The taxonomy of Capillaria spp. (Nematoda: Trichuroidea) in carnivorous mammals from Ontario,Canada

Summary Four species of Capillaria were found in eight species of wild carnivorous mammals (286 carcasses) taken in Ontario, Canada. C. plica was found in the urinary bladder of raccoon (Procyon lotor), red fox (Vulpes vulpes), coyote (Canis latrans), fisher (Martes pennanti) and striped skunk (Mephitis mephitis); C. putorii in the stomach and intestine of short-tailed weasel (Mustela erminea), mink (M. vison), fisher, marten (Martes americana), striped skunk and raccoon; C. aerophila in the mucosa of the trachea and bronchi of red fox and marten and C. procyonis in the epithelial lining of the oesophagus of raccoon and striped skunk. All four Capillaria spp. are redescribed and specimens of each species from different host species are compared. A key to the identification of the above species as well as C. didelphis and C. hepatica is presented. Specimens of C. erinacei and additional material of C. putorii were obtained on loan. Specimens named C. mustelorum by previous authors were collected from carnivores in Ontario. C. mustelorum and C. erinacei are considered to be synonyms of C. putorii. The genus Capillaria is briefly reviewed historically and the recognition of other genera, based on single characters, is discussed and rejected. The possibility of accommodating the Capillaria spp. from Canadian carnivorous mammals in the sub-genera Capillaria and Thominx is discussed and dismissed. ac]19791022     

Pseudocapillaria (Discocapillaria) margolisi n. subg., n. sp. (Nematoda: Trichuroidea) from freshwater fishes of West Bengal,India

A new nematode,Pseudocapillaria (Discocapillaria) margolisi n. subg., n. sp., from the freshwater fishesPuntius conchonius, P. sophore andAmblypharyngodon mola of West Bengal, India is described. The presence of a ventral lobe-like elevation with two papillae and the absence of a dorsal cuticular membrane on the male tail are referred to as distinguishing features of the new subgenus. The parasite is also characterised by small body size, short and non-annulated stichocytes, a distinctly expanded and folded lobular rim of the proximal end of the spicule, and eggs with protruding polar plugs, all features in which it differs distinctly from other species of the genusPseudocapillaria.     

New information on the location of Capillaria procyonis (Nematoda: Trichuroidea) in the tongue of a raccoon (Procyon lotor)

Histologic examination of the tongue of one juvenile male raccoon demonstrated the presence of adults and unembryonated eggs of the nematode Capillaria procyonis within parasite-induced tunnels in the stratified squamous epithelium. There was no inflammatory infiltrate within the epithelium or the subjacent lamina propria. The shape of tunnels approximated that of the resident nematodes and were lined by flattened and attenuated epithelial cells. Therefore, the site of infection of C. procyonis in the raccoon includes the oral, lingual and pharyngeal epithelium in addition to the esophagus.     

Hysterothylacium patagonense n. sp. (Nematoda: Anisakidae) from freshwater fishes in Patagonia,Argentina, with a key to the species of Hysterothylacium in American freshwater fishes

A new anisakid nematode, Hysterothylacium patagonense n. sp., is described from the intestine of the temperate bass Percichthys trucha (Cuvier & Valenciennes), a freshwater fish from Lake Aluminé, Patagonia, Argentina. It is characterised mainly by the absence of lateral alae, the length ratio of the caecum and ventricular appendix (1:0.9–1.8), the length of the spicules (0.952–1.292 mm) and the presence of minute spines on the tip of the tail. In the same locality and in Lake Huechulafquen, advanced third-stage and fourth-stage larvae of this parasite were also recorded from the digestive tract of the introduced salmonids, Salvelinus fontinalis (Mitchell), Oncorhynchus mykiss (Walbaum) and Salmo trutta L. This is the second Hysterothylacium species described from freshwater fishes in South America. A key to Hysterothylacium species parasitising American freshwater fishes is provided.     

The geographic distribution and host range of Capillaria hepatica (Bancroft) (Nematoda) in Australia.

The geographic distribution, host range and prevalence of Capillaria hepatica were recorded in 4629 house mice, Mus domesticus, 263 black rats, Rattus rattus, and 58 Norway rats, R. norvegicus. The parasite was found at five localities, all in or near large towns along the coast. The two Rattus species appeared to be the primary hosts of C. hepatica in Australia. Published and unpublished data on helminth infections of Australian native mammals from 1162 murids (26 species), 3018 marsupials (67 species) and 99 monotremes (two species) were compiled. Only seven animals from three murid species were infected with C. hepatica; all were from the same rainforest in northern Queensland. C. hepatica was distributed widely, occurring in the house mouse, black rat and Norway rat on a 10,850 ha farm but there was no infection in cattle, sheep or goats (abattoir records). Also, 52 rabbits, four cats and one fox (shot samples) and 27 marsupial mice, Sminthopsis crassicaudata (museum specimens), had no sign of C. hepatica infection. Overall, the results indicate that transmission of C. hepatica to native, domestic and feral mammals is rare, presumably because of ecological constraints on egg embryonation and survival. In the light of these findings, the potential use of C. hepatica as a biological agent to control mouse plagues in Australia is discussed.     

