Protozoa Guide review

Octomitus Prowazek

genus / DIPLOMONADIDA / HEXAMITIDAE

Description

Octomitus (syn=Syndyomita) has a cell body broadly pyriform, tapered posteriorly bearing 6 anterior flagella and 2 posterior trailing ones (Fig . 10) . The 2 anterior nuclei are bean- shaped; they face up and adjoin each other in their anterior part . A large endosome is present in the posterior lobe of the nuclei . Two sets of 3 flagella emerge on each side of the anterior part of the body. The 2 recurrent flagella traverse the cell forming a central axis before emerging as trailing flagella . The study of their ultrastructure has shown that the basal bodies are located between the 2 nuclei. In each karyomastigont, 2 anterior flagella emerge on one side and the third anterior flagellum on the opposite side of the cell . The supra-nuclear fibers are reduced . The 2 axonemes of the A recurrent flagella are accompanied by microtubular fibers and by stacks of rough endop lasmic reticulum (Fig . 3g) . Posteriorly the fibers spread around the flagella emergence , and there are 2 additional dense fibers which form 2 terminal spikes. There are no cytostomal openings or cytopharyngeal canals; these structures are cryptic . Endocytosis takes place in any part of the cell surface . The 2 species identified are parasitic in the intestine and transmitted by cysts. A general description and a list of species and synonyms is provided by Kulda and Nohynkova (1978). Octomitus neglecta from amphib ians and 0. intestinalis from rodents have been studied by electron microscopy (Brugerolle et al., 1974b) . mice (from Brugerolle et al., 1974b). The axonemes of the two trailing flagella are axial. Bar=1 0 ~m .

Type species

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Raw text

Octomitus (syn=Syndyomita) has a cell body
broadly pyriform, tapered posteriorly bearing 6
anterior flagella and 2 posterior trailing ones
(Fig . 10) . The 2 anterior nuclei are bean-
shaped; they face up and adjoin each other in their
anterior part . A large endosome is present in the
posterior lobe of the nuclei . Two sets of 3 flagella
emerge on each side of the anterior part of the
body. The 2 recurrent flagella traverse the cell
forming a central axis before emerging as
trailing flagella . The study of their
ultrastructure has shown that the basal bodies
are located between the 2 nuclei. In each
karyomastigont, 2 anterior flagella emerge on one
side and the third anterior flagellum on the
opposite side of the cell . The supra-nuclear
fibers are reduced . The 2 axonemes of the
A
recurrent flagella are accompanied by
microtubular fibers and by stacks of rough
endop lasmic reticulum (Fig . 3g) . Posteriorly the
fibers spread around the flagella emergence , and
there are 2 additional dense fibers which form 2
terminal spikes. There are no cytostomal
openings or cytopharyngeal canals; these
structures are cryptic . Endocytosis takes place
in any part of the cell surface . The 2 species
identified are parasitic in the intestine and
transmitted by cysts. A general description and a
list of species and synonyms is provided by Kulda
and Nohynkova (1978). Octomitus neglecta from
amphib ians and 0. intestinalis from rodents have
been studied by electron microscopy (Brugerolle
et al., 1974b) .
mice (from Brugerolle et al., 1974b). The axonemes
of the two trailing flagella are axial. Bar=1 0 ~m .