Odontochlamys
Odontochlamys Certes, 1891 (ref. ID; 2013, 3331, 4819)
Class Kinetofragminophora: Subclass Hypostomata: Order Cyrtophorida: Suborder Chlamydodontina (ref. ID; 2013)
Family Chilodonellidae (ref. ID; 3331)
[ref. ID; 2013]
Outline shape oval to pyriform, convex on left side, concave on right. Dorso-ventrally flattened, ventral surface flat, dorsal surface strongly arched. Genus easy to identify because of the bump-like spines (4 to 13) which project out from the dorsal surface around the periphery of the cell. Somatic ciliature restricted to ventral surface where there is a simplification as in Chilodonatella. There are 4 symmetrical longitudinal rows of cilia on either side of the body which curve round to meet anteriorly. The rounded oral aperture is supported by a basket of trichites. Macronucleus ovoid, centrally placed. There are 3 contractile vacuoles scattered throughout the cell.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)
[ref. ID; 4819]
The genus Odontochlamys is still insufficiently separated from Chilodonella. Foissner (1988) used the following characters: ventral kinety fields depressed, dorsal hump often strongly furrowed or with long processes, postoral non-ciliated field inconspicuous, anterior end of kineties of right field distinctly curved. He also suggested that the apical location of the dorsal brush is probably the most important criterion. This is confirmed by the reinvestigation of Chilodonella convexa Kahl, 1931 which has not only an apical dorsal brush but also meets most of the other criteria. (ref. ID; 4819)
- Odontochlamys alpestris Foissner, 1981 (ref. ID; 4609, 4819) reported author and year? (ref. ID; 1629)
See; Odontochlamys wisconsinensis (ref. ID; 2846)
- Odontochlamys convexa (Kahl, 1931) Blatterer & Foissner, 1992 (ref. ID; 4819 redescribed paper)
See; Odontochlamys wisconsinensis (ref. ID; 2846)
Syn; Chilodonella convexa Kahl, 1931 (ref. ID; 4819)
- Odontochlamys gouraudi Certes, 1891 (ref. ID; 3331, 4861)
See; Chilodonella gouraudi (ref. ID; 3593), Odontochlamys wisconsinensis (ref. ID; 2846)
- Odontochlamys wisconsinensis (Kahl, 1931) nov. comb. (ref. ID; 2846 redescribed paper)
Odontochlamys alpestris Foissner, 1981 (ref. ID; 4609, 4819) reported author and year? (ref. ID; 1629)
See
Odontochlamys wisconsinensis (ref. ID; 2846)
Descriptions
The limnetic population differs only slightly from the terrestrial type material. It is in vivo slightly larger (35-60x20-35 um; average=50x30 um versus 30 to 50x19-25 um), the anterior end is usually more pointed and the dorsal hump projections more distinctly above the flat postoral ventral surface. The kineties of the ventral side consist of more basal bodies and the non-ciliated postoral field is wider. The dorsal brush consists of more (6-9; average=7.4 versus 3-6; average=4.1) cilia. (ref. ID; 4819)
Paratype material
2 slides of protargol impregnated cells have been deposited in the collection of microscope slides of the Oberosterreichisches Landesmuseum in Linz, Austria. (ref. ID; 4819)
Odontochlamys convexa (Kahl, 1931) Blatterer & Foissner, 1992 (ref. ID; 4819 redescribed paper)
See
Odontochlamys wisconsinensis (ref. ID; 2846)
Synonym
Chilodonella convexa Kahl, 1931 (ref. ID; 4819)
Redescription
In vivo 30-40x20-30 um. Acontractile but very flexible. Oval, anterior end bluntly pointed, posterior end broadly rounded. Dorsal hump very conspicuous, having many irregular furrows and prominent anterior slope, distinctly projecting rather deeply depressed postoral ventral surface. Preoral are about 3:1, postoral portion inconspicuously flattened. Macronucleus in posterior half, ellipsoid, contains spherical chromatin bodies surrounding hyaline centre. Micronucleus spherical, in 60% of specimens rather distant from macronucleus. 2 contractile vacuoles, the upper pore close below oral opening between 1st and 2nd inner kinety of right field, the other near posterior end between 3rd and 4th inner kinety of left field. Cytopharyngeal opening in median of cell. Cytopharyngeal rods toothed, form narrow (3-4 um wide at distal end), dorsally and backwards directed funnel; distal half of rods 8-15 um long, proximal portion very thin, in 2 out of 13 specimens cornucopia-shaped. Cytoplasm colourless. Probably feeds on bacteria. Movement slowly gliding, thigmotactic, attaches to soil particles. Cilia of ventral side about 5 um long. Infraciliature very similar to that of other species of genus, differing mainly in morphometric characters. Left ciliary field remarkably small, thus leaving wide gap between posterior ends of right and left ciliary field. Dorsal brush at anterior margin of cell, cilia about 6 um long and remarkable widely spaced. (ref. ID; 4819)
Comparison with related species
Size, contour, shape of dorsal hump, and soil habitat leave no doubt about the identification, although Kahl (1931) has not seen the unique dorsal brush. The brush of O. convexa is most similar to that of O. gouraudi Certes, 1891 (7-12 cilia, Foissner 1988; about 6 cilia, Buitkamp 1977), whose dorsal side has, however, highly characteristic spines. Size and shape of O. convexa are rather similar to that of O. alpestris, whose brush cilia are, however, much more closely spaced. (ref. ID; 4819)
Neotype material
2 slides of protargol impregnated cells have been deposited in the collection of microscope slides of the Oberosterreichisches Landesmuseum in Linz, Austria. (ref. ID; 4819)