Resource tracking in North American Telorchis spp. (Digenea: Plagiorchiformes: Telorchidae)

We examine the evolution of host specificity for species of Telorchis, using the methods developed by researchers studying phytophagous insect-plant systems. Optimization of "generalist" compared with "specialist" onto the phylogeny for Telorchis revealed ambiguous patterns, depending on how the 2 terms were defined. Regardless of that definition, most of the evolutionary diversification of this group has been carried out within eucryptodiran turtles, the ancestral host group. From that plesiomorphic background, there appears to have been 2 episodes of specialization by way of a host switch into caudates (ancestor of T. stunkardi + T. sirenis) and snakes (T. auridistomi), and 1 episode of exuberant expansion producing a true generalist (T. corti). These results, which indicate that most species of Telorchis are tracking widespread plesiomorphic resources, mirror those reported for phytophagous insects and their plants. We believe that establishing a dialogue between the two research groups will be mutually beneficial to both and will strengthen our understanding of the complex factors underlying the evolution of coevolutionary associations.     

Similascarophis n. gen. n. spp. (Nematoda: Cystidicolidae) parasitizing marine fishes off the Chilean coast

Similascarophis (Cystidicolidae) n. gen. is proposed. In the mouth of specimens of this genus, submedial labia are absent and pseudolabia do not have any part projecting toward the central oral opening. These nematodes were obtained from the alimentary tract of 7 marine fish species along the coast of Chile: Bovichthys chilensis Regan, Eleginops maclovinus (Cuvier), Pinguipes chilensis (Valenciennes), Cilus gilberti (Abbott), Cheilodactylus variegatus Valenciennes, Girella laevifrons (Tschudi), and Graus nigra Philippi. Morphology and morphometry are compared between 2 new Similascarophis species: Similascarophis maulensis n. sp. and S. chilensis n. sp., which differ in the presence of sublabia and in the length of the glandular esophagus and left spicule. We also recorded Similascarophis sp. in 2 other host species, which showed some distinct proportional measurements, although these differences were not sufficiently clear to identify them as a new species.     

Achene structure and taxonomy of North American Bolboschoenus (Cyperaceae)

Surface and transverse section achene structures ofBolboschoenus maritimus, B. robustus, B. fluviatilis, B. novae-angliae, B. glaucus, and the putative hybridsB. maritimus × B. rubustus andB. glaucus × B. maritimus from North America are described and illustrated with SEM micrographs. The same three type of pericarp structure reported by Browning and Gordon-Gray (1993) from southern Africa were found except that the “type 2” (B. glaucus) was not matched precisely. Intermediate achene structures and other evidence support both the hybrid origin ofB. novae-angliae (=B. fluviatilis × B. robustus) and hybridization betweenB. glaucus andB. maritimus. The new combinationBolboschoenus novae-angliae is made.     

Dujardinascaris spp. (Nematoda: Ascaridoidea) in Old World crocodilians

Five new species of the genus Dujardinascaris Baylis, 1947 are described from Old World crocodilians: D. petterae n. sp. in Osteolaemus tetraspis from the Congo, Central Africa; D. blairi n. sp in Crocodylus johnstoni from Northern Australia; D. harrisae n. sp., D. angusae n. sp., and D. westonae n. sp. in C. porosus from Papua New Guinea. The species are differentiated by the relative length of the spicules, the shape of the gubernaculum and the form of the male tail. Females of the species cannot be readily distinguished morphologically.     

Paracapillaria xenentodoni n. sp. (Nematoda: Trichuroidea) from the fishXenentodon cancila (Hamilton) from West Bengal,India

A new nematode,Paracapillaria xenentodoni n. sp. is described based on light microscope studies of the worms recovered from the migratory fishXenentodon cancila (Hamilton) from the Hooghly estuary at Kalyani, West Bengal, India. The worms are characterised by relatively large body size, the structure of the male caudal extremity (the presence of two wide, lobe-like, dorso-lateral caudal projections), the large size of the spicule (0.236–0.374 mm), the transversely wrinkled but non-spiny spicular sheath, the structure of the stichosome (30–40 stichocytes present), the slightly elevated anterior vulval lip, and the size (0.040–0.049 × 0.021–0.026 mm) and structure of the eggs. This represents the first species of the genusParacapillaria from India and also from fishes of the family Belonidae (Atheriniformes).