Skip to main content Accessibility help

A new microsporidian parasite, Potaspora morhaphis n. gen., n. sp. (Microsporidia) infecting the Teleostean fish, Potamorhaphis guianensis from the River Amazon. Morphological, ultrastructural and molecular characterization

  • G. CASAL (a1) (a2) (a3), E. MATOS (a4), M. L. TELES-GRILO (a5) and C. AZEVEDO (a1) (a3)


A fish-infecting Microsporidia Potaspora morhaphis n. gen., n. sp. found adherent to the wall of the coelomic cavity of the freshwater fish, Potamorhaphis guianensis, from lower Amazon River is described, based on light microscope and ultrastructural characteristics. This microsporidian forms whitish xenomas distinguished by the numerous filiform and anastomosed microvilli. The xenoma was completely filled by several developmental stages. In all of these stages, the nuclei are monokaryotic and develop in direct contact with host cell cytoplasm. The merogonial plasmodium divides by binary fission and the disporoblastic pyriform spores of sporont origin measure 2·8±0·3×1·5±0·2 μm. In mature spores the polar filament was arranged into 9–10 coils in 2 layers. The polaroplast had 2 distinct regions around the manubrium and an electron-dense globule was observed. The small subunit, intergenic space and partial large subunit rRNA gene were sequenced and maximum parsimony analysis placed the microsporidian described here in the clade that includes the genera Kabatana, Microgemma, Spraguea and Tetramicra. The ultrastructural morphology of the xenoma, and the developmental stages including the spores of this microsporidian parasite, as well as the phylogenetic analysis, suggest the erection of a new genus and species.


Corresponding author

*Corresponding author: Department of Cell Biology, Institute of Biomedical Sciences, University of Porto, Lg. A. Salazar no. 2, P-4099-003 Porto, Portugal. Tel: +351 22 206 22 00. Fax: +351 22 206 22 32/33. E-mail:,


