Over the period of a year, the Nematodes from a stretch of stagnant water of the Po associated with Spirogyra were studied. Of the 12 species found the following are to be considered as «Leitformen»: Tobrilus consimilis, T. longus, Diplogaster rivalis, Plectus cirraius and Monhysfera spp. Measures were taken of examples of the Tobrilus genus supplied with vulva and, respectively, of spicules which pointed out the allometry in the final stage of growth (fig. 1). For the four dominating genera seasonal variations were also observed concerning their number and biomass (figs. 2 and 3) and ecological considerations were made.
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Con il contributo del Ministero per i Beni e le Attività Culturali