Tekou Guegang, Judith Georgette Makombu, Claudine Tekounegning Tiogue, Alexia Kevine Noubissi Chiassa, Pamela Cynthia Mepa Tchiegang, Boddis Tsigua Zebaze, Augustave Kenfack,
Volume 2, Issue 4 (12-2020)
In order to evaluate wild clams for possible domestication with a view to aquaculture, the present study focused on the phenotypic characteristics of wild clams of the genus Egeria Roissy, 1805 in the Lower Sanaga River of Cameroon, with the main objective of contributing to a better understanding of their biology. A total of 2340 clams of different sizes were collected between March 2018 to March 2019 at three sites in the lower part of the Sanaga River, namely Bolounga-Moulongo, Mpombo-Boloy and Maldjedou-Bonapembe. Phenotypic characteristics (including internal and exterior coloration of the shell, type and number of shell stripes, color of the mantle, shape of the pallial sinus, and indices of elongation, compactness and convexity) were collected on each individual and evaluated according to the site and the season. The results showed four predominant colors on the exterior face of the shell (66.0% yellow, 29.1% brown, 4.7% dark and 0.2% pink), three colors on the internal face of the shell (89.4% white, 10.5% white-purple and 0.1% white-pink), three types and number of shell stripes (57.8% visible stripes, 23.4% barely visible stripes and 18.8% absent stripes), two colors of the mantle (17.5% white and 82.5% orange), two types of the pallial sinus (60.5% dorsally angular, and 39.5% regularly rounded), 99.8% oval shapes (elongation index), 99.7% convex shapes (convexity index) and 52.7% compact shapes (compactness index). The results for clam characteristics were not influenced by the site nor the season, apart from the compactness index which varied according to the site. Phenotypically, the clams of the Lower Sanaga River showed several similarities with the species Egeria radiata and the specimens that showed a pink color of the shell similar to the species Egeria rubicunda. Molecular characterization is therefore necessary to explain the origin of the diversity of phenotypic characteristics in the clam’s species population in this area.
|