Protozoa Guide review

Trepomonas Dujardin

genus / DIPLOMONADIDA / HEXAMITIDAE

Description

Trepomonas are ovoid , bilaterally compressed cells (5-30 i-Jm) with 2 lateral locomotory flagella , 2 anterior nuclei, and 2 posterior grooves largely opened on each opposed side of the cell (Fig. 5) . The anterior part of the cell contains the 2 crescent-shaped nuclei , which abut on top and possess anterior nucleoli . Each set of 4 flagella are inserted on each side of the cell body near the equator at the base of each nucleus. The posterior half of the cell is grooved by 2 widely open cytostomal depressions or pockets , each containing 3 recurrent flagella, 1 of them being longer than others . The 2 locomotory flagella beat on each side and propel the cell , which generally moves by step-wise rotation . The bottom of the cytostomal pockets are the sites of the ingestion of food , mostly bacteria. One contractile vacuole forms in the middle part and discharges at the posterior end. Electron microscopic studies have shown the diplomonad characters : arrangement of the basal bodies and of the associated microtubular fibers. A transverse section (Fig . 3b) shows the cytostomal pockets opened on the flattened opposite faces of the cell , demonstrating the axial binary symmetry . Two cytostomal microtubular ribbons , 2 striated fibers , and a striated lamina border the faces of the cytostomal pockets . Cysts have been described . The 6 species described are free-living , but T. agilis which is a mesosaprobic species also occurs in intestine of amphibians , a marine fish, and tortoises . Light microscopic studies have been published by Klebs ( 1 8 9 2) , Lemmerman (191 0) , Grasse (1952) , Skuja (1956) , Calaway and Lackey (1962) , Mylnikov (1991 ); e lectron microscopy in Brugerolle et al . (1973) ; Eyden and Vickerman (1975) . Brugerolle et al. , 1973), with two anterior nuclei , two lateral locomotory flagella , two cytostoma l pockets opened on opposite sides and containing three recurrent flagella. Bar=1 0 1-1m. A

Type species

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Raw text

Trepomonas are ovoid , bilaterally compressed
cells (5-30 i-Jm) with 2 lateral locomotory
flagella , 2 anterior nuclei, and 2 posterior
grooves largely opened on each opposed side of the
cell (Fig. 5) . The anterior part of the cell
contains the 2 crescent-shaped nuclei , which
abut on top and possess anterior nucleoli . Each
set of 4 flagella are inserted on each side of the
cell body near the equator at the base of each
nucleus. The posterior half of the cell is grooved
by 2 widely open cytostomal depressions or
pockets , each containing 3 recurrent flagella, 1
of them being longer than others . The 2
locomotory flagella beat on each side and propel
the cell , which generally moves by step-wise
rotation . The bottom of the cytostomal pockets
are the sites of the ingestion of food , mostly
bacteria. One contractile vacuole forms in the
middle part and discharges at the posterior end.
Electron microscopic studies have shown the
diplomonad characters : arrangement of the basal
bodies and of the associated microtubular fibers.
A transverse section (Fig . 3b) shows the
cytostomal pockets opened on the flattened
opposite faces of the cell , demonstrating the axial
binary symmetry . Two cytostomal microtubular
ribbons , 2 striated fibers , and a striated lamina
border the faces of the cytostomal pockets . Cysts
have been described . The 6 species described are
free-living , but T. agilis which is a mesosaprobic
species also occurs in intestine of amphibians , a
marine fish, and tortoises . Light microscopic
studies have been published by Klebs ( 1 8 9 2) ,
Lemmerman (191 0) , Grasse (1952) , Skuja
(1956) , Calaway and Lackey (1962) , Mylnikov
(1991 ); e lectron microscopy in Brugerolle et al .
(1973) ; Eyden and Vickerman (1975) .
Brugerolle et al. , 1973), with two anterior nuclei ,
two lateral locomotory flagella , two cytostoma l
pockets opened on opposite sides and containing three
recurrent flagella. Bar=1 0 1-1m.
A