Morphological and molecular identification of amphistomes of wild ruminants from selected conservancies of Matebeleland region of Zimbabwe

Amphistomosis is a poorly understood trematode disease of domestic and wild ruminants whose effect has been underestimated. To date, there is limited information on the taxonomic status of amphistome species, particularly in sub-Saharan Africa which is home to diverse species infecting domestic and wild ruminants. In view of this, a survey was conducted in wildlife conservancies and national parks located in Beitbridge, Nyamandlovu, and Hwange in the Matebeleland region of Zimbabwe during the 2019-2021 game hunting seasons. Gastrointestinal tract of 329 carcasses of wild ruminants were examined for amphistome infections and 33/329 (10 %) of the animals were infected and the highest prevalence per locality was in Hwange (35 %; 7/20). A high prevalence of 63 % was recorded in <i>Kobus ellipsiprymnus</i> (waterbuck) from Beitbridge, accompanied with a high parasitic burden of more than 10 000 parasites per animal. The lowest parasitic burden was observed in <i>Connochaetes taurinus taurinus</i> (blue wildebeest) and <i>Hippotragus niger</i> (sable), each with less than 10 amphistomes. A total of 86 amphistome specimens from <i>Syncerus caffer</i> (African buffalo) (n = 27), <i>Aepyceros melampus</i> (impala) (n = 17), <i>Tragelaphus strepsiceros</i> (kudu) (n = 16), waterbuck (n = 10), sable (n = 7), <i>Redunca arundinum</i> (reedbuck) (n = 7), and <i>Connochaetes taurinus taurinus</i> (blue wildebeest) (n = 2) were randomly selected for morphological and molecular identification. Using a combination of both histological technique and ITS-2 rDNA marker, the following seven amphistome species were identified; <i>Leiperocotyle (L.) gretillati, Calicophoron (C.) microbothrium</i>, <i>C. raja</i>, <i>C. clavula</i>, <i>C. phillerouxi, Gigantocotyle</i> (<i>Gi</i>.) <i>symmeri</i>, and <i>Gastrothylax</i> (<i>G.</i>) <i>crumenifer</i> which are pouched amphistome species. <i>Orthocoelium dicranocoelium</i> identification was based on morphological characters only. Although the ITS-2 is a widely used marker, it may not be useful in discriminating cryptic species in the <i>Calicophoron</i> genus. <i>Orthocoelium (O.) dicranocoelium</i>, <i>G. crumenifer and L. gretillati</i> are first records in wild ruminants in Zimbabwe.