Protozoa Guide review

Spironucleus Lavier

genus / DIPLOMONADIDA / HEXAMITIDAE

Description

Ovoid or cigar-shaped cell body (5-1 0 1-1m) tapered posteriorly bearing 6 anterior flagella 11 32 DIPLOMONADID and 2 posterior trailing ones (Figs. 8b , 9) . Spironucleus was distinguished from Hexamita and Octomitus on the basis that its nuclei were S shape or slightly spiralled and more elongated than Hexamita (Lavier , 1936). Electron microscopy has confirmed the shape of the nuclei which present an anterior knob. The basal bodies of the flagella are inserted at the base of these knobs which are surrounded by the supra- nuclear fibers (Fig. 3e). The 2 recurrent flagella in their canal run between the 2 nuclei (Fig . 3f) in contrast to Hexamita where they are located on the external face of the nuclei. There are 2 to 3 microtubular fibers around the canals and a dense lamina but not much rough endoplasmic reticulum . Complex structures around the posterior cytostomal openings have been observed. These organisms are intestinal parasites ; they feed on digested food. They form ovoid cysts with a thick cyst wall . At least 3 species identified. They live in the intestine of various vertebrates such as S. e/egans from amphibians (Grasse, 1952) and fishes (Becker , 1977). Some are pathogenic such asS. muris for mice and S. me/eagridis for turkeys. A list of species is given in Kulda and Nohynkova ( 1 9 7 8) . Several species have been studied by electron microscopy: S. elegans from amphibians (Brugerolle et al. , 1974a) , S. intestinalis from mice (Brugerolle et al. , 1980) , S. torosa from fishes (Poynton and Morrison, 1990; Poynton et al. , 1995; Sterud , 1998; Sterud et al. , 1997). SUBFAMILY GIARDIINAE Genera of this subfamily have no cytostome.

Type species

Figures

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Raw text

Ovoid or cigar-shaped cell body (5-1 0 1-1m)
tapered posteriorly bearing 6 anterior flagella
11 32 DIPLOMONADID
and 2 posterior trailing ones (Figs. 8b , 9) .
Spironucleus was distinguished from Hexamita
and Octomitus on the basis that its nuclei were S
shape or slightly spiralled and more elongated
than Hexamita (Lavier , 1936). Electron
microscopy has confirmed the shape of the nuclei
which present an anterior knob. The basal bodies
of the flagella are inserted at the base of these
knobs which are surrounded by the supra-
nuclear fibers (Fig. 3e). The 2 recurrent
flagella in their canal run between the 2 nuclei
(Fig . 3f) in contrast to Hexamita where they are
located on the external face of the nuclei. There
are 2 to 3 microtubular fibers around the canals
and a dense lamina but not much rough
endoplasmic reticulum . Complex structures
around the posterior cytostomal openings have
been observed. These organisms are intestinal
parasites ; they feed on digested food. They form
ovoid cysts with a thick cyst wall . At least 3
species identified. They live in the intestine of
various vertebrates such as S. e/egans from
amphibians (Grasse, 1952) and fishes (Becker ,
1977). Some are pathogenic such asS. muris for
mice and S. me/eagridis for turkeys. A list of
species is given in Kulda and Nohynkova ( 1 9 7 8) .
Several species have been studied by electron
microscopy: S. elegans from amphibians
(Brugerolle et al. , 1974a) , S. intestinalis from
mice (Brugerolle et al. , 1980) , S. torosa from
fishes (Poynton and Morrison, 1990; Poynton et
al. , 1995; Sterud , 1998; Sterud et al. , 1997).
SUBFAMILY GIARDIINAE
Genera of this subfamily have no cytostome.