The life cycle stages of three Diplostomum species maintained in the laboratory.

The taxonomy of Diplostomum species is in a highly confused state due to synonomy and descriptions based on only one life cycle stage. The objective of this study was to establish and maintain life cycles of several Diplostomum species in the laboratory so that accurate and detailed descriptions could be made. Metacercariae taken from the eyes of fresh water fish were identified using the key of Shigin (1986). Adopting the method of Field, McKeown & Irwin (1994) life cycles of Diplostomum spathaceum, Diplostomum parviventosum and Diplostomum volvens were established and each stage was described, measured and photographed or illustrated as required. The results of this work will provide standard descriptions for the life cycle stages of these Diplostomum species. It will relieve some of the identification difficulties experienced when only one stage in the life cycle is encountered.