DURIKAINEMA PHASCOLARCTI N. SP. (NEMATODA, MUSPICEOIDEA, ROBERTDOLLFUSIDAE) FROM THE PULMONARY-ARTERIES OF THE KOALA PHASCOLARCTOS-CINEREUSWITH ASSOCIATED PATHOLOGICAL-CHANGES

Durikainema phascolarcti n. sp. (Nematoda: Muspiceoidea) is described from koalas Phascolarctos cinereus in coastal New South Wales, Austral ia. Adults were recovered from pulmonary arteries and arterioles, and larvae were observed in blood vessels and free in tissues of lung, cer ebellum, medulla oblongata, liver, kidney, uterus, cervix and bladder. D. phascolarcti is distinguished from D. macropi; the only other memb er of the genus, by the minute size of the male (easily mistaken for a larva), the small size and simple shape of the spicule, the reduced n umber and exclusively post-anal position of the caudal papillae in the male, the shorter length of the larva and the presence of a large cut icular cephalic inflation in the larva, as occurs in adults. No reacti ons were observed in pulmonary arteries and medium-sized vessels conta ining adult D, phascolarcti. Nevertheless, some individual transverse sections of these pulmonary vessels contained as many as 135 sections of nematode occupying >95% of the diameter of the vessel. Such levels of infection in these important vessels probably compromise respiratio n and circulation, and affect the health of the animal.