A new genus and species of Macroderoididae, and other digeneans from fishes of Lake Malawi, Africa.

Malawitrema staufferi n. gen., n. sp., an unusual digenean, is described from Clarias mossambicus (type host) and Bagrus meridionalis from Lake Malawi. It has a small, pyriform body, with a spinous tegument. The ceca are relative short, not reaching to the testes. The 2 testes are symmetrical in the middle hind body. The cirrus sac is long and narrow, reaching into hind body. The genital pore is median, immediately anterior to the ventral sucker. The ovary is pretesticular, and a canalicular seminal vesicle and Laurer's canal are present. The uterus usually reaches distinctly posteriorly to testes. The eggs are small. The follicular vitellarium is in 2 small fields just anterior to testes. The ventrally subterminal excretory pore leads to a claviform vesicle. This species does not fit clearly into any known family of digeneans and is placed in the Macroderoididae as a temporary measure. Other digeneans reported from Lake Malawi include Haplorchoides cahirinus (Looss, 1896) in C. mossambicus and B. meridionalis; Astiotrema turneri Bray, van Oosterhout, Blais & Cable, 2006 in Protomelas annectens, P. cf. taeniolatus, Labeotropheus fuelleborni, Ctenopharynx (Otopharynx) pictus, and Pseudotropheus zebra; Glossidium pedatum Looss, 1899 in C. mossambicus and B. meridionalis; and an unidentifiable sanguinicolid from Bathyclarias nyasensis.