Ascaridoid nematodes of amphibians and reptiles: Angusticaecum and Krefftascaris n.g.

Ascaridoid nematodes reported from terrestrial and freshwater chelonians are described under two monotypic genera, Angusticaecum and a new genus Krefftascaris respectively. The former genus contains A. holopterum (Rudolphi, 1819) Baylis, 1920 [synonym A. brevispiculum Chapin, 1924], reported in the natural state from testudinid and emydid tortoises in Europe, U.S.S.R., Iran, Brazil and North Africa. The latter genus contains a new species, K. parmenteri, reported from chelid freshwater turtles in Eastern Australia. It is concluded that the former is most closely related to species in other genera in terrestrial reptiles, whereas the latter is closest to Gedoelstascaris spp. in crocodilians. Host-parasite relationships over evolutionary time between ascaridoids and chelonians are discussed

Species of Typhlophoros von Linstow, 1906 (Nematoda: Ascaridoidea) in Old World crocodilians

A new species of the genus Typhlophoros von Linstow, 1906, T. spratti, is described from the freshwater crocodile Crocodylus johnstoni and the saltwater crocodile C. porosus in northern Australia. Specimens of the new species could not be compared with the type-species, T. lamellaris, as no preserved specimens of the latter species are known to exist. The new species differs from the descriptions of von Linstow (1906) and Maplestone (1930) in the number of interlabial ridges, the form of the ventriculus and absence of lateral alae. The taxonomic status and affinities of Typhlophoros are discussed

Supplementary Review Article Ascaridoid Nematodes of Sirenians—A New Species in the Senegal Manatee

Another species in the genus Heterocheilus Diesing, 1839, collected from Trichechus senegalensis, is described. It differs from H. tunicatus in possessing elongate cuticular plaques on the body surface in the oesophageal region, a cuticle-lined vestibule between mouth and oesophagus, and triangular interlabial structures. A comparison is made between specimens of H. tunicatus from T. manatus and the specimens from T. inunguis described in a previous paper (sprent, 1980)

Supplementary Review Article Ascaridoid Nematodes of Amphibians and Reptiles: Typhlophorus, Hartwichia and Trispiculascaris

Four little-known ascaridoid species occurring in crocodilians are discussed. Typhlophorus lamellaris Linstow, 1906 and Hartwichia rousseloti Chabaud & Bain, 1966 are considered to be closely related to Heterocheilus tunicatus Diesing, 1839; Porrocaecum assymmetricum Ortlepp, 1932 is transferred to Trispiculascaris together with T. trispiculascaris Skrjabin, 1916. These three genera are placed in the subfamily Heterocheilinae sensu Sprent (1980) on account of the structure of the oesophago-intestinal junction, the labial pulp and, where known, the male tail. A key to eight genera of Heterocheilinae in crocodilians is provided

Ascaridoid Nematodes of Amphibians and Reptiles: Freitasascaris N.G.

A new genus is proposed for Orneoascaris [= Amplicaecum] alata (Baylis, 1947) Le Van Hoa, 1960. The new genus is defined and differentiated from Orneoascaris by the posterior position of the vulva and by the wide cervical alae. It is differentiated from Ophidascaris by fewer postcloacal papillae and spicules less than half the length of the ejaculatory duct. From both genera alata differs in the unique form of the lips and in the more extensive U-shaped enlargement of the nucleus of the dorsal oesophageal gland. It is suggested that this species is a specialized form, possibly of neotropical origin

Studies on ascaridoid nematodes in pythons: The life-history and development of Ophidascaris moreliae in Australian pythons

Several species of Australian python, Morelia spilotes variegatus, Liasis amethystinus, L. fuscus and L. childreni, were experimentally infected with eggs of Ophidascaris moreliae and the development of the larvae described. The first moult occurred in the egg, which survived and remained infective for over 7 years in moist conditions. The first moult occurred in 12 days and the second-stage larva in the egg was infective to mice in 14-21 days. After ingestion the larvae migrated to liver and lungs and in 21 days were mainly distributed throughout the subcutaneous tissues, particularly in the neck region and behind the ears. Growth occurred to about 8 mm; the larvae attained their infectivity for pythons after 5 weeks and retained it for more than a year. The second moult was not observed but it was assumed that the third stage was infective for pythons. Development to about the same length occurred in guinea-pigs and indigenous and laboratory rats and in the bandicoot (Isoodon obesulus). In the possum (Trichosurus sp.) a more rapid growth occurred to about the same length. No growth occurred in tadpoles. After ingestion by pythons larvae migrated to the lungs, where they remained for 3 months or more, grew to a length of 45 mm and underwent the third moult. Larvae removed from the lungs and reingested by pythons returned to the lungs if they had been in the first python for less than 60 days. After this time, they remained in the stomach of the second python. During the third moult larvae underwent a marked constriction of the anterior end, moved up the trachea and became attached in the upper oesophagus as fourth-stage larvae. In mouseinfected M. spilotes the third moult occurred at 117 days at a length of 23-45 mm; fourth-stage larvae measured 34-50 mm. The fourth moult occurred in the stomach at 318 days at a length of 37-55 mm. The smallest adult specimens found were a 55 mm male and a 63 mm female. Development to the adult stage was only observed in M. spilotes variegatus. In other python species only pre-adult forms were recovered. It appeared that development may be retarded at the fourth moult during the winter. The morphology of the larvae during the five stages of development is described. It is concluded that the main growth phases are the third stage in the lungs of the python and the adult stage in the stomach of the python. Encapsulated forms were found only in the tissues of intermediate hosts. The larvae from mouse tissues emerged from the capsules during putrefaction and survived for several weeks in water