Heterophyes nocens Onji & Nishio, 1916 (Digenea: Heterophyidae) from the water rat,Hydromys chrysogaster Geoffroy, 1804 in Australia

A Heterophyes species from the small intestine of the water rat, Hydromys chrysogaster, in Australia is described in detail. The specimens are assigned to H. nocens, a species which many authors believed to be a synonym of H. heterophyes. From this study, H. nocens is considered a valid species as it differs from H. heterophyes in the number of sclerites on the gonotyl, the course of the uterus, coefficients of allometric growth of the suckers and the presence of genital sinus spines.     

Baiohelmins elegans n. g., n. sp. (Digenea: Nanophyetidae) from the Australian water rat,Hydromys chrysogaster

A new genus and species of nanophyetid,Baiohelmins elegans, is described from the intestine of the Australian water rat,Hydromys chrysogaster Geoffroy, 1804 in North Queensland. The new genus differs from previously described forms by the combination of the following characters: vitelline follicles restricted to a small group posterior to each testis, cirrus pouch present and caeca not extending posterior to the ventral sucker.     

Characterization of polymorphic microsatellite markers in the water rat (Hydromys chrysogaster)

The water rat (Hydromys chrysogaster) is well adapted to a semiaquatic life and is endemic to dispersed regions of Australia and New Guinea. To analyse the genetic diversity of water rat populations, polymorphic microsatellite markers were developed. A partial genomic library was screened for microsatellite sequences. Following isolation of the microsatellite sequences, primers were designed to amplify seven loci and of these loci, five were polymorphic. The sample tested for polymorphisms came from areas across Australia and New Guinea. Between three and 13 alleles were detected for each locus. In addition the primers amplified two loci in Mus musculus and Rattus rattus.     

Quantitative estimation of islet tissue of pancreas in water rat (Hydromys chrysogaster)

Pancreases from three male and three female adult water rats ( Hydromys chrysogaster ) were studied. Estimations of islet tissue mass and of individual cell types were made on paraffin sections of Bouin-fixed tissue taken from head, neck, body and tail regions of the pancreas of each animal. Islet tissue mass was assessed using a linear scanning technique (Carpenter & Lazarow, 1962) on sections stained with haematoxylin and eosin. Specific cell types were assessed using a point-intercept method (Weibel, Kistler & Scherle, 1966) on sections stained with aldehyde-fuchsin for beta (β) cells, phosphotungstic acid haematoxylin for alpha (α) cells and an immunoperoxidase method for somatostatin for delta ( δ ) cells. Positive regional differences noted were a greater percentage proportion of islet tissue in the tail region and a lower proportion of a cells in the head region. Alpha cells were peripherally situated in the islets.
These results show some elements of agreement with a previously proposed hypothesis (Bonner-Weir & Weir, 1979) regarding the general pattern of arrangement of the mammalian endocrine pancreas.     

The Pacific Notocotylus atlanticus (Digenea: Notocotylidae)

Recently two unidentified Notocotylus species have been recovered from a mallard in Hokkaido, Japan. Preliminary data indicated that one of them may belong to N. atlanticus—a species found in Europe and on the Atlantic coast of North America. Now we have sequenced partial cox1 for several European N. atlanticus isolates and performed a barcode gap analysis. It has shown the conspecificity of European and Japanese worms, bringing up discussion on distribution, transmission and host specificity in this species.     

Coryphogonimus aglaos n. g., n. sp. (Digenea: Prosthogonimidae) from the Australian bush rat,Rattus fuscipes (Rodentia: Muridae), with notes on other prosthogonimids from Australian mammals

Coryphogonimus aglaos n. g., n. sp. (Digenea: Prosthogonimidae) is described from the liver of the Australian bush rat, Rattus fuscipes (Rodentia: Muridae). The new genus is distinguished from other prosthogonimids by the possession of the following combination of characters: oral and ventral suckers well developed; caeca terminating in front of testes; genital pore opening dorsal to oral sucker; vitelline follicles restricted to caecal region; uterus extending posterior to testes; and uterus without an egg reservoir. A single specimen of an as yet undetermined Coryphogonimus species is recorded from the Australian water rat, Hydromys chrysogaster (Rodentia: Muridae). A new host, Sminthopsis macroura (Marsupialia: Dasyuridae), is recorded for Coelomotrema antechinomes. Attention is drawn to the apparent rarity of the six known mammal prosthogonimids.     

