Folia Parasitologica 50[3] 161-170 (2003) | DOI: 10.14411/fp.2003.030

Nuclearia pattersoni sp. n. (Filosea), a new species of amphizoic amoeba isolated from gills of roach (Rutilus rutilus), and its rickettsial endosymbiont

Iva Dyková^1,2, Marie Veverková^1,2, Ivan Fiala^1,2, Blanka Macháčková¹, Hana Pecková¹

¹ Institute of Parasitology, Academy of Sciences of the Czech Republic, Branišovská 31, 370 05 České Budějovice, Czech Republic

² Faculty of Biological Sciences, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic

A new species of amphizoic amoeba, Nuclearia pattersoni sp. n., isolated from gills of Rutilus rutilus L. is described. It is characterised by elongate flattened trophozoites of irregular shape. The longer dimension of their bodies is 13.2 (11.0-15.7) µm. Filopodia radiating mostly from the poles are 2 to 2.5 times longer than the body. The diameter of less frequently observed spherical trophozoites is 8.2-10.8 µm; their filopodia radiate to all directions. Cyst-like stages have shorter pseudopodia that arise from one pole only. The surface of locomotive forms from agar plate cultures has a thin amorphous glycocalyx, while most cells are covered by two layers of extracellular matrix. Mitochondria have flattened cristae, dictyosomes are located in the perinuclear zone. A conspicuous ultrastructural feature of the morphologically similar N. simplex, perinuclear striated band, is not present. Light microscopic and ultrastructural data are completed with the sequence of SSU rRNA gene and phylogenetic analysis including sequences of related taxa. The bacterial endosymbiont found in N. pattersoni type strain RR2G2 is assigned to the genus Rickettsia.

Keywords: Filosea, Nuclearia pattersoni, SSU rDNA, Vampyrellidium perforans, rickettsial endosymbiont

Received: April 4, 2003; Accepted: June 18, 2003; Published: September 1, 2003  Show citation