Changes in Biochemical Composition of the Gonads of Donax trunculus L. (Mollusca, Bivalvia) from the Gulf of Annaba (Algeria) in Relation to Reproductive Events and Pollution

Seasonal changes in biochemical composition of the bivalve Donax trunculus L. (Mollusca, Bivalvia) were studied during eight months from January to August 2009 in the gulf of Annaba. The samples were collected monthly at two sites: El Battah, a site far from any source of pollution, and Sidi Salem, a site located near human and industrial wastes. The amounts of carbohydrate, lipid, and protein were determined in gonad-visceral mass. The monthly amounts of the different components in gonads varied from 33.68 to 118.09 for carbohydrates, 6.68 to 44.45 for lipids and 3.56 to 36.72 μg/mg of wet tissue for proteins, respectively. A three-way ANOVA indicated significant effects of time, sex, and treatment. Lowest values of components were observed during the spawning phase. There was a significant difference in amounts of these gonad components between the two sites. Globally, the lowest values of carbohydrate and proteins, and the highest values of lipids were recorded in individuals sampled at Sidi Salem.