A morphological and molecular study of two species of Raphidascaroides Yamaguti, 1941 (Nematoda: Anisakidae), parasites of doradid catfish (Siluriformes) in South America, with a description of R. moraveci n. sp.
Nematodes of the genus Raphidascaroides Yamaguti, 1941 parasitising doradid catfishes (Siluriformes: Doradidae) in Brazil were studied based on morphological and molecular evaluation of newly collected material. A new species, Raphidascaroides moraveci n. sp., is described from the intestine of Platydoras armatulus (Valenciennes) from River Miranda, River Paraguay basin, Pantanal, Mato Grosso do Sul. The new species differs from all of the congeners in having short spicules (163–217 μm in length) representing less than 1% of the total body length and in the posterior region of cloacal opening covered by small rudimentary spines. In addition, it differs from the other congeneric species in the number and arrangement of the caudal papillae and the structure of lips and tail. Raphidascaroides moraveci n. sp. is the third species described from freshwater fishes and the second one in the Neotropical Region. New morphological data on R. brasiliensis Moravec & Thatcher, 1997 from Megalodoras uranoscopus (Eigenmann & Eigenmann) and Platydoras costatus (Linnaeus) (both new host records) from River Xingu, River Amazon basin, Pará, are provided including scanning electron micrographs of taxonomically important structures. The differentiation of the new species is supported by molecular data (partial sequences of the small and large subunits of the rRNA gene).
KeywordsTotal Body Length Excretory Pore Anisakid Nematode River Amazon Basin Precloacal Papilla
This study was supported by the “Ciência sem fronteiras” Brazilian program for visiting researchers (No. 135/2012; stay of TS at the Universidade Federal Rural de Rio de Janeiro) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grants to JLL (Nos 474077/2011-0, 304254/2011-8, 402665/2012-0). FBP was supported by a CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) fellowship for a five month stay at the Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice (IPCAS). TS was also supported by the IPCAS (RVO: 60077344) and the Czech Science Foundation (P505/12/G112). The authors’ thanks are also due to the staff of the Laboratory of Electron Microscopy, IPCAS, for their technical assistance, Blanka Škoríková for help in providing scientific literature, František Moravec for his valuable comments during manuscript preparation and Jan Brabec, all from the IPCAS, for help with molecular analyses, and David Gonzalez-Solís from El Colegio de la Frontera Sur, Chetumal, Mexico, for valuable advice. Thanks are also due to Aldenice Pereira, Fabiano Paschoal, Philippe Vieira Alves and Juliana Moreira for help with fish collection and parasitological examination and Emil José Hernández Ruiz, Universidade Federal do Pará, Altamira, for providing the facilities during the field trip to the River Xingu. Finally, the authors would also like to thank Fernando Paiva and the staff of the Universidade Federal do Mato Grosso do Sul, for providing logistical support and facilities during collecting trip to the River Miranda.
- Anderson, R C., Chabaud, A. G., & Willmott, S. (2009). Keys to the nematode parasites of vertebrates: archival volume. Wallingford: CABI Publishing, 480 pp. Google Scholar
- Bilqees, F. M., Shaukat, N., Navqi, S. M. H. M., & Medi, R. (2005). Raphidascaroides elongatus sp. n. (Nematoda: Anisakidae) from the fish Pellona elongata Bennet of Korangi Creek, Karachi, Pakistan. International Journal of Biology and Biotechnology, 2, 811–813.Google Scholar
- Bruce, N. L. (1990). Hysterothylacium Ward and Magath, 1917, and Ichthyascaris Wu, 1949, ascaridoid nematodes from Australian demersal fishes. Memoirs of the Queensland Museum, 28, 389–426.Google Scholar
- Froese, R., & Pauly, D. (Eds) (2014). FishBase. World Wide Web electronic publication. http://www.fishbase.org, version 06/2014.
- Khalil, L. F., & Oyetayo, A. S. (1988). Raphidascaroides africanus sp. nov. (Nematoda: Anisakidae) from the fish Bostrychus africanus in Nigeria and a key to the species of the genus Raphidascaroides Yamaguti, 1941. Journal of African Zoology, 102, 85–91.Google Scholar
- Moravec, F. (1998). Nematodes of the freshwater fishes of the Neotropical region. Prague: Academia, 464 pp.Google Scholar
- Nunn, G. B. (1992). Nematode molecular evolution. PhD Dissertation. University of Nottingham, UK, 187 pp.Google Scholar
- Petter, A. J. (1995). Nematodes de poissons du Paraguay. VIII. Habronematoidea, Dracunculoidea et Ascaridoidea. Revue Suisse de Zoologie, 102, 89–102.Google Scholar
- Rajyalakshmi, I. (1994). Raphidascaroides indicus n. sp. (Nematoda: Heterocheilidae) from the stomach of shark Chiloscyllium indicum (Gmelin) of Visakhaptnam. Rivista di Parassitologia, 11, 179–185.Google Scholar
- Rajyalakshmi, I. (1995). Raphidascaroides bengali n. sp. Nematoda: Heterocheilidae from marine eel fish. Uroconger lepturus Richardson. Rivista di Parassitologia, 123, 467–473.Google Scholar
- Yamaguti, S. (1941). Studies on the helminth fauna of Japan. Part 33. Nematodes of fishes II. Japanese Journal of Zoology, 9, 343–396.Google Scholar
- Yamaguti, S. (1961). Studies on the helminth fauna of Japan. Part 57. Nematodes of fishes, III. Journal of Helminthology, R. T. Leiper Supplement, 217–228.Google Scholar