THE SYSTEMATICS AND TRANSMISSION OF NEW AND PREVIOUSLY DESCRIBED METASTRONGYLES (NEMATODA : METASTRONGYLIDAE) FROM MUSTELA VISON

Abstract

Crenosoma hermani n. sp., Aelurostrongylus pridhami n. sp., and Filaroides martis from mink are described. A. pridhami developed in the terrestrial gastropods Zonitoides arboreus, Discus cronkhitei, Deroceras gracile, Succinea ovalis, and Anguispira alternata and the aquatic snails Physa integra, Gyraulus deflexus, Armiger crista, and Ampullaria cuprina. F. martis developed in P. integra and G. deflexus as well as in the foregoing terrestrial gastropods. Larvae of A. pridhami and F. martis infected gastropods by penetrating the foot but those ingested penetrated the gut wall and developed successfully. Besides the foot, larvae developed on, or within, the body wall, in the mantle, on the gut, on the surface of the liver, in the buccal mass, salivary gland, and rarely in the albumen gland of molluscs. At 22–23 °C the first molt occurred on the 5th to 6th day, the second on the 13th; the three larval stages are described. The prepatent period of A. pridhami was 21–28 days, F. martis 41–53 days. Mink invariably vomited when fed infective larvae of A. pridhami but not when fed F. martis. Infective larvae of A. pridhami became encapsulated in the liver of mice, small birds, and frogs but on the intestines and mesenteries of goldfish. F. martis larvae became encapsulated in the liver of mice. There is a sigmoidal relationship between temperature and activity of first-stage larvae of A. pridhami. Young D. gracile fed and became infected with A. pridhami and F. martis at temperatures as low as 5 °C. Desiccation killed larvae in a few minutes and they survived freezing temperatures for only 4 to 5 days.