Hide All
Azevedo, C. and Matos, E. (2002). Fine structure of a new species, Loma myrophis (Phylum Microsporidia), parasite of the Amazonian fish Myrophis platyrhynchus (Teleostei, Ophichthidae). European Journal of Protistology 37, 445452.
Azevedo, C. and Matos, E. (2003). Amazonspora hassar n. gen. and n. sp. (phylum Microsporidia, fam Glugeidae), a parasite of the Amazonian teleost Hassar orestis (fam. Doradidae). Journal of Parasitology 89, 336341.
Azevedo, C., Balseiro, P., Casal, G., Gestal, C., Aranguren, R., Stokes, N. A., Carnegie, R. B., Novoa, N., Burreson, E. M. and Figueras, A. (2006). Ultrastructural and molecular characterization of Haplosporidium montforti n. sp., parasite of the European abalone Haliotis tuberculata. Journal of Invertebrate Pathology 92, 2332.
Baquero, E., Rubio, M., Moura, I. N. S., Pieniazek, J. and Jordana, R. (2005). Myosporidium merluccius n. g., n. sp. infecting muscle of commercial hake (Merluccius sp.) from fisheries near Namibia. The Journal of Eukaryotic Microbiology 52, 476483.
Bell, A. S., Aoki, T. and Yokoyama, H. (2001). Phylogenetic relationships among Microsporidia based on rDNA sequence data, with particular reference to fish-infecting Microsporidium Balbiani 1884 species. The Journal of Eukaryotic Microbiology 48, 258265.
Casal, G. and Azevedo, C. (1995). New ultrastructural data on the microsporidian Ichthyosporidium giganteum infecting the marine teleostean fish Ctenolabrus rupestris. Journal of Fish Diseases 18, 191194.
Cheney, S. A., Lafranchi-Tristem, N. J. and Canning, E. U. (2000). Phylogenetic relationships of Pleistophora-like Microsporidia based on small subunit ribosomal DNA sequences and implications for the source of Trachipleistophora hominis infections. The Journal of Eukaryotic Microbiology 47, 280287.
Faye, N., Toguebaye, B. S. and Bouix, G. (1991). Microfilum lutjani n. g. n. sp. (Protozoa, Microsporida), a gill parasite of the golden African snapper Lutjanus fulgens (Valenciennes, 1830) (Teleost Lutjanidae): Developmental cycle and ultrastructure. Journal of Protozoology 38, 3040.
Freeman, M. A., Yokoyama, H. and Ogawa, K. (2004). A microsporidian parasite of the genus Spraguea in the nervous tissues of the Japanese anglerfish Lophius litulon. Folia Parasitologica 51, 167176.
Gatehouse, H. S. and Malone, L. A. (1998). The ribosomal RNA gene region of Nosema apis (Microspora): DNA sequence for small and large subunit rRNAgenes and evidence of a large tandem repeat unit size. Journal of Invertebate Pathology 71, 97105.
Larsson, J. I. R. (1999). Identification of Microsporidia. Acta Protozoologica 38, 161197.
Leiro, J., Siso, M. I. G., Parama, A., Ubeira, F. M. and Sanmartin, M. L. (2000). RFLP analysis of PCR-amplified small subunit ribosomal DNA of three fish microsporidian species. Parasitology 120, 113119.
Lom, J. (2002). A catalogue of described genera and species of microsporidians parasitic in fish. Systematic Parasitology 53, 8199.
Lom, J. and Dyková, I. (1992). Microsporidia (Phylum Microspora Sprague, 1977). In Protozoan Parasites of Fishes. Developments in Aquaculture and Fisheries Sciences (ed. Lom, J. and Dyková, I.), Vol. 26, pp. 125157. Elsevier, Amsterdam.
Lom, J., Dyková, I. and Tonguthai, K. (1999). Kabataia gen. n., new genus proposed for Microsporidium spp. infecting trunk muscles of fishes. Diseases of Aquatic Organisms 38, 3946.
Lom, J. and Nilsen, F. (2003). Fish Microsporidia: fine structural diversity and phylogeny. International Journal for Parasitology 33, 107127.
Lom, J., Nilsen, F. and Urawa, S. (2001). Redescription of Microsporidium takedai (Awakura, 1974) as Kabatana takedai (Awakura, 1974) comb. n. Diseases of Aquatic Organisms 44, 223230.
Lom, J. and Pekkarinen, M. (1999). Ultrastructural observations on Loma acerinae (Jírovec, 1930) comb. nov. (Phylum Microsporidia). Acta Protozoologica 38, 6174.
Mansour, L., Prensier, G., Jemaa, S. B., Hassine, O. K. B., Méténier, G., Vivarès, C. P. and Cornillot, E. (2005). Description of a xenoma-inducing microsporidian, Microgemma tincae n. sp., a parasite of the teleost fish Symphodus tinca from Tunisian coasts. Diseases of Aquatic Organisms 65, 217226.
Matos, E. and Azevedo, C. (2004). Ultrastructural description of Microsporidium brevirostris sp. n., parasite of the teleostean Brachyhypopomus brevirostris (Hypopomidae) from the Amazon River. Acta Protozoologica 43, 261267.
Matos, E., Corral, L. and Azevedo, C. (2003). Ultrastructural details of the xenoma of Loma myrophis (phylum Microsporidia) and extrusion of the polar tube during autoinfection. Diseases of Aquatic Organisms 54, 203207.
Matthews, R. A. and Matthews, B. F. (1980). Cell and tissue reactions of turbot Scophthalmus maximus (L.) to Tetramicra brevifilum gen. n., sp. n. (Microspora). Journal of Fish Diseases 3, 495515.
Nilsen, F. (2000). Small subunit ribosomal DNA phylogeny of Microsporidia with particular reference to genera that infect fish. Journal of Parasitology 86, 128133.
McGourty, K. R., Kinzger, A. P., Hendrickson, G. L., Goldsmith, G. L., Casal, G. and Azevedo, C. (2007). A new microsporidian infecting the musculature of the endangered tidewater goby (Gobiidae). Journal of Parasitology 93, 655660.
Sprague, V., Becnel, J. J. and Hazard, E. I. (1992). Taxonomy of phylum Microspora. Critical Reviews in Microbiology 18, 285395.
Sprague, V. and Vernick, S. (1974). Fine structure of the cyst and some sporulation stages of Ichthyosporidium (Microsporidia). Journal of Protozoology 21, 667677.
Tamura, K., Dudley, J., Nei, M. and Kumar, S. (2007). MEGA4: Molecular evolutionary genetics analysis (MEGA) software version 4.0. Molecular Biology and Evolution 24, 15961599.
Thompson, J. D., Higgins, D. G. and Gilson, T. J. (1994). Clustal W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic Acids Research 22, 46734680.
Vossbrinck, C. R., Baker, M. D., Didier, E. S., Debrunner-Vossbrinck, B. A. and Shadduck, J. A. (1993). Ribosomal DNA sequences of Encephalitozoon hellem and Encephalitozoon cuniculi: species identification and phylogenetic construction. The Journal Eukaryotic of Microbiology 40, 354362.
Weiss, L. and Vossbrinck, C. (1999). Molecular biology, molecular phylogeny, and molecular diagnostic approaches to the Microsporidia. In The Microsporidia and Microsporidiosis (ed. Wittner, M. and Weiss, L.), pp. 129171. American Society of Microbiology, Washington, DC.


A new microsporidian parasite, Potaspora morhaphis n. gen., n. sp. (Microsporidia) infecting the Teleostean fish, Potamorhaphis guianensis from the River Amazon. Morphological, ultrastructural and molecular characterization

  • G. CASAL (a1) (a2) (a3), E. MATOS (a4), M. L. TELES-GRILO (a5) and C. AZEVEDO (a1) (a3)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed