The Life Cycle and Morphology of Tetracerasta Blepta, Gen. Nov. Sp. Nov. And Stegodexamene Callista, Sp. Nov. (Trematoda: Lepocreadiidae) from the Long Finned Eel, Anguilla Reinhardtii Steindachner

R. Watson, (1982), Ph.D., University of Queensland, Brisbane, Queensland, Australia. 113pp.

Two new lepocreadiid digeneans, Tetracerasta blepta, gen. nov., sp. nov. and Stegodexamene callista, sp. nov. are described from the intestines of the long-finned freshwater eel, Anguilla reinhardtii, from the Brisbane River, Queensland, and the Australian bass, Macquaria novemaculeata, from the Richmond River, New South Wales, Australia.

Their life-cycles have been elucidated and completed in the laboratory. All developmental stages are described and illustrated.

Eggs from adults of these lepocreadiid species were obtained from eels. These hatched and miracidia from them injected a precocious sporocyst into uninfected laboratory-reared prosobranch gastropods, Posticobia brazier. Following two generations of rediae in the digestive gland of the snail, large ophthalmotrichocercous cercariae were produced.

The cercaria of T. blepta penetrated uninfected tadpoles of Litoria lesueuri and the gudgeons, Hypseleotris compressus and H. galii. Encystment occurred in the muscle and viscera.

The cercaria of S. callista lured fish to eat them or were inhaled. They penetrated the throat of uninfected, pond-reared rainbow fish, Nematocentris fluviatilis and uninfected perch let, Ambassis sp. Encystment occurred in the pharyngeal muscle or liver.

Adults developed in uninfected eels, Anguilla australis and A. reinhardtii, completing the life-cycles. The life-cycles and morphology of these species are compared to those of Stegodexamene anguillae Macfarlane, 1951 and other lepocreadiids.