Hemiamphisiella
Hemiamphisiella Foissner, 1988 (ref. ID; 2129, 7307, 7423)
Family Amphisiellidae Jankowski, 1979 (ref. ID; 7307)
Family Oxytrichidae Ehrenberg, 1838 (ref. ID; 7423)
[ref. ID; 2129]
The oral primordium originates in close contact with the ACR. The ACR commences anlagen formation within-row an originates from three rightmost anlagen. All dorsal kineties develop intrakinetally. Usually one postperistomial cirrus developing from third anlage from right. One cirrus left of ACR. Transverse cirri longitudinally arranged, originate from single anlage. Caudal cirri present. (ref. ID; 2129)
[ref. ID; 7307]
The ACR originates from three rightmost anlagen. Usually one postperistomial cirrus develops from the third anlage from right. One cirrus left of ACR. Transverse cirri longitudinally arranged, originate from single anlage. Caudal cirri present. Single species, H. terricola Foissner, 1988 (ref. ID; 7307)
- Hemiamphisiella terricola Foissner, 1988 (ref. ID; 4861, 7307, 7423) reported author and year? (ref. ID; 191)
Hemiamphisiella terricola Foissner, 1988 (ref. ID; 4861, 7307, 7423) reported author and year? (ref. ID; 191)
Descriptions
Divisional morphogenesis: The nuclear apparatus and the marginal rows divide in the usual way. (ref. ID; 7307)
- Stage 1. Stomatogenesis commences near the middle portion of the ACR. