Etude quantitative des nématodes libres des secteurs nord et est de la lagune de Bizerte (Tunisie)

Abstract

The study done in the northern sector of Bizerta lagoon shew that densities and biomasses of free-living nematodes are strictly dependent on physico-chemical, sedimentological and geochemical parameters. Indeed, superficial sediments of this sector has shown a very fine facies enriched with organic matter, rejected by domestic and industrial areas of the neighbouring cities. This situation favors the formation of organo-minerals complex between mineral particles, in particular smectite and organic compounds. Marine free-living nematodes react to these unfavorable superficial conditions through migration to the deepest horizons, but the deposit feeders species are more resistant toward the excess of superficial organic matter.