Five new didymozoid trematodes (Platyhelminthes, Digenea) from Australian platycephalid fishes

Five new didymozoid trematodes are described from two species of platycephalid fish collected in Moreton Bay. Australia. Indodidymozoon moretonensis sp. n. from the buccal cavity and branchial arches and 1. suttiei sp. n. from the flesh are described from Platycephalus fuscus. Indodidymozoon lesteri sp. n. from the belly skin. I. pearsoni sp. n. from the eye, and Helicodidymozoon tortor gen. n., sp. n. from the buccal cavity. branchial arches and operculum are described from Platycephalus endrachtensis. The taxonomic composition of the genus Didymozoon is discussed. Five species. D. branchiale. D. brevicolle, D. koti, D. musculi and D. Platycephali are moved to Indodidymozoon ; the generic diagnosis of Indodidymozoon is revised. One species. D. spirale , and one species from Neometadidymozoon, N. helicis. are moved to the newly creeted Helicodidymozoon. Helicodidymozoon differs from Didymozoon, Indodidymozoon and metadidymozoon in the structure of the hindbody which is spirally twisted.     

Notocotylus ikutai n. sp. (Digenea: Notocotylidae) from lymnaeid snails and anatid birds in Hokkaido,Japan

An unknown species of the genus Notocotylus (Digenea: Notocotylidae) was found as the larval stage from the lymnaeid snail, Radix auricularia, in a static water area of the Chubetsu River, Hokkaido, the northernmost island of Japan. A DNA barcoding identification system was applied to detect the adult stage. Through the inspection of anatid game birds in Hokkaido, Anas crecca, Anas platyrhynchos, Anas zonorhyncha, and Mareca penelope were demonstrated to serve as the definitive hosts. The detailed morphological features of the species were characterized using adults raised experimentally in immunosuppressed mice and naturally developed larvae in R. auricularia. Although the species is morphologically similar to Notocotylus attenuatus and Notocotylus magniovatus in both adult and larval stages, its taxonomic independence was confirmed by a comprehensive study based on molecular phylogeny, morphology, and ecology. Here we propose Notocotylus ikutai n. sp. for this species. The migratory behavior of the anatid hosts and the North-Eurasian distribution of R. auricularia suggest that the new species is widely distributed in the northern Far East.     

Taxonomy of Mesostephanus Lutz, 1935 (Digenea: Cyathocotylidae) in some Australian water birds

Mesostephanus scottae n. sp. is described from Phalacrocorax sulcirostris (little black cormorant) and P. varius (pied cormorant), and M. pelecani n. sp. is described from Pelecanus conspicillatus (Australian pelican), both from Queensland, Australia. The new species are distinguishable through a combination of features: the possession and size of their ventral suckers; the size of their oral suckers; the relative development of their hindbodies; and the size of their eggs and cirrus-sacs. M. haliasturis is recorded experimentally from Phalacrocorax sulcirostris and P. varius. Sporocysts, cercariae and metacercariae of M. haliasturis are described. Sporocysts produce daughter-sporocysts, cercariae and miracidia.Mr Jacques Beuret sadly died before this paper was finalised.Mr Jacques Beuret sadly died before this paper was finalised.     

Das nervensystem der cercarie von Catatropis indica srivastava, 1935 (Digenea : Notocotylidae) und der geschlechtsreifen form von Diaschistorchis multitesticularis Rohde, 1962 (Digenea : Pronocephalidae)

The nervous systems of the cercaria of Catatropis indica and of the adult Diaschistorchis multitesticularis are described. Ganglion cells, myoblasts and large cells of unknown nature in Diaschistorchis are described and figured.

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Für technische Hilfe danke ich Miss Lilian Liz, Mr. Teh Kox Leng und Mr. K. Balakrishnan. Durchgeführt im Zoology Department, University of Malaya, Kuala Lumpur, mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Insights into the development of Notocotylus attenuatus (Digenea: Notocotylidae) in Lymnaea stagnalis: from mother sporocyst to cercariae

