Origins, Diversification, and Historical Structure of the Helminth Fauna Inhabiting Neotropical Freshwater Stingrays (Potamotrygonidae)

Members of the freshwater stingray family Potamotrygonidae occur throughout the major river systems of eastern South America that empty into the Atlantic Ocean. Ichthyologists have tended to assume that the ancestor of the potamotrygonids was an Atlantic marine or euryhaline stingray that dispersed into freshwater, presumably during the last marine ingression 3-5 million years ago. The helminth parasites that inhabit potamotrygonids suggest an alternative perspective on their origin. Phylogenetic and biogeographic analysis of the helminths inhabiting potamotrygonids suggest that the hosts are derived from an ancestral Pacific urolophid stingray that was trapped in freshwater by the uplifting of the Andes beginning perhaps as early as the early Cretaceous period and ending by the mid-Miocene epoch, changing the course of the Amazon River, which previously had flowed into the Pacific Ocea

Review of \u3ci\u3ePractical Taxonomic Computing\u3c/i\u3e by Richard J. Pankhurst (Cambridge University, 1991)

Review of Practical Taxonomic Computing by Richard J. Pankhurst (Cambridge University, 1991)

Review of \u3ci\u3eConcepts in Nematode Systematics: Proceedings of an International Symposium\u3c/i\u3e held jointly with the Association of Applied Biologists, by A.R. Stone, H.M. Platt, L.F. Khalil and D.L. Hawksworth (Academic Press, 1983)

Review of Concepts in Nematode Systematics: Proceedings of an International Symposium held jointly with the Association of Applied Biologists, in Cambridge, September 2-4, 1981, by A.R. Stone, H.M. Platt, L.F. Khalil and D.L. Hawksworth (Academic Press, 1983)

\u3ci\u3eNeopronocephalus orientalis\u3c/i\u3e Sp. n. (Digenea: Pronocephalidae) and \u3ci\u3eSpirhapalum elongatum\u3c/i\u3e Rohde, Lee, and Lim, 1968 (Digenea: Spirorchiidae) from \u3ci\u3eCuora amboinensis\u3c/i\u3e (Daudin) in Malaysia

Neopronocephalus orientalis from Cuora amboinensis in Malaysia most closely resembles N. spinometraterminis from Kachuga tectum tentoria in India by possessing postovarian cecal tips and an average of more than 30 vitelline follicles, but differs by having equatorial rather than preequatorial testes which are mostly intercecal rather than extracecal and a slightly smaller cirrus sac, Neopronocephaius spinometraterminis purportedly has spines in the metraterm and a common genital pore, whereas N . orientalis exhibits nonstaining wrinkled epithelium lining the metraterm and separate genital pores. Spirhapalum elongatum was also collected from its type host near the type locality

Description of \u3ci\u3eBuckarootrema goodmani\u3c/i\u3e n. g., n. sp. (Digenea: Pronocephalidae), a Parasite of the Freshwater Turtle \u3ci\u3eEmydura macquarii\u3c/i\u3e (Gray, 1830) (Pleurodira: Chelidae) from Queensland, Australia, and a Phylogenetic Analysis of the Genera of the Pronocephalidae Looss, 1902

Buckarootrema goodmani n. g., n. sp. is described from the small intestine of the Murray turtle, Emydura macquarii (Gray, 1830), from the vicinity of Warwick, Queensland, Australia. The distinctive taxonomic features include the vitellarium, which consists of two compact masses directly anterior to and occasionally overlapping the testes; the uterus with extensive pre- and postovarian coils; intestinal ceca with small, medial diverticula that terminate anterior to or at the anterior margin of the testes; a comma-shaped cirrus sac with both internal and external seminal vesicles. Phylogenetic systematic analysis of the genera of the Pronocephalidae including Buckarootrema and Notopronocephalus, the only other genus of pronocephalids reported from Australian freshwater turtles, indicates that Buckarootrema is the sister taxon of Neopronocephalus and Notopronocephalus is the sister group of the rest of the Pronocephalinae