Odontochlamys wisconsinensis (Kahl, 1931) nov. comb. (ref. ID; 2846 redescribed paper)
Diagnosis
Size in vivo usually 40x22 um. Four kineties in right field, six in left. Dorsal brush near anterior end in midline of cell, consists of four narrowly spaced cilia on average. Oral basket composed of 14 rods on average. Dorsal hump regular. (ref. ID; 2846)
Descriptions
Size highly variable, in vivo about 25-60x12-30 um. Body flexible but acontractile, distinctly rostrate at anterior left, posteriorly usually slightly narrowed, right margin convex, left sigmoidal. Dorsoventrally flattened about 1.5-2:1, ventral side sometimes slightly concave. Dorsal hump projecting somewhat above ventral surface, outline regular elliptical to bean-shaped, without lobes, rarely with shallow, more or less longitudinal furrows (very likely beginning encystment). Macronucleus ellipsoidal, in vivo about 13x9 um, usually in posterior half of body, contains one central nucleolus, 4-5 um across, and several 1-2.5 um-sized, spherical nucleoli in periphery, Micronucleus globular, 2-2.5 um across, near macronucleus, usually not impregnated with protargol and indistinguishable from roundish cell inclusions. Two contractile vacuoles, one above mid-body with excretory pore usually between first and second innermost kinety of right field, the other slightly behind mid-body with pore close to posterior end of third kinety from left. Cytoplasm rather transparent, contains many tiny, colourless granules and food vacuoles with greenish contents and bacteria. Slowly gliding on substrate particles; thigmotactic. Ventrally ciliary rows (kineties) in two fields, cilia 4-5 um long, in anterior portion slightly longer than in posterior. Kineties of right field arched, innermost row terminates anteriorly at level of cytostome, others extend to preoral kinety; outmost kinety anteriorly rather loosely ciliated, terminates subequatorially while other rows extend further backwards. Kineties of left field of differing length: four terminate at preoral row whole two are shortened and situated in subequatorial area. Dorsal brush close to anterior cell margin, cilia about 5 um long and distally narrowed. Preoral kinety straight or very slightly curved, transverse to main body axis, rather short, covers left end of anterior circumoral kinety. Circumoral kineties arched and Y-shaped, anterior row composed of 12-14, posterior of seven to nine cilia. Oral basket opening subapically in cell midline; oral basket bulbous in protargol-impregnated specimens, directed slightly rightwards and dorsally, cornucopia-shaped, that is, with thin posterior portion, but usually only anterior part recognizable in living (6-12 um long) and protargol-impregnated specimens. Oral basket rods anteriorly without teeth. Encystment as in congeners, conspicuously fast and also induced by cover-slip pressure. (ref. ID; 2846)
Comments
There are several insufficiently described chilodonellids that are similarly sized and shaped as the Antarctic specimens. Thus, instead of erecting a new species, this population was identified with the most similar to these, namely Chilodonella wisconsinensis, published by Kahl (1931) without figure. It differs only slightly from the current specimens by the reduced number of ciliary rows in the left field (four vs. six), the non-curved oral basket, and the deformed dorsal hump. Since these characters are variable and/or difficult to recognize in living cells, they might have been overlooked or misinterpreted by Kahl (1931). The specimens in this study have the dorsal brush, not studied in detail by Kahl (1931), in an apical position and are able to encyst very quickly. These characteristics are typical for Odontochlamys, to which C. wisconsinensis is thus transferred: O. wisconsinensis (Kahl, 1931) nov. comb. In vivo, O. wisconsinensis is easily confused with Chilodonella uncinata (Ehrenberg, 1838) due to its similar size and shape. However, C. uncinata has the dorsal brush in a distinct subapical and left marginal position, as is characteristic for this genus. Odontochlamys wisconsinensis is also rather similar to O. alpestris Foissner, 1981, but has fewer right kineties (four vs. five), more oral basket rods (12-16 vs. about six to eight), and the preoral kinety overlaps the circumoral kineties only slightly because it is composed of fewer cilia (11-14 vs. 14-27 according to the figures in Foissner 1981 and Blatterer and Foissner 1992). Two populations of O. alpestris were previously studied, one each from soil and fresh water. Their main characteristics, the number of oral basket rods and somatic kineties, were very similar and hardly variable, Thus, the Antarctic specimens were separated from O. alpestris at species level. Odontochlamys convexa (Kahl, 1931) Blatterer and Foissner, 1992 differs from O. wisconsinensis by having more (five) kineties in the right field, fewer oral basket rods (eight to nine), a very irregularly folded dorsal hump, and a longer preoral kinety, which is composed of more (about 17) basal bodies and thus distinctly overlaps the circumoral kineties. Furthermore, the dorsal brush, although being composed, as in O. wisconsinensis. Of four cilia, is considerably longer because the cilia are more widely space. Odontochlamys gouraudi Certes, 1891 is readily distinguished from O. wisconsinensis by its spiny dorsal hump, five to six right field kineties, and distinctly longer brush and preoral kinety composed of 6-15 and about 19-27 cilia, respectively. (ref. ID; 2846)