SUPPORTING EXPERIMENTAL-EVIDENCE OF HOST-SPECIFICITY AMONG SOUTHERN AFRICAN POLYSTOMES (POLYSTOMATIDAE, MONOGENEA)

Although monogeneans of anurans are generally regarded as host-specifi c, there is a lack of conclusive experimental evidence. Infection and cross-infection experiments were conducted with oncomiracidia of Polys toma australis and P. marmorati. In a series of experiments. oncomirac idia were even a choice between natural and substitute host tadpoles. Oncomiracidia of P. australis became established in substitute hosts b ut showed a preference for the natural host, whereas the oncomiracidia of P. marmorati showed a strong and statistically significant prefere nce for the natural host. The results indicated chat although the onco miracidia of southern African polystomes showed a strong preference fo r their natural hosts, not all parasites exercised the same degree of host specificity.