Evaluation of Growth and Correlations Between Body Weight and Shell Measurements of the Juveniles of Two Ectotypes of Archachatina Margi nata var. S aturalis (P) Snail

Abstract

This study provides information on the growth and correlations between body traits of juveniles of two ecto- types of snail(Archachatina marginata var. saturalis (P)). Three hundred juveniles, one hundred and fifty each of the black-skinned (BS) and white-skinned (WS) ectotypes selected from a pool on the basis of active appearance and absence of injury, blister or lesion on the foot and/or shell were used for the study. The selected juveniles were grouped into two on the basis of skin (foot) colour. Each group was replicated five times with ten juveniles per group in a completely randomized design. The results of this study showed that during the juvenile phase of growth, there was progressive weight increment with significant differences (P 0.05) after week two could mean that irrespective of their pigmentation and weight at hatch, juveniles of a particular breed always grow to catch up with others within the same environment. The results also showed that growth in terms of weight gain was generally low/slow during the first few weeks of life after hatch. The reason for this could be that the juveniles eat little or no feed (concentrate and/or forage) during this stage of life. The results of estimates of association between traits showed that all evaluated traits had strong positive correlations in the two snail ec- totypes studied. The correlations between these traits were highly significant (P<0.001). The positive correlation values recorded among these traits could mean that the traits are influenced by the same genes in the same direction, and that there are direct relationships between the traits. Besides, it could be that weight increment in snails is as a result of increase in the size of corresponding traits. The high degree of correlation among traits indicates that selection for one trait will lead to improvement in the other trait. The results of this study could guide breeders in the development of stocks, and thus increase the availability of animal protein for the teeming Nigerian populace.