Acanthoatractis xinguensis n. gen., n. sp. (Nematoda: Cosmocercoidea: Atractidae) parasite of yellow-spotted Amazon river turtle, Podocnemis unifilis Troschel (Testudines: Podocnemididae) in Brazilian Amazon.

Nematodes collected from the stomach of the yellow-spotted turtle Podocnemis unifilis Troschel, 1848 (Testudinidae) in the Brazilian state of Pará are assigned to a new genus, allocated to the family Atractidae (Cosmocerdoidea). Acanthoatractis n. gen. differs from all other genera of Atractidae based on the combination of the following morphological characters: cephalic extremity surrounded by eight bifurcated, wrench-shaped sclerotized structures arranged in a circle; oral opening encircled by two sclerotized pieces with pointed ends and a median portion with a pair of hooks; in males the larger (left) spicule is narrower in the middle third and the gubernaculum is absent. The type species, Acanthoatractis xinguensis n. gen., n. sp., has nine pairs of caudal papillae and a single papilla anterior to the cloacal lip. The new species is the seventh record of an atractid genus parasitizing P. unifilis.

New species of Serpinema (Nematoda: Camallanidae) from the scorpion mud turtle Kinosternon scorpioides (Testudines: Kinosternidae) from eastern Amazon, Brazil.

The genus Serpinema Yeh, 1960 allocates parasitic nematodes of freshwater turtles distributed across the Oriental, Neotropical, and Palearctic regions. Five of 10 valid species of the genus Serpinema occur in the Neotropical region, and three have been recorded parasitizing Kinosternon scorpioides Linnaeus, 1766. In the present work, we describe a new species of Serpinema, a gastrointestinal parasite of K. scorpioides from the Brazilian Amazon, using light and scanning electron microscopy. Serpinema pelliculatus n. sp. differs from other species of the genus by the number and distribution of caudal papillae and spicule morphology. The new species is the seventh recorded for the Neotropical region.

Vogtnema asymmetrica n. gen., n. sp. (Nematoda: Cosmocercoidea: Atractidae) parasite of Rhinoclemmys punctularia (Daudin) (Testudines: Geoemydidae) from eastern Amazon, Brazil.

Nematodes collected from the stomach and large intestine of Rhinoclemmys punctularia (Daudin) from the eastern Amazon, Brazil, are assigned to a new genus, Vogtnema n. gen., allocated in the family Atractidae (Cosmocerdoidea). Vogtnema n. gen. differs from all other genera of Atractidae based on the combination of the following morphological characters: four lips V-shaped (two subdorsal and two subventral) without sclerotized structures associated, absence of sclerotized formations and/or pieces surrounding the oral opening, oral aperture surrounded by flange internal membranous structures; in males the larger spicule is alate. The type species Vogtnema asymmetrica n. gen., n. sp. has the five precloacal pairs of papillae situated on the right side of the body that are more prominent than those on the left side. We also provide an identification key to the genera of the family Atractidae.

A new species of Rhabdias (Nematoda: Rhabdiasidae), a lung parasite of Pristimantis chiastonotus (Anura: Strabomantidae) from the Brazilian Amazon: description and phylogenetic analyses.

Rhabdias Stiles and Hassal, 1905 comprises approximately 90 species of parasitic lung nematodes of amphibians and reptiles that have a wide distribution, with 21 species occurring in the Neotropics. In the present study, we describe Rhabdias waiapi n. sp. found parasitizing the lungs of the anuran species Pristimantis chiastonotus from the Amazon Biome in the Amapá State, Northern Brazil. The new species is characterized by having an elongated body, expansions of the cuticular inflation in the anterior end that become more discrete along the body, an anterior end with a slight constriction at the level of the esophageal apex with four rounded subapical elevations of the body wall, six lips, four near the edge of the oral opening and two more distant lateral ones, and a gradually tapering elongated tail. In addition, molecular analyses and phylogenetic reconstructions were made, with sequences from the coding region of the mitochondrial cytochrome c oxidase subunit I gene. Those results strongly support the status of the new taxon, which formed a poorly supported clade with Rhabdias sp. 5 from Anolis brasiliensis from Northeast Brazil. Rhabdias waiapi n. sp. is the 19th species of the genus described in the Neotropics for amphibians, the 10th in Brazil, the second described from hosts of the family Strabomantidae from the Neotropical region, and the first amphibian nematode species described in the Amapá State.