Ascaridoid nematodes of amphibians and reptiles: Ophidascaris Baylis, 1920

Abstract

The genus Ophidascaris is revised and divided into five groups of species. A key for the species groups is provided. Group 1 (' filaria' group) occurs in pythons and a key is provided for differentiating eight species based on fresh and preserved specimens and on developmental patterns. 0. papillifera (Linstow, 1898) is redescribed from the type-specimens and is considered to be close or identical to 0. niuginiensis, for which Candoia carinatus is recorded as a new host. A key for the differentiation of species in Groups 2 to 5 is based on preserved specimens only. Group 2 (' obconica' group) contains (i) 0. obconica and 0. trichuriformis [ = caballeroi] in South American colubrids (further investigation will probably show that 0. trichuriformis is a synonym of 0. obconica); new host records are Xenodon severus, X. neuwiedii, X. colubrinus, Leptodeira annulata, Thamnodynastes pallidus, Leimadophis poecilogyrus and Boa constrictor; (ii)O. ashi n. sp. (new species name for ' 0. labiatopapillosa' ) in North American colubrids, new host records are Nerodia valida, Heterodon nasicus and Storeria occipitomaculata; (iii) 0. mombasica in African colubrids; new host records are Psammophis phillipsii and P. sibilans; (iv) 0. solenopoion in Madagascan colubrids; (v) 0. pyrrhus in Australian elapids; new host records are Cacophis squamulosus, Cryptophis nigrescens, Demansia atra, D. olivacea, Hemiaspis signata, Hoplocephalus bitorquatus, H. stephensi, H. bungaroides and Tropedechis carinatus, it is also recorded in Australia in the colubrid Styporhyncus mairii (new host record) and in Demansia papuensis papuensis and D. olivacea papuensis in Papua New Guinea; (vi) 0. piscatori in Asian colubrids; (vii) 0. excavata [? = schikhobalovi] in Agkistrodon spp. and possibly other aquatic snakes in Asia; new host record is Agkistrodon halys blomhoffi. Group 3 (' radiosa' group) in African viperids contains 0. radiosa [= intorta] in Bitis spp. Specimens from Atheris nitschei, Causus rhombeatus and the colubrid Boaedon lineatus were similar, but showed differences indicating possibility of other species in this group. Group 4 (' najae' group) in African elapids and Asian elapids and colubrids contains 0. najae [ = daubaylisi]; new host records are Ophiophagus hannah, Boiga cyanea, Elaphe carinata. Group 5 (' arndti' group) in South American crotalids and colubrids contains 0. arndti [ = travassosi and sprenti] in Crotalus spp. and Bothrops spp.; new host record is B. atrox in Panama. No morphological differentiation except size could be detected between 0. arndti in crotalines and 0. sicki in colubrids, but in view of difference in the feeding habits of their host, both species names were tentatively sustained; new host records for 0. sicki are Xenodon neuwiedii, Leimadophis poecilogyrus, Pseudoboa cloelia, Philodryas patagoniensis and Micrurus frontalis; 0. ochoteranai was regarded as a species inquirenda.

Severe Sparganosis in Australian Tree Frogs

“…The severe bacterial infection of the L. aurea (Case 6) appeared to be acute and was presumably secondary to the invasion of spargana. Ophidascaris pyrrhus in the L. caerulea (Case 9) is a significant finding, as it is the first reported adult ascaridoid infection in an identified frog species (Barton, 1994;Sprent, 1988). This nematode undergoes extensive growth and development in subcutaneous tissues of lizards (the usual intermediate host), before being eaten by an elapid snake (the definitive host).…”

Ophidascaris wangi sp. n. and O. najae (Gedoelst, 1916) (Ascaridida: Ascaridoidea) from snakes in China

“…With a trichuriform body, lips distinctly wider than long and being parasitic in a colubrid snake in Asia, the new species appears to belong to the 'obconica' group of Sprent (1988), which currently includes the following eight species; O. ashi Sprent, 1988, O. excavata, O. mombasica Baylis, 1921, O. obconica (Baird, 1860, O. piscatori Soota et Chaturvedi, 1970, O. pyrrhus Johnston et Mawson, 1942, O. solenopoion Chabaud, 1960and O. trichuriformis Vaz, 1935, (see Sprent 1988. The details of the morphological and morphometric differences between the new species and all its congeners in the 'obconica' group of Sprent (1988), are summarised in Table 1. To our knowledge, only O. najae has been reported collected from the king rat snake Elaphe carinata.…”

“…commonly parasitise the digestive tract of various snakes (Baylis 1921, Johnston and Mawson 1942, Teixeira de Freitas 1967, 1968, Sprent 1988, Pinto et al 2010). According to Sprent (1988), Ophidascaris includes over 30 nominal species reported worldwide.…”

“…According to Sprent (1988), Ophidascaris includes over 30 nominal species reported worldwide. Of these, only five species, O. excavata Hsü et Hoeppli, 1931, O. filaria (Dujardin, 1845, O. hsuei Freitas, 1967, O. orientalis (Wang, 1965) and O. wui Freitas, 1967, have been reported from the Chinese mainland (Hsü and Hoeppli 1931, Wang 1965, Teixeira de Freitas 1968.…”

“…The gross morphology of the present ascaridid specimens collected from Elaphe carinata, especially the morphology of the lips, the presence of interlabia, the presence or absence of intestinal caecum-like structure, the absence of ventriculus and the uterus with two branches clearly indicates they should belong to Ophidascaris. Sprent (1988) reviewed Ophidascaris and divided it into five morphological groups based on the morphology of adults, host and geographical distribution.…”