Evaluation biométrique de la fausse patelle (Siphonaria pectinata) issue de deux sites contrastés de la côte Mostaganemoise.

Abstract

The interest in the false limpet Siphonaria pectinata (Linné, 1758) is linked to the importance of these relationships with the marine phytobenthos being a gastropod mollusk very frequent on all the rocky coasts of western Algeria thus exposing complex ecological and behaviors that vary from one environment to another depending on the degree of pollution.Our study includes a part which concerns the analysis of the biometric diversity of S. pectinata populating two rocky sites namely Stidia (STD) and the Mostaganem harbor (PM). The main objective of this study is the evaluation of the resistance of the latter, also to rule on its profile, it remains so far poorly known because apart from the similar study the previous year(2019), no study has been consecrated. The work consists of a series of measurements carried out on a one-month sampling of the biometric indices of 120 individuals of this Mollusc Gastropod, namely: the height of the shell (H), the length (L) the width (La), apex anterior (Sa), posterior apex (Sp) and the total fresh weight (Pt) are performed for all populations of S. spectinata. The correlation of the different measurements (length-height, length-width, length-total weight, height-total weight, width-total weight, posterior apexanterior apex) was treated and analyzed following the power curves of the form y = axb and following the STUDENT "t" test. The results obtained concerning biometrics reveal major allometric and isometric relationships but the dominance goes to the minor allometry between the different biological parameters. It has been observed that the false limp promotes the development of its shell in height followed by the width and the length and finally the increase in the total fresh weight. The anterior apex when it grows more slowly than the posterior apex. It is indeed an adaptive response to the physical and ecological conditions of the environment. This study showed that there is no significant difference (p <0.05) between the morphometric characteristics of the two populations studied. This approach represents a good means of environmental assessment that could be used in biomonitoring programs..