Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 31. (Budapest, 1998)

Description of Chiostkhorchis lobatotestis sp. n. (Trematoda, Amphistomida) from the spiny rat Mesomys sp. from Brazil Otto SEY

1 and Vernon E. THATCHER

2 Department of Biological Sciences, University of Kuwait, P.O.Box 5969, Safat 13060, Kuwait 2 Instituto National de Pesquisas da Amazonia, Caixa postal 478, 69011-970, Manaus/AM, Brazil (Received 15 November, 1997) Abstract: Chiostichorchis lobatotestis sp. n. is described from the caecum of the spiny ra.tMesom.ys sp. (Rodentia, Echimyidae) from Brazil. The newly described species differs from the only other species of the genus by having deeply lobed testes, smaller and slightly modified terminal genitalium, position of genital organs and different host. Key words: Amphistomida, Chiostichorchis lobatotestis sp. n., Mesomys sp., Brazil INTRODUCTION Helminth parasites, and especially the amphistomes of Brazilian rodents have scantly been studied. Taxorchis schistocotyle (Fischoeder, 1901), Chiostichorchis myopotami (Sprehn, 1932), Taxorchis rinqueleti Sutton, 1975 and recently Paraibatrema inesperatum Ueta, Deberaldini, Cordeiro et Artigas, 1981 have been reported from different groups of rodents. The present paper is a description of a new amphistome from an additional group of rodents. MATERIALS AND METHODS One of the three specimens of Mesomys sp. obtained from the Jurua river, Acre State, Brazil on 9 June 1992 was infected with seven specimens of this trematode. Worms were washed in saline, fixed in AFA under slight coverglass pressure, and stored in 70% ethanol. Whole mounts as well as median sagittal sections were prepared as described elsewhere (Sey 1991). All measurements are in micrometer unless otherwise stated. Drawing was prepared by microprojection and details filled in through microscopic observations.