Nematodes found in Nile crocodiles in the Kruger National Park,South Africa,with redescriptions of Multicaecum agile (Wedl, 1861) (Heterocheilidae) and Camallanus kaapstaadi Southwell & Kirshner, 1937 (Camallanidae)

Sixteen Nile crocodiles were collected in the Kruger National Park, South Africa and vicinity during 2010 and 2011. A total of 11 nematode species representing six families were recovered. Heterocheilids were the dominant group, comprising five species, with Dujardinascaris madagascariensis (Chabaud & Caballero, 1966) being the most prevalent (75%), followed by Ingwenascaris sprenti Junker & Mutafchiev, 2017 (68.8%), which was also the second most numerous nematode. While less prevalent (31.3%), Typhlophoros kwenae Junker & Mutafchiev, 2017 was the most abundant species. Micropleura huchzermeyeri Junker & Mutafchiev, 2017 (Micropleuridae) was collected from five crocodiles and Crocodylocapillaria sp. (Capillariidae) occurred in a single host. Three nematodes, Camallanus kaapstaadi Southwell & Kirshner, 1937, Spirocamallanus sp. (both Camallanidae) and Ascarophis sp. (Cystidicolidae), are considered accidental infections, likely ingested with the hosts’ prey. Our findings of D. dujardini (Travassos, 1920), D. madagascariensis and Multicaecum agile (Wedl, 1861) in South Africa constitute new geographical records. Crocodylocapillaria sp. represents a new host and geographical record, while T. kwenae, I. sprenti and M. huchzermeyeri have been described as new species during the course of this survey. Multicaecum agile is here redescribed based on light and scanning electron microscopy. Previously undescribed morphological characters of C. kaapstaadi, typically a parasite of Xenopus spp. (Amphibia: Pipidae), but here found in two Nile crocodiles, are also presented.

     

Redescription of Chabaudacuaria multispinosa (Pérez Vigueras, 1938) n. g., n. comb. (Nematoda: Spirurida: Acuariidae) based on specimens from Ardea herodias L. and Nyctanassa violacea (L.) (Ardeidae) in Florida

Chabaudacuaria n. g. is erected, as monotypic, for C. multispinosa (Pérez Vigueras, 1938) n. comb. (Spirurida: Acuariidae) [syns Cheilospirura multispinosa Pérez Vigueras, 1938; Acuaria multispinosa (Pérez Vigueras, 1938) Yamaguti, 1961]. This species, a parasite of various ardeid birds, is redescribed by means of light and scanning electron microscopy based on material from great blue herons Ardea herodias L. and yellow-crowned night herons Nyctanassa violacea (L.) in Florida, USA. Chabaudacuaria n. g. resembles Acuaria Bremser, 1811, Cheilospirura Diesing, 1861, Skrjabinocerca Schikhobalova, 1930 and Xenocordon Mawson, 1982 in its straight cordons which do not anastomose. However, it can be distinguished from them by the didelphic-prodelphic uterus and the absence of caudal alae in the males. In the pattern of its cordons (consisting of a row of plates and a longitudinal ridge) and the absence of an area rugosa, the new genus is similar to Chevreuxia Seurat, 1918, Syncuaria Gil??bert, 1927, Aviculariella Wehr, 1931, Skrjabinocara Kurashvili, 1940, Decorataria Sobolev, 1949 and Desportesius Chabaud & Campana, 1949, which are characterised by anastomosing cordons. The didelphic-prodelphic female reproductive system of Chabaudacuaria is intermediate between the didelphic-amphidelphic uterus of Chevreuxia and the monodelphic-prodelphic uterus of Syncuaria, Aviculariella, Skrjabinocara, Desportesius and Decorataria. Therefore, the straight and non-anastomosing cordons are considered to be autapomorphic for Chabaudacuaria.     

Description of Proyseria petterae n. sp., with an amended generic diagnosis and a review of the species of Proyseria Petter, 1959 and Stegophorus Wehr, 1934 (Nematoda: Acuariidae)

Proyseria decora (Dujardin, 1845) (the type-species of the genus Proyseria Petter, 1959) is redescribed on the basis of specimens from Alcedo atthis (L.) (Coraciiformes: Alcedinidae) from Iran. P. petterae n. sp. is described from Corythornis vintsioides (Eydoux & Gervais) (Alcedinidae) from Madagascar by light and scanning electron microscopy. Proyseria sp. from Alcedo euryzona Temminck from continental Malaysia is described on the basis of a single male specimen. Stegophorus alcedonis Puqin, Yanyin & Guocal, 1991 from A. atthis in China is transferred to the genus Proyseria as P. alcedonis n. comb. The generic diagnosis of Proyseria is amended. Review of the species of the genera Proyseria and Stegophorus Wehr, 1934 is presented.     

