Folia Parasitologica 50[1] 37-42 (2003) | DOI: 10.14411/fp.2003.006

Fine structure of Henneguya pilosa sp. n. (Myxozoa: Myxosporea), parasite of Serrasalmus altuvei (Characidae), in Brazil

Carlos Azevedo¹, Edílson Matos²

¹ Department of Cell Biology, Institute of Biomedical Sciences, and CIIMAR, University of Oporto, Lg. Abel Salazar No. 2, 4099-003 Porto, Portugal

² Laboratory of Animal Biology, Faculty of Agricultural Sciences of Pará, 66.000 Belém - PA, Brazil

Henneguya pilosa sp. n., a new species of myxosporean from the gill filaments of the white piranha, Serrasalmus altuvei Ramirez, 1965 (Characidae), a freshwater teleost fish collected in the Zoological Garden of the city of Teresina (Piauí), Brazil, is described from light and transmission electron microscope observations. This myxosporean produced small plasmodia (up to 0.2 mm in diameter), each one containing all life-cycle stages of the parasite, including numerous spores. The spores, laterally compressed, averaged 54.2 (52.3-56.0) µm in total length and consisted of two unequal valves adhering together along the suture line and two caudal processes. The spore body measured 21.1 (20.0-23.1) µm in length, 5.9 (5.5-6.3) µm in width, and 2.2 (1.9-2.6) µm in thickness. The two equal ellipsoidal polar capsules of 7.4 (7.1-7.6) µm long and 1.2 (1.0-1.3) µm wide possessed a polar filament with 11-12 (rarely 13) turns. All surfaces of the spores were covered with a tightly adherent complex network of numerous densely ramified granulo-fibrillar masses, the longest measuring 1.5 µm long, observed around the caudal processes. The prevalence of infection was 30%. The taxonomic affinities of this parasite with other of the same genus in freshwater South American fish species are discussed.

Keywords: Myxozoa, Henneguya pilosa, ultrastructure, parasite, fish

Received: April 30, 2002; Accepted: September 10, 2002; Published: March 1, 2003  Show citation