Protozoa Guide review

RETORTAMONADIDA, GRASSE

order / RETORTAMONADIDA, GRASSE

Description

by GUY BRUGEROLLE and JOHN J. LEE Retortamonads are small (5-20 ~m) bacterivor- ous flagellates with two or four flagella ; one of them is turned backward and associated with a conspicuous antero-ventral cytostomal aperture (Fig. ~a). B~sal bodies of the flagella are closely assoc1ated w1th the anterior nucleus and with the two fibrils lining the cytostome. The right lip of the cytostome is bordered by a striated or paracrystalline fiber which terminates by a posterior hook (Fig . 1 d,e) . The cell surface is underlain by a corset of microtubules (Fig. 1 c) except in the bottom of the cytostome where endocytosis takes place. The recurrent flagellum has typically two to three fin-like lamellae along the axoneme (Fig . 1d ,e) . There are no mitochondria , Golgi apparatus , hydrogenosomes , or axostyles. They reproduce by binary fission and the mi_totic spindle is intranuclear . They are transmitted from host to host by resistant cysts . Most of them are parasitic in the digestive tract of animals; however , free -living species have been reported (Bernard et al. , 1997) . The group has been described in Brugerolle (1991 ); Brugerolle and Mignot (1990) ; Vickerman (1982). Only two genera have been described: Retortamonas and Chilomastix.

Type species

Figures

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Raw text

by
GUY BRUGEROLLE and JOHN J. LEE
Retortamonads are small (5-20 ~m) bacterivor-
ous flagellates with two or four flagella ; one of
them is turned backward and associated with a
conspicuous antero-ventral cytostomal aperture
(Fig. ~a). B~sal bodies of the flagella are closely
assoc1ated w1th the anterior nucleus and with the
two fibrils lining the cytostome. The right lip of
the cytostome is bordered by a striated or
paracrystalline fiber which terminates by a
posterior hook (Fig . 1 d,e) . The cell surface is
underlain by a corset of microtubules (Fig. 1 c)
except in the bottom of the cytostome where
endocytosis takes place. The recurrent flagellum
has typically two to three fin-like lamellae along
the axoneme (Fig . 1d ,e) . There are no
mitochondria , Golgi apparatus , hydrogenosomes , or
axostyles. They reproduce by binary fission and
the mi_totic spindle is intranuclear . They are
transmitted from host to host by resistant cysts .
Most of them are parasitic in the digestive tract of
animals; however , free -living species have been
reported (Bernard et al. , 1997) . The group has
been described in Brugerolle (1991 ); Brugerolle
and Mignot (1990) ; Vickerman (1982). Only two
genera have been described: Retortamonas and
Chilomastix.