The erection of Pelecanema n. g. (Nematoda: Spirurida: Acuariidae), with redescriptions of P. sirry (Khalil, 1931) n. comb. and P. pelecani (Johnston & Mawson, 1942) n. comb.

Pelecanema n. g. is erected for P. sirry (Khalil, 1931) n. comb., syn. Synhimantus sirry Khalil, 1931 (type-species) and P. pelecani (Johnston & Mawson, 1942) n. comb., syn. Dispharynx pelecani Johnston & Mawson, 1942. In the structure of its cordons, consisting of two rows of delicate cuticular plates, the new genus is similar to Synhimantus Railliet, Henry & Sisoff, 1912, Dispharynx Railliet, Henry & Sisoff, 1912, Chordatortilis Machado de Mendon?a & Olivera de Rodrigues, 1965 and Parachordatortilis Mutafchiev, Santoro & Georgiev, 2010. Pelecanema sirry, a parasite of Pelecanus onocrotalus L. and P. crispus Bruch (Pelecaniformes, Pelecanidae) in Africa (Egypt and Senegal) and Europe (Ukraine and Bulgaria), is redescribed using light and scanning electron microscopy on the basis of specimens from P. crispus from Bulgaria. Pelecanema pelecani, a parasite of Pelecanus conspicillatus Temminck in Australia, is also redescribed using light microscopy on the basis of specimens from its type-host and type-locality. In contrast to a previous opinion recognising Pelecanema sirry and P. pelecani as synonyms, the two species are considered distinct and P. pelecani is validated.     

Trichosomoides nasalis (Nematoda: Trichinelloidea) in the murid host Arvicanthis niloticus: Migration to the epithelium of the nasal mucosa after intramuscular development

Knowledge of the biology of the trichinelloid subfamily Trichosomoidinae is poor. Trichosomoides nasalis is a common parasite of Arvicanthis niloticus (Muridae) in Senegal, and a procedure for experimental infections has been established. It has been demonstrated that larvae develop in striated muscle fibres, similar to Trichinella spp., but they are not arrested in the first stage, and they reach the adult stage within three weeks. In the present histological study it is shown that T. nasalis females and dwarf males migrate from the abdomen and thorax to the host’s muzzle, moving through connective tissues and between muscles. A few migrating specimens were also found in the blood vessels of the nasal mucosa. While sexes were still separated in the lamina propria of the mucosa, females recovered from the epithelium contained intra-uterine males. Worms were found between the incisors in the mucosa of the anterior and median conchae which are rich in mucous cells. Only the pseudostratified epithelium was parasitized. Under natural conditions, the inflammation of the nasal mucosa that is induced by the parasites might reduce the competitiveness of infected rodents when foraging or looking for potential mates.     

A 28S rDNA-based phylogeny of the nematode family Acuariidae (Spirurida) parasitic in vertebrates

The aim of this study was to investigate the phylogenetic relationships of nematodes of the family Acuariidae using partial large subunit nuclear ribosomal DNA (28S) sequences of 15 genera represented by 18 species. The results confirmed the monophyly of the family Acuariidae and supported its close relationship with nematodes of the family Cystidicolidae. Two major clades were revealed within Acuariidae, one represented by nematodes of the subfamily Schistorophinae and another composed of members of the subfamilies Acuariinae and Seuratiinae. The collarette was shown to be a structure that arose several times within the clade Acuariinae–Seuratiinae. As a result, we suggest the suppression of the subfamily Seuratiinae and inclusion of its genera within the subfamily Acuariinae. Morphological characters, host ranges and life cycles of the taxa included in the analyses are discussed as well as the possible relationships of remaining acuariid genera within the revealed subclades. Additionally, we propose an amended generic diagnosis of Syncuaria Gilbert, 1927 to accommodate Syncuaria sagittata (Rudolphi, 1809) n. comb. and Syncuaria longevaginata (Molin, 1860) Skrjabin, Sobolev, & Ivashkin, 1965. New host and geographic records are also presented.     

