Abstract
An experiment was conducted to make out if an antimitotic agent, the Colchicine, may have negative effects on a nematode community from the "Rimel" beach (Bizerte bay, NE Tunisia). Three sedimentary doses of Colchicine (in Dry Weight) (1.5428 ppm, 15.428 ppm and 154.28 ppm) were tested during 30 days of exposure. Univariate analyses showed a clear decrease in terms of quantity and quality of nematodes present in Colchicine treatments compared to the control. Multivariate analyses revealed a discernible reorganization of the community evidently due to the different species sensitivities against Colchicine. The nematode species Ptycholaimellus ponticus, Theristus modicus and Kraspedonema reflectans were identified as Colchicine-sensitive, due to population reduction after treatment. The Colchicine seems acting on these species by direct epidermic contact, by internalization through cuticular pores or by ingestion of contaminated sediment particles. Our results appeared rejecting the eutely for cells of the cuticular epidermis and those of the digestive tube of Ptycholaimellus ponticus, Theristus modicus and Kraspedonema reflectans