LIFE-CYCLE OF EUPARYPHIUM-ALBUFERENSIS N. SP. (TREMATODA, ECHINOSTOMATIDAE) FROM RATS IN SPAIN

The morphology of the different life-history stages and life-cycle of Euparyphium albuferensis are described and drawn. The freshwater snail Gyraulus chinensis (Gastropoda: Planorbidae) serves as the natural an d experimental first intermediate host. This and other freshwater snai ls, such as Lymnaea truncatula, L. peregra, L. palustris and Physa acu ta, serve as second intermediate hosts. Adult worms, possessing 45 col lar spines, were obtained naturally from Rattus norvegicus and R. ratt us, and experimentally from albino rats, mice and golden hamsters. Chi ckens, ducks and pigeons were not suitable experimental definitive hos ts. E. albuferensis differs from the most closely related species, E. murinum Tubangui, 1931, in its larger body, suckers and oesophageal me asurements, in the distribution of vitelline follicles and in the morp hology of the collar spines.