Phenotypic Correlations and Body Weights Prediction Using Morphometric Traits of Snails in Calabar, Nigeria

Abstract

Data on hatchling body weights and morphometric traits (hatchling body shell length and hatchling body shell width) pertaining to two breeds of snails (A. marginata and A. achatina) from hatch to fourth (4th) week of age were analyzed. This was used to obtain correlation coefficient of morphometric traits and to generate prediction equations for live body weight of the animals. Strong, positive and significant correlations between hatchling body weight and body shell width (r=0.82) and between hatchling body weight and body shell length (r=0.80) for A. marginata as well as between hatchling body weight and body shell length (r=0.81) and between hatchling body weight and body shell width (r=0.86) for A. achatina were obtained. Low coefficients of determination (R²) were obtained with the range from 4.73% to 41.30% and from 2.12% to 50.20% for A. marginata and A. achatina respectively. Morphometric traits (Hatchling body shell length and body shell width) best predicted hatchling body weights of A. achatina and not of A. marginata snails. Strong, positive and significant correlations imply that selection for these morphometric traits will lead to improvement of hatchling body weights.

Keywords: Correlation, Quantitative traits, Equations, Heliculture