Résumé:
Our study focused on the biometric analysis of cortical development as well as the total weight of the selected biomarker species "Siphonaria pectinata", in two different sites. The first being that of Stidia (STD), a site far from human settlements characterized by remarkable cleanliness and the Salamandre Harbor (SH) (polluted site). The work consisted of a three-month measurement follow-up (February, March and April) of 360 individuals of these gastropod molluscs, namely: shell height (H), length (L), width (La) and the anterior Summit (Sa), posterior vertex (Sp) as well as the total weight (Pt) of all the S. pectinata collected. The correlation was made between the different measurements (Length - Width. Height - Length, Width. Total weight - Length, Width, Height and the anterior vertex - posterior vertex) The results were processed and analyzed by following the power (y = axb) and linear (y = ax + b) curves as well as the Student's t test. Through the results obtained, which reveal the lower and upper differential relationships between different biological variables, we were able to notice that the development of the shell of the false limpet begins with the height first, followed by the length second, passing through the width, and finally, the total weight takes the last place, since it registers the slowest growth rate in relation to the three previously mentioned parameters. The posterior vertex grows more slowly than the anterior vertex. These results were observed for the two size classes studied. These results confirm that the growth of this Mollusc varies and depends on several biotic and abiotic factors which also condition the development of the shell and the growth of the weight of Siphonaria pectinata. This approach represents a good means of environmental assessment.
