AQUATIC NEMATODES FROM ETHIOPIA .2. THE GENUS MONHYSTRELLA COBB, 1918(MONHYSTERIDAE, NEMATODA) WITH THE DESCRIPTION OF 6 NEW SPECIES

Eight species of the genus Monhystrella, six of which are new to scien ce, are described from bottom samples collected from three lakes, two rivers and a hot spring in Ethiopia. Monhystrella hoogewijsi n. sp, is identified by a distinctive bulge on the lip region, position of the amphids, offset and well developed single pharyngeal terminal bulb, ta il shorter than vulva-anus distance, tail elongate-conoid for two-thir ds of its length, and by the shape and size of the spinneret outlet; M . jacobsi n. sp. by its slender body, distinctively offset and distend ed lip region, indistinct and weakly expanding single terminal pharyng eal bulb, and shape and size of the tail and spinneret outlet; M. arsi ensis n. sp. by its single terminal pharyngeal bulb, position of amphi ds, shape and length of tail and spinneret outlet; M. woitorum n. sp. by its hemispherical lip region, double terminal pharyngeal bulb, shap e and length of the spinneret outlet, and shape and length of tail; M. ethiopica n. sp. by its bipartite stoma, size of amphid in relation t o corresponding body width, filiform tail and shape and length of spin neret outlet. M. atteae n. sp. differs from all known Monhystrella spe cies in having an inflated cap-like lip region and fine crystalloid bo dies. M. macrura (de Man, 1880) Andrassy, 1981 and M. lepidura altherr i (Juget, 1969) Jacobs, 1987 are reported from Ethiopia for the first time. Crystalloid bodies in the genus Monhystrella is reported here fo r the first time. Also the presence of a hyaline coelomocyte next to t he germinal zone of the reproductive system is reported for the first time in the genus here in all eight species. The structures used in th e taxonomy of the genus are reviewed.