Notocotylus attenuatus (Digenea: Notocotylidae) is a monostome fluke parasitizing the intestinal caeca of waterfowl that uses an injection apparatus to infect its intermediate snail host. Morphology of the invading larva (a sporocyst), and the intramolluscan larval development of this fluke have not been characterized extensively. In this study, experimental infections of Lymnaea stagnalis using N. attenuatus eggs resulted in the development of sporocysts containing one germ ball or mother redia between 12 and 21 days post exposure (p.e.) within the hepatopancreas. Independent mother rediae and developing daughter rediae were present between day 25 and day 42 p.e. Cercariae, within the body of rediae, were detected 42 days p.e. The development of daughter rediae and cercariae started posteriorly in the body of parent redia and these larvae migrated anteriorly during development towards the birth pore. A cercaria was also observed emerging from the birth pore and released cercariae maturated further within the snail hepatopancreas prior to leaving the snail. The intramolluscan development was completed 45 days p.e. when the first fully formed cercariae were shed into the outer environment. These data detail the fascinating post-embryonic development of N. attenuatus and highlight the intricate nature of larval transitions within its snail host.     

Brachylaima apoplania n. sp. (Digenea: Brachylaimidae) from the Polynesian rat, Rattus exulans (Rodentia: Muridae), in New Zealand: origins and zoogeography

Brachylaima apoplania n. sp. is described from the small intestine of the Polynesian rat (Rattus exulans) on Tiritiri Matangi Island, New Zealand. The new species is most similar to Brachylaima ratti Baugh, 1962, from Rattus rattus. The two species differ only in morphometric characters, B. apoplania possessing significantly smaller suckers, pharynx, testes, ovary, and cirrus sac. The close resemblance between B. apoplania and B. ratti, the close relationship between their hosts, and archaeological evidence on the origin and early dispersal of R. exulans are used to hypothesize a common Southeast Asian origin for the 2 Brachylaima species. Brachylaima apoplania is believed to have dispersed subsequently throughout the South Pacific islands, along with its rodent host, in the canoes of the ancestors of the modern Polynesians and Maoris.     

Catatropis hatcheri n. sp. (Digenea: Notocotylidae) from Heleobia hatcheri (Prosobranchia: Hydrobiidae) and notes on its life-cycle in Patagonia, Argentina

A new species of Catatropis Oghner, 1905 from a freshwater Neotropical prosobranch snail, Heleobia hatcheri (Hydrobiidae), is described. Naturally infected snails were collected from Nahuel Huapí Lake in Andean Patagonia. The characteristics of the larval stages are also presented. Experimental adults were recovered from the distal region of the intestinal caeca of chicks and ducklings and natural adults from a wild duck Anas platyrhynchos. Adults of Catatropis hatcheri n. sp. can be distinguished from all other species of the genus in having 10-12 (11) ventral glands in each lateral row, the cirrus-sac extending back to between the first third and the middle of the body, the metraterm shorter than the cirrus-sac, a previtelline field of 1,258-1,544 (1,396), vitelline follicles reach back to the anterior border of the testes with some follicles extending slightly lateral to them, only external testicular margin lobed and genital pore in median line just posterior to the intestinal bifurcation. In addition, the eggs have one filament on each pole, the rediae contain one or two mature cercariae, and the cercariae are tri-oculate, with a long tail and encyst in the environment.     

Opistholobetines (Digenea: Opecoelidae) in Australian tetraodontiform fishes

Opistholebetine opecoelids are reported following examination of 1,041 individual tetraodontiform fishes, comprising 60 species and seven families, collected in Australian waters between 1986 and 2018. Nine species consistent with Opistholebes Nicoll, 1915, Heterolebes Ozaki, 1935 or Maculifer Nicoll, 1915 were recovered. However, phylogenetic analysis of sequence data, generated for some of these species, suggested that five genera, not three, are required to adequately accommodate these taxa. Thus, the concept and composition for each is revised, Pseudoheterolebes Yamaguti, 1959 nec Gupta, 1968 is resurrected and Parallelolebes n. g. is proposed. Of the nine species examined, five are new. Four new species are from fishes endemic to subtropical and temperate Australian waters for which no trematodes have previously been reported: Pa. australis n. sp. and Ps. corazonae n. sp. from the slender-spined porcupinefish Diodon nicthemerus Cuvier (Diodontidae) off Stanley, Tasmania; Pa. virilis n. sp. from the horse-shoe leatherjacket Meuschenia hippocrepis (Quoy & Gaimard) (Monacanthidae) off Stanley; and Ps. stellaglobulus n. sp. from the threebar pocupinefish Dicotylichthys punctulatus Kaup (Diodontidae) in Moreton Bay, south-east Queensland. The fifth new species is M. diodontis n. sp., collected from the spotted porcupinefish Diodon hystrix Linnaeus and the blackblotched porcupinefish D. liturosus Shaw, in tropical waters on the Great Barrier Reef. Species reported previously include the type-species of Opistholebes, O. amplicoelus Nicoll, 1915 from the rough golden puffer Lagocephalus lunaris (Bloch & Schneider) (Tetraodontidae) and the common toadfish Tetractenos hamiltoni (Richardson) (Tetraodontidae) in Moreton Bay, and three species reported for the first time from fishes in Australian waters: H. maculosus Ozaki, 1935, Pa. elongatus Ozaki, 1937 n. comb. and Ps. diodontis (Cable, 1956) n. comb., each from both D. hystrix and D. liturosus on the Great Barrier Reef. Following the revisions, Opistholebes is recognised for two species, Heterolebes for five, Maculifer for eight, Pseudoheterolebes for five and Parallelolebes for three.     

