Vol. 2, Issue 6 (2017)
Diversity of phytoplankton for nutritional selectivity by Galatea paradoxa (born 1780) of lower sanaga delta, Cameroon
Author(s): Adolphe Dikoume, Gordon Ajonina, Minette Tomedi
Abstract: Background: In Cameroon, Galatea paradoxa clams are present in the delta of the low Sanaga in Mouanko. There are data gaps concerning clams associated to the present food potential in the low Sanaga. Strategy to domesticate this resource requires the knowledge of its bio-ecology. This study aimed to evaluate diversity of phytoplankton for nutritional selectivity by Manila clams within the lower Sanaga delta. Each point has been done a qualitative and quantitative sampling. Some liters of water were filtered with the net to plankton, content has been poured in a bottle in glass labeled and analyse to laboratory. Results: A rich taxonomic diversity of phytoplankton (117 species, 75genera and 7 classes, all left in 5 phyla) was observed with an important specific richness of the Cyanophyceae classes (the richest 41 species; 35.0%) follows by the Diatomophyceae classes (35 species; 29.9%). Rhodophyta’s phylum was absent. The most abundant classes were those of Diatomophyceaes (114; 33.3%) and Cyanophyceaes (111; 32.5%). Some likeness have been observed between sampling stations and index of Shannon (H’) has been raised (H'>0: H'1=3.59; H'2=3.73; H'3 = 3.88); Equitability index (E) was close to 1 (E≈1: E1 = E2 = E3=0.96) and Dominance (d) was weak (d→0: d1=0.41; d2=d3 = 0.36). An important fraction of exploitable of clams bound both to the favorable conditions of environment and to absence of a minimal size of exploitation. Thus, diversity of phytoplankton and likeness observed between the stations could be due to the exchanges with the vicinity (contributions of continental waters and opening to the Atlantic Ocean) and to proximity between the stations. Conclusions: Mouanko, a zone of mouth, could justify the favorable conditions of growth of clams. Site is a rich environment with nourishing matters necessary to support production of phytoplankton useful to clams, and could constitute favorable conditions to domesticate bivalves.