Camallanine Nematodes Parasitizing Endangered Freshwater Turtles from South America, with the Description of Two New Species

Abstract

Most records of camallanid species are from fish, being poorly studied in South American turtles. This paper reports several species of Camallanus and one Serpinema parasitizing freshwater turtles in Argentina. We also describe two new nematode species of Camallanus from the Chaco Side-necked turtle Acanthochelys pallidipectoris, the Hilaire´s Side-necked turtle Phrynops hilarii, and the Black Spine-neck Swamp turtle Acanthochelys spixii. These two new nematode species differ from their previously described congeners mainly in the shape of the buccal capsule, spicules, number and distribution of caudal papillae in males, and number of mucrons in females. We provide 18S rDNA sequences of the new species of Camallanus and Camallanus sp. and report interspecific distances for the Camallanus species. Further, we report C. emydidius from Trachemys dorbigni and Camallanus sp. and Serpinema sp. from Kinosternon scorpioides, constituting the first parasitological records for these turtles in Argentina. Also, C. pallidipectoris sp. nov. is the first global parasitological report for the endangered turtle A. pallidipectoris.