Catatropis hatcheri n. sp. (Digenea: Notocotylidae) from Heleobia hatcheri (Prosobranchia: Hydrobiidae) and notes on its life-cycle in Patagonia, Argentina

A new species of Catatropis Oghner, 1905 from a freshwater Neotropical prosobranch snail, Heleobia hatcheri (Hydrobiidae), is described. Naturally infected snails were collected from Nahuel Huapí Lake in Andean Patagonia. The characteristics of the larval stages are also presented. Experimental adults were recovered from the distal region of the intestinal caeca of chicks and ducklings and natural adults from a wild duck Anas platyrhynchos. Adults of Catatropis hatcheri n. sp. can be distinguished from all other species of the genus in having 10–12 (11) ventral glands in each lateral row, the cirrus-sac extending back to between the first third and the middle of the body, the metraterm shorter than the cirrus-sac, a previtelline field of 1,258–1,544 (1,396), vitelline follicles reach back to the anterior border of the testes with some follicles extending slightly lateral to them, only external testicular margin lobed and genital pore in median line just posterior to the intestinal bifurcation. In addition, the eggs have one filament on each pole, the rediae contain one or two mature cercariae, and the cercariae are tri-oculate, with a long tail and encyst in the environment.     

Catatropis chilinae n. sp. (Digenea: Notocotylidae) from Chilina dombeiana (Gastropoda: Pulmonata) and notes on its life-cycle in Patagonia,Argentina

A new species of Catatropis from a freshwater pulmonate snail of the family Chilinidae, which is endemic to South America, is described. Naturally infected Chilina dombeiana were collected from several localities in Andean Patagonia. The characteristics of the larval stages are presented. Experimentally reared adults, located in the distal portion of the intestinal caeca, were recovered from chickens and ducks. Adults of Catatropis chilinae n. sp. can be distinguished from all other species in having 9-11 (10) ventral glands, a cirrus-sac extending between the first third and the middle of the body, a metraterm slightly shorter or equal to the cirrus-sac, vitelline follicles reaching forward to the middle of the body, lobed testes, and a genital pore closely posterior to the caecal bifurcation. Eggs bear polar filaments only at the anopercular end. Rediae have only one or two cercariae. Shed cercariae are trioculate with a long tail and encyst in the environment, and metacercariae become infective 72 hours after encystment. This species is widely distributed between 40°10 S and 43°09 S and it is the first Catatropis species recorded for the Chilinidae and for Argentina.     

Effects of copper and zinc on the life cycle of Notocotylus attenuatus (Digenea: Notocotylidae)

Evans N. A. 1982. Effects of copper and zinc on the life cycle of Notocotylus attenuatus (Digenea: Notocotylidae). International Journal for Parasitology12: 363–369. The toxicity of copper and zinc to cercariae and metacercarial cysts of Notocotylus attenuatus was extremely low. The infectivity of cysts was not reduced even after exposure to high metal concentrations (10.0 p.p.m.) for six weeks whilst the encystment of cercariae was significantly impaired only by 10.0 p.p.m. of copper and by concentrations of zinc greater than 4.0 p.p.m. Metal-induced death of cercariae occurred most frequently during their attempts to encyst. Cercarial shedding from the first intermediate host Lymnaea peregra was, in contrast, substantially reduced by even low concentrations (0.1 p.p.m.) of both metals. Water hardness had a low influence on copper and zinc toxicity.