Biogeography of Parasitic Nematode Communities in the Galápagos Giant Tortoise: Implications for Conservation Management.

The Galápagos giant tortoise is an icon of the unique, endemic biodiversity of Galápagos, but little is known of its parasitic fauna. We assessed the diversity of parasitic nematode communities and their spatial distributions within four wild tortoise populations comprising three species across three Galápagos islands, and consider their implication for Galápagos tortoise conservation programmes. Coprological examinations revealed nematode eggs to be common, with more than 80% of tortoises infected within each wild population. Faecal samples from tortoises within captive breeding centres on Santa Cruz, Isabela and San Cristobal islands also were examined. Five different nematode egg types were identified: oxyuroid, ascarid, trichurid and two types of strongyle. Sequencing of the 18S small-subunit ribosomal RNA gene from adult nematodes passed with faeces identified novel sequences indicative of rhabditid and ascaridid species. In the wild, the composition of nematode communities varied according to tortoise species, which co-varied with island, but nematode diversity and abundance were reduced or altered in captive-reared animals. Evolutionary and ecological factors are likely responsible for the variation in nematode distributions in the wild. This possible species/island-parasite co-evolution has not been considered previously for Galápagos tortoises. We recommend that conservation efforts, such as the current Galápagos tortoise captive breeding/rearing and release programme, be managed with respect to parasite biogeography and host-parasite co-evolutionary processes in addition to the biogeography of the host.

Pneumonia from Angiostrongylus vasorum infection in a red panda (Ailurus fulgens fulgens).

A 9-year-old, male, captive red panda (Ailurus fulgens fulgens) in an urban zoo in the United Kingdom presented with respiratory distress and weight loss. The animal was euthanatized, and a postmortem examination was performed. The lungs were diffusely consolidated with extensive mineralization. Microscopically, there was extensive obliteration of normal pulmonary architecture by sheets and coalescing nodules of partially mineralized fibrous tissue and granulomatous inflammation centered on large numbers of nematode larvae and eggs. First stage nematode larvae were isolated from lung tissue and were characterized as Angiostrongylus vasorum on the basis of their morphology and sequencing of the 18S ribosomal RNA gene and the entire second internal transcribed spacer. Although A. vasorum has previously been reported in red pandas in a zoological collection in Denmark, this study is the first reported case in the United Kingdom and occurs against a background of geographical spread and increased incidence of disease in domestic and wild canids. Angiostrongylus vasorum should be considered a differential diagnosis for respiratory disease in the red panda and taken into account when planning parasite and pest control programs for zoological collections.

Ovejector structure in the Haemonchinae (Nematoda:Trichostrongyloidea) of ruminants.

The use of ovejector structure in the phylogeny of the Haemonchinae is hampered by differences among nematologists in the application of terminology and the recognition of homologous parts. Some workers recognize a sphincter with 2 parts, but others recognize only the proximal, rounded part of the sphincter and include the distal cylindrical part of the sphincter with the vestibule. The results of this study demonstrate that all sphincters of Haemonchinae of ruminants have 2 parts. To encourage the application of a uniform terminology to homologous parts of the ovejector, we propose the use of the terms "sphincter 1" for the rounded part and "sphincter 2" for the cylindrical part. It is hoped that clarification of the terminology for ovejectors of the Haemonchinae will provide a model useful for improving descriptions of ovejectors throughout the Trichostrongyloidea.

Redescriptions of Haemonchus mitchelli and Haemonchus okapiae (Nematoda: Trichostrongyloidea) and description of a unique synlophe for the haemonchinae.

In the course of a revision of Haemonchus Cobb, 1898 (Nematoda), commonly referred to as large stomach worms, significant new morphological information was discovered that allows the recognition of 2 species believed for more than 50 yr to be synonymous. Both species, Haemonchus mitchelli Le Roux, 1929, from the eland Taurotragus oryx and other African ruminants and H. okapiae van den Berghe, 1937, from the okapi Okapia johnstoni, have a synlophe of 42 ridges, but the synlophe of H. mitchelli is longer than that of H. okapiae. The distal tip of the left spicule of H. mitchelli bears a barb that is about twice as long as the short barb and half as long as the long barb on the right spicule. In contrast, the barb on the left spicule of H. okapiae is similar in size to the short barb and about 25% as long as the long barb of the right spicule. The dorsal ray of H. mitchelli is bifurcated distally for 25-39% (32%) of its length and its stem is expanded proximally, but the dorsal ray of H. okapiae is bifurcated 37-50% (42%) and its stem is of uniform thickness.

Cylicocyclus asini n. sp. (Nematoda: Cyathostominae) from donkeys Equus asinus in South Africa.

Cylicocyclus asini n. sp. is described from the ventral colons of seven domesticated donkeys Equus asinus in South Africa. The specimens are smaller than 11 members of the genus Cylicocyclus, which currently comprises 10 recognised species, one recognised subspecies and two species inquirendae, but is similar in size to the two smaller species, C. ashworthi and C. leptostomum. Additionally, the small size of its buccal capsule places it within the so-called small buccal capsule group, namely C. ashworthi, C. leptostomum, C. nassatus, C. radiatus and C. triramosus. The shape of the oesophagus at the oesophago-intestinal junction is elongate, similar to that of C. leptostomum. The female specimens have a tail length shorter than the vulva to anus distance, similar to three of the smaller Cylicocyclus species, namely C. leptostomum, C. radiatus and C. triramosus. The new species is distinguished from the smaller members of the genus by the presence of a 'club-foot' posterior in the female specimens, 40-46 elements in the external leaf-crown and a deep division of the dorsal ray which extends beyond the origin of the externodorsal ray. Similarly, the new species can be separated from the two other members in the genus with a 'club-foot' posterior in the females (C. auriculatus and C. gyalocephaloides) by its body length (6.6-8.47 mm) and the presence of a nipple-like dorsal gutter.

Paraorientatractis semiannulata n. g., n. sp. (Cosmocercoidea: Atractidae) from the large intestine of the side-necked turtle, Podocnemis unifilis Troschel, 1848 (Testudines: Pelomedusidae) in Brazil

Specimens collected from the large intestine of the side-necked turtle Podocnemis unifilis Troschel, 1848, in the region of Cumina and Trombetas rivers near Para, Brazil are assigned to a new genus and Paraorientatracti semiannulata. The new genus is separated from the nearest genus Orientatractis by the funnel-shaped mouth opening, the presence of 4 distinct lips, 4 papillae in the internal cycle, one on each lip margin, 2 lateral amphids with large amphidial pores and absence of submedian papillae. It is also separated from Orientatractis and Proatractis by the presence of striated lateral alae which curve dorsally extending from mid oesophagus to mid tail, the difference in size of the vulvar opening and the presence of large transverse ridges or semiannules on the dorsal surface. The new species can be separated from the species of the genera Orientatractis and Proatractis by the characters that distinguish the genera and the arrangement of the caudal papillae on the male. A host/parasite list for Podocnemis spp. is included.