X WS) and black skinned x white skinned (BS X WS). The mating groups were used to generate snails whose body and egg weights were compared with that of their parents. Results from the study showed that all the mating groups (BS X BS, WS X WS and BS X WS) expressed positive body weight at hatch and at the juvenile stages of growth (1 wk to 4 wk). The heterotic values for body weight were 38.89 %, 37.01 % and 53.59 % for BS X BS, WS X WS and BS X WS mating groups respectively at hatch. The heterotic value for the crossbred (BS X WS) mating group was significantly (P<0.05) different from the values of the purebred mating groups (BS X BS and WS X WS). Similarly, all the mating groups recorded positive heterotic values for egg weight at lay. The crossbred (BS X WS) mating group expressed the highest value of 60.77 % and was significantly (P<0.05) different from the values expressed by the purebred mating groups, 59.39 % for BS X BS and 54.26 % for WS X WS. The results of this study suggest that hetrosis (hybrid vigour) can be exploited to improve snails’ reproductive and growth traits if appropriate selection programme is applied. We therefore recommend the continued crossing of the black- and white- skinned snails for the production of better offspring and preservation of their genetic potentials.

Keywords: Heterosis, body, egg, weight, snail