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 and experimental first intermediate host. This and other freshwater snails, such as Lymnaea truncatula, L. peregra, L. palustris and Physa acuta, serve as second intermediate hosts. Adult worms, possessing 45 collar spines, were obtained naturally from Rattus norvegicus and R. rattus, and experimentally from albino rats, mice and golden hamsters. Chickens, ducks and pigeons were not suitable experimental definitive hosts. E. albuferensis differs from the most closely related species, E. murinum Tubangui, 1931, in its larger body, suckers and oesophageal measurements, in the distribution of vitelline follicles and in the morphology of the collar spines.     

Echinochasmus leopoldinae n. sp. (Trematoda: Echinostomatidae) and data on its life-cycle

The echinostomatid trematodeEchinochasmus leopoldinae n. sp. is described on the basis of adults found in the intestine of chicks and mice experimentally infected with metacercariae from the gills of the cichlid fishesCichlasoma urophthalmus andC. synspilum from the Peninsula of Yucatan.E. leopoldinae, which had previously been misidentified asE. zubedakhaname Nasir & Díaz, 1968, is characterised by the presence of 20 collar spines with one angular spine on each side and vitelline follicles confluent in the posterior part of the body. A differential diagnosis ofEchinochasmus species possessing 20 collar spines is provided, and the developmental stages (redia, cercaria, metacercaria and adult) ofE. leopoldinae are described.     

Life-cycle,delimitation and redescription of Echinostoma revolutum (Froelich, 1802) (Trematoda: Echinostomatidae)

The life-cycle of Echinostoma revolutum (Froelich, 1802) Dietz, 1909 has been completed experimentally beginning with infected snails collected at the type-locality, near Erlangen, Germany. Based on the specimens obtained, each stage of the life-cycle has been redescribed. Important taxonomic features are discussed and hitherto unknown characteristics are described. Synonyms for E. revolutum are: Fasciola revoluta Froelich, 1802; Echinostoma paraulum Dietz, 1909; E. audyi Lie & Umathevy, 1965; and E. ivaniosi Mohandas, 1973. Adults and larvae described as E. revolutum in other works are found to be identical with Echinostoma echinatum (Zeder, 1803), E. trivolvis (Cort, 1914), E. jurini (Skvortsov, 1924), E. caproni Richard, 1964, Moliniella anceps (Molin, 1859), Echinochasmus beleocephalus (Linstow, 1873) and other echinostome species. For nearly a century, incorrect morphological, biological, life-cycle and host information has been attributed to E. revolutum, and at times these data have contributed to the diagnoses of the species. Occasionally, authors actually working with E. revolutum have ascribed their results to other species. Based on extensive experimental life-cycle studies beginning with infected snails from type-localities, it is shown that (1) the first intermediate host is a lymnaeid snail; (2) the second intermediate hosts are various pulmonate and prosobranch snails, mussels, frogs and freshwater turtles; (3) the final hosts are birds; (4) E. revolutum cercariae and adults have 37 collar spines; (5) the species occurs only in Europe and Asia; (6) Cercaria echinata Siebold, 1937, Echinostoma echinatum (Zeder, 1803) and E. jurini (Skvortsov, 1924) are the closely related 37-spined allies in Europe; and (7) species specific characteristics are expressed only in the larvae and the host-parasite relationships. The adults of E. revolutum cannot be identified using morphological criteria and it is proposed that worms with 37 collar spines belonging to the genus Echinostoma and occurring in naturally infected birds in Europe and Asia be referred to an “E. revolutum group.”     

Life-cycle and biology of Sychnocotyle kholo n. g., n. sp. (Trematoda: Aspidogastrea) in Emydura macquarii (Pleurodira: Chelidae) from southern Queensland,Australia

Sychnocotyle kholo n. g., n. sp. (Aspidogastrea: Aspidogastridae) is described from the small intestine of the freshwater turtle Emydura macquarii (Pleurodira: Chelidae). The new genus is distinguished from other aspidogastrids by the possession of the following suite of characters: no cirrus-sac; no hermaphroditic duct; four rows of alveoli on the ventral disc but no prominent papillae; Laurer's canal opening to the exterior. Eggs hatched to cotylocidia within 37–41 days at 17–24 °C. The life-cycle is obligate two-host, involving a mollusc and a freshwater turtle. Juvenile forms, almost entirely single worm infections, were found in the molluscs Corbiculina sp. (Bivalvia: Corbiculidae) and Thiara balonnensis (Prosobranchia: Thiaridae). Sychnocotyle is most likely to have evolved in Australia after the separation of Gondwanaland from Laurasia 120–100 mya.     

The life cycle of Echinochasmus bagulai (Trematoda: Echinostomatidae)

The life history of Echinochasmus bagulai, an echinostomatid trematode in birds, is reported and stages in the life cycle are described. Natural infections with cercariae, which are of the gymnocephalous type, were found in the thiarid snail Thiara tuberculata. Metacercarial cysts were found in the gills of Aplocheilus panchax, Oryzias melastigma, Gambusia affinis and Channa punctata. Adults were obtained in the small intestine of Ardeola grayi. In laboratory experiements development of cercariae into infective metacercariae took 10 days in the gills of A. panchax. Mature flukes were recovered in 10 days in the small intestine of experimentally infected 1-day-old leghorn chicks. The eggs collected from the faeces of these infected chicks were incubated at 39 degrees C. The free-swimming miracidia were found on the fifth day of incubation.     

Dicrocoeliidae (Trematoda: Digenea) of Australian mammals with description of Dicrocoelium antechini n. sp., Athesmioides aiolos n. g., n. sp. and Platynosomum burrman n. sp.

Dicrocoelium antechini n. sp. is described from the bile ducts of Antechinus swainsonii and A. stuartii (Marsupialia: Dasyuridae) from New South Wales. The species differs from all others in the genus in that the caecal bifurcation is well posterior to the ventral sucker and testes. Athesmioides aiolos n. g., n. sp. is described from Rattus fuscipes and R. lutreolus from New South Wales and from R. norvegicus, R. lutreolus and Pseudomys higginsi from Tasmania (all Rodentia: Muridae). The genus Athesmioides is characterised by the presence of unilateral vitelline follicles and an undivided caecum. Platynosomum burrman n. sp. is described from Isoodon macrourus (Marsupialia: Peramelidae) from the Northern Territory. It differs from other species in a combination of characters regarding the shape of the forebody, the arrangement of the gonads, the disposition of the uterus and the size of the eggs. The taxonomic status of Platynosomum australiense (Sandars, 1958), Brachylecithum insulare Angel & Pearson, 1977 and Brachylecithum hydromyos Angel & Pearson, 1977 are summarised. Records are presented of undescribed dicrocoeliids from the marsupials Petaurus breviceps, Planigale maculata and Dasyurus hallucatus and the murids Rattus fuscipes and Melomys sp.