Camallanus Railliet et Henry, 1915 (Nematoda, Camallanidae) from Australian freshwater turtles with descriptions of two new species and molecular differentiation of known taxa

Abstract

AbstractTwo new species of Camallanus are described from Australian freshwater turtles. Camallanus beveridgei sp. nov. is reported from Elseya dentata in Northern Territory. It differs from other species of the genus parasitic in turtles by several characters including the shape of the median ridge in the buccal capsule and the position of the anterior pair of caudal papillae in males. Camallanus sprenti sp. nov. is reported from Elseya latisternum (type host) and Emydura krefftii in northern Queensland. It is closely related to Camallanus tuckeri, and differs from the latter species in possessing a shorter oesophagus. We summarize data on morphology, distribution and specificity of 5 known Camallanus spp. from Australian turtles and provide a key for their identification. Sequence comparison of more than 500 base pairs at the 5′ end of the nuclear 28S rDNA gene confirms the status of C. sprenti and C. beveridgei as new species. Camallanus sprenti differs from the other 4 species of Camallanus from Australian turtles by 16–59 bases (3.1–11.5%) while C. beveridgei differed from the other 4 species by 23–60 bases (4.5–11.6%). Phylogenetic analysis demonstrates close interrelationships among C. tuckeri, C. sprenti and C. beveridgei, the three species with most similar buccal capsules.