Shaking the Tree: Multi-locus Sequence Typing Usurps Current Onchocercid (Filarial Nematode) Phylogeny

During the past twenty years, a number of molecular analyses have been performed to determine the evolutionary relationships of Onchocercidae, a family of filarial nematodes encompassing several species of medical or veterinary importance. However, opportunities for broad taxonomic sampling have been scarce, and analyses were based mainly on 12S rDNA and coxI gene sequences. While being suitable for species differentiation, these mitochondrial genes cannot be used to infer phylogenetic hypotheses at higher taxonomic levels. In the present study, 48 species, representing seven of eight subfamilies within the Onchocercidae, were sampled and sequences of seven gene loci (nuclear and mitochondrial) analysed, resulting in the hitherto largest molecular phylogenetic investigation into this family. Although our data support the current hypothesis that the Oswaldofilariinae, Waltonellinae and Icosiellinae subfamilies separated early from the remaining onchocercids, Setariinae was recovered as a well separated clade. Dirofilaria, Loxodontofilaria and Onchocerca constituted a strongly supported clade despite belonging to different subfamilies (Onchocercinae and Dirofilariinae). Finally, the separation between Splendidofilariinae, Dirofilariinae and Onchocercinae will have to be reconsidered.     

Two new species of Quasithelazia Maplestone, 1932 (Nematoda: Acuariidae) from Malaysia,with an amended diagnosis and review of the genus

Quazithelazia rostrata n. sp. from Ceyx erithaca (L.) (type-host) and Alcedo euryzona Temminck (Coraciiformes, Alcedinidae) and Q. alata n. sp. from Enicurus ruficapillus Temminck (Passeriformes, Muscicapidae) are described from vicinities of Gombak Biological Station, Selangor, Malaysia; both species are parasitic under the koilin lining of the gizzard. Paratypes of Schistogendra pelargopsis Nandi, De & Majumdar, 1985, a parasite of Pelargopsis capensis (L.) (Alcedinidae) from India, are redescribed and the species is recognised as a junior synonym of the type-species of Quasithelazia, Q. tenuis Maplestone, 1932 (new synonymy), a species originally described from Halcyon smyrnensis (L.) (Alcedinidae) in India. An amended diagnosis of the genus Quasithelazia Maplestone, 1932 is proposed. Currently, this genus includes eight species occurring in the Old World, six of them parasitic in kingfishers (Alcedinidae) and two species parasitic in flycatchers (Muscicapidae). These include, inter alia, Q. halcyoni n. comb. for Viktorocara halcyoni Ryzhikov & Khokhlova, 1964 from Halcyon smyrnensis and H. pileata (Boddaert) in Vietnam and the Russian Far East, Q. microcordonis n. comb. for Rusguniella microcordonis Schmidt & Kuntz, 1971 from Halcyon coromanda major (Temminck & Schlegel) in Taiwan and Q. multipapillata n. comb. for Schistogendra multipapillata Zhang, 1993 from Tarsiger cyanurus (Pallas) (Muscicapidae) in China. Comparative morphological data for Quasithelazia spp. are presented. Schistogendra oligopapillata Zhang & An, 2002 from domestic ducks in China is considered a species incertae sedis.     

Parachordatortilis n. g. (Nematoda: Spirurida: Acuariidae), with a redescription of P.mathevossianae (Petrov & Chertkova, 1950) n. comb., a parasite of Falco tinnunculus L. (Aves: Falconiformes)

Parachordatortilis n. g. is proposed as a monotypic genus for Parachordatortilis mathevossianae (Petrov & Chertkova, 1950) n. comb. (Spirurida, Acuariidae), previously Dispharynx mathevossianae Petrov & Chertkova, 1950. The new genus can be distinguished from all other acuariid genera by having cordons with a sinistral torsion. Parachordatortilis possesses cordons consisting of two rows of delicate cuticular plates delimiting a longitudinal canal. This pattern of cordon structure suggests that Parachordatortilis is closely related to Dispharynx Railliet, Henry & Sisoff, 1912, Synhimantus Railliet, Henry & Sisoff, 1912 and Chordatortilis Machado de Mendon?a & Olivera de Rodrigues, 1985. P. mathevossianae is redescribed on the basis of light and scanning electron microscopical observations of specimens collected from a common kestrel Falco tinnunculus L. in southern Italy.