ESTUDIO SISTEMATICO DE LOS TREMATODOS PARASITOS DE LOS "AJOLOTES" DE MEXICO

Resumen

This paper is another contribution of a series studying the parasites of the "Ajolotes" Ambystoma tigrinum of Mexico from the lake of Xochimilco, D. F., and the marshes of Lerma, State of Mexico; and Rhyacosiredon altamirani in Contreras. D. F.
In the ajolotes from Xochimilco we found two Trematoda already known: Megalodiscus temperatus (Stafford, 1905) Harwood 1932 living in the cloaca, and Gorgoderina attenuata Stafford, 1902 from the urinary bladder.
Two new species of Trematoda were found:
Phyllodistomum rhyacosiredonis n. sp. which in general aspect resembles somewhat P. americanum Osborn, 1903, P. parasiluri Yamaguti, 1934 and P. nocomis Fischthal 1942, differing from them by the following characters: it is larger; the oral sucker is small in relation to the acetabulum; the convolutions of the intestine very abundant, reaching the acetabulum; the eggs smaller than in other large species. (The measurements
of the four species are compared in a chart).
Haematoloechus pulcher n . sp. from the lungs of Ambystoma tigrinum from the marshes of Lerma, which, when compared with other species of the genus showed only a small resemblance to H. tumidus Ingles, 1932, in the presence of cuticular spines in the pre-acetabular region and the distribution of the sexual organs. lt differs from this species in size, H. pulcher being much larger; the relation in size between the two suckers, varies; also the distribution of the pre-acetabular vitellaria. The existence of large glandular masses on both sides of the pharynx is distinctive of H. pulcher n. sp.