24 research outputs found
Strong association between parasitism and phenotypic variation in a supralittoral amphipod
Morphological and molecular characterization of two new species of Andracantha (Acanthocephala: Polymorphidae) from New Zealand shags (Phalacrocoracidae) and penguins (Spheniscidae) with a key to the species
Copyright © Cambridge University Press 2017 Two new species of Andracantha (Polymorphidae) are described from the intestine of the shags Leucocarbo chalconotus (Gray) and Phalacrocorax punctatus (Sparrman), and the penguin Eudyptula minor (Forster) from southern South Island, New Zealand. Andracantha leucocarboi n. sp. is distinguished from its congeners by having no genital or ventral trunk spines, but possessing a scattering of small spines between the anterior fields of spines. This is the first record of a species of Andracantha from a penguin. Circumbursal papillae are illustrated in a scanning electron micrograph for the first time in the polymorphids. Andracantha sigma n. sp. is distinguished by the sigmoid shape of its largest proboscis hook, hook VIII, and having the ventral field separated from the posterior disc field by an aspinous gap. A Maximum Likelihood tree from cox1 and large ribosomal subunit (LSU) data shows A. leucocarboi n. sp. to be more closely related to A. gravida than A. sigma n. sp. and the genus Andracantha as sister to Corynosoma spp. Genetic distances between species of Andracantha are comparatively large. A key to the species of Andracantha is provided
Morphological and molecular characterisation of a new genus and species of acanthocephalan, Tenuisoma tarapungi n. g., n. sp. (Acanthocephala: Polymorphidae) infecting red-billed gulls in New Zealand, with a key to the genera of the Polymorphidae Meyer, 1931
Acanthocephalans of the family Polymorphidae Meyer, 1931 are cosmopolitan parasites that infect the intestines of fish-eating birds and mammals. Polymorphid acanthocephalans recovered from the intestines of red-billed gulls (Chroicocephalus scopulinus (Forster)) from the Otago coast, New Zealand, although morphologically similar to the genus Arhythmorhynchus Lühe, 1911 nevertheless have a unique molecular profile showing considerable genetic differentation, and are here diagnosed and described as Tenuisoma tarapungi n. g., n. sp. Characters which distinguish T. tarapungi include a very elongate, cylindrical hindtrunk, swollen anterior trunk with a spinose region, a secondary swelling in males only containing the testes, and hypodermal nuclei distributed throughout the length of the trunk. Molecular data (cox1, 18S, 28S) confirm that the representative of the new genus is closest to, but nonetheless strongly divergent from species of Pseudocorynosoma Aznar, Pérez-Ponce de León & Raga, 2006. Immature specimens are described and illustrated, demonstrating the extreme degree of hindtrunk inversion occurring in immature individuals of this species. We provide a key to the genera of the family Polymorphidae. © 2020, Springer Nature B.V
Morphological and molecular characterization of two new species of Andracantha (Acanthocephala: Polymorphidae) from New Zealand shags (Phalacrocoracidae) and penguins (Spheniscidae) with a key to the species
Copyright © Cambridge University Press 2017 Two new species of Andracantha (Polymorphidae) are described from the intestine of the shags Leucocarbo chalconotus (Gray) and Phalacrocorax punctatus (Sparrman), and the penguin Eudyptula minor (Forster) from southern South Island, New Zealand. Andracantha leucocarboi n. sp. is distinguished from its congeners by having no genital or ventral trunk spines, but possessing a scattering of small spines between the anterior fields of spines. This is the first record of a species of Andracantha from a penguin. Circumbursal papillae are illustrated in a scanning electron micrograph for the first time in the polymorphids. Andracantha sigma n. sp. is distinguished by the sigmoid shape of its largest proboscis hook, hook VIII, and having the ventral field separated from the posterior disc field by an aspinous gap. A Maximum Likelihood tree from cox1 and large ribosomal subunit (LSU) data shows A. leucocarboi n. sp. to be more closely related to A. gravida than A. sigma n. sp. and the genus Andracantha as sister to Corynosoma spp. Genetic distances between species of Andracantha are comparatively large. A key to the species of Andracantha is provided
Novel morphological and molecular data for Corynosoma hannae Zdzitowiecki, 1984 (Acanthocephala: Polymorphidae) from teleosts, fish-eating birds and pinnipeds from New Zealand
The polymorphid acanthocephalan, Corynosoma hannae Zdzitowiecki, 1984 is characterised on the basis of newly collected material from a New Zealand sea lion, Phocarctos hookeri (Gray), and long-nosed fur seal, Arctophoca forsteri (Lesson) (definitive hosts), and from Stewart Island shags, Leucocarbo chalconotus (Gray), spotted shags, Phalacrocorax punctatus (Sparrman) and yellow-eyed penguins, Megadyptes antipodes (Hombron & Jacquinot) (non-definitive hosts) from New Zealand. Specimens are described in detail and scanning electron micrographs for C. hannae are provided. Additionally, cystacanths of C. hannae are reported and described for the first time from the body cavity and mesenteries of New Zealand brill, Colistium guntheri (Hutton) and from New Zealand sole, Peltorhamphus novaezeelandiae GĂĽnther from Kaka Point, Otago in New Zealand. Partial sequence data for the mitochondrial cytochrome c oxidase 1 gene (cox1) for adults, immature specimens and cystacanths of C. hannae were obtained. Phylogenetic analyses of the newly-generated sequences and for available cox1 sequences of Corynosoma spp. revealed a close relationship between C. hannae and C. australe Johnston, 1937, both species infecting pinnipeds in the Southern Hemisphere. However, a morphological comparison of the species suggests that C. hannae mostly closely resembles C. evae Zdzitowiecki, 1984 and C. semerme (Forssell, 1904), the latter of which occurs in pinnipeds in the Northern Hemisphere
Fish biogeography in the “Lost World” of the Guiana Shield: Phylogeography of the weakly electric knifefish Gymnotus carapo
AimThe Guiana Shield region exhibits extraordinary topography that includes sheer, flatâ topped mountains (tepuis) atop an upland platform. Rivers of the eastern Pakaraima Mountains descend to Atlantic coastal lowlands, often traversing spectacular rapids and waterfalls. For fish species distributed in both uplands and lowlands, it is unclear whether these rapids and waterfalls present population or biogeographical boundaries. We sought to test this using the geographically widespread bandedâ electric knifefish (Gymnotus carapo) as a model.LocationThe Guiana Shield region of South America.MethodsWe sampled 60 Gymnotus carapo specimens from the Guiana Shield region, and 75 G. carapo and closely related species from other parts of South America. We sequenced the mitochondrial cytochrome b gene and an intron from the nuclear S7 ribosomal protein gene, and used maximum likelihood and Bayesian treeâ building approaches to generate phylogenetic trees of haplotypes.ResultsHaplotype sharing is minimal between populations separated by elevational barriers. We found evidence for two main haplotype clades in the Guiana Shield: one distributed in Atlantic coastal regions that includes most lowland samples, and one inland that includes most upland samples. Inland Guiana samples are more closely related to samples from the Amazon basin than to those of Atlantic coastal regions. A single sample from Tafelberg tepui in Suriname was most closely related to the Atlantic coastal lineages.Main conclusionsRiverine barriers that result from steep elevational gradients in the Guiana Shield inhibit gene flow between uplands and lowlands, even for a widely distributed species. Biogeographical relationships of Guiana Shield G. carapo are complex, with most upland lineages showing affinities to the Amazon basin, rather than to nearby lowland drainages of the Atlantic coast.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142908/1/jbi13177.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142908/2/jbi13177_am.pd