Description of \u3ci\u3eBuckarootrema goodmani\u3c/i\u3e n. g., n. sp. (Digenea: Pronocephalidae), a Parasite of the Freshwater Turtle \u3ci\u3eEmydura macquarii\u3c/i\u3e (Gray, 1830) (Pleurodira: Chelidae) from Queensland, Australia, and a Phylogenetic Analysis of the Genera of the Pronocephalidae Looss, 1902

Buckarootrema goodmani n. g., n. sp. is described from the small intestine of the Murray turtle, Emydura macquarii (Gray, 1830), from the vicinity of Warwick, Queensland, Australia. The distinctive taxonomic features include the vitellarium, which consists of two compact masses directly anterior to and occasionally overlapping the testes; the uterus with extensive pre- and postovarian coils; intestinal ceca with small, medial diverticula that terminate anterior to or at the anterior margin of the testes; a comma-shaped cirrus sac with both internal and external seminal vesicles. Phylogenetic systematic analysis of the genera of the Pronocephalidae including Buckarootrema and Notopronocephalus, the only other genus of pronocephalids reported from Australian freshwater turtles, indicates that Buckarootrema is the sister taxon of Neopronocephalus and Notopronocephalus is the sister group of the rest of the Pronocephalinae

\u3ci\u3eNeopronocephalus orientalis\u3c/i\u3e Sp. n. (Digenea: Pronocephalidae) and \u3ci\u3eSpirhapalum elongatum\u3c/i\u3e Rohde, Lee, and Lim, 1968 (Digenea: Spirorchiidae) from \u3ci\u3eCuora amboinensis\u3c/i\u3e (Daudin) in Malaysia

Neopronocephalus orientalis from Cuora amboinensis in Malaysia most closely resembles N. spinometraterminis from Kachuga tectum tentoria in India by possessing postovarian cecal tips and an average of more than 30 vitelline follicles, but differs by having equatorial rather than preequatorial testes which are mostly intercecal rather than extracecal and a slightly smaller cirrus sac, Neopronocephaius spinometraterminis purportedly has spines in the metraterm and a common genital pore, whereas N . orientalis exhibits nonstaining wrinkled epithelium lining the metraterm and separate genital pores. Spirhapalum elongatum was also collected from its type host near the type locality

\u3ci\u3eTorquatoides trogoni\u3c/i\u3e n. sp. and \u3ci\u3eExcisa ramphastina\u3c/i\u3e n. sp. (Nematoda: Habronematoidea: Habronematidae) in Birds from the Área de Conservación Guanacaste, Costa Rica

Two new species of habronematid nematodes are described in birds from the Area de Conservacion Guanacaste, Costa Rica. Torquatoides trogoni n. sp., in Trogon massena, can be distinguished from T. torquata, T. bengalensis, and T. crotophaga in lacking lateral alae. Among species lacking lateral alae, the new species differs from T. balanocephala in having 14 versus 8-10 cephalic cuticular plaques, 21-22 versus 13-17 pairs of preanal papillae, and a beak-shaped versus U-shaped gubernaculum. The new species differs from T. singhi in body length, in having 21-22 versus 10 pairs of precloacal papillae, longer spicules, and larger eggs. The new species differs from T. crotophaga, the only other species known from Central America, in lacking lateral alae, and having 14 versus 6 cephalic cuticular plaques, 21-22 versus 17 pairs of precloacal and 3 versus 2 pairs of postcloacal papillae, and a gubernaculum. Excisa ramphastina n. sp., in Ramphastos sulfuratus, can be distinguished from E. excisa, E. biloba, E. buckleyi, E. dentifera, and E. khalili in having 1 lateral ala versus none, cervical papillae anterior versus posterior to the nerve ring, and asymmetrical caudal alae. Excisa ramphastina is similar to E. curvata in having cervical papillae anterior to the nerve ring but differs in having 1 lateral ala versus none, asymmetrical caudal alae, an average spicule ratio of 1:4.4 versus 1:3.3, and 4 versus 2 pairs of sessile papillae. The new species differs from E. columbi in having 1 versus 2 lateral alae, in the length of the spicules, in having a different spicule ratio, and in the numbers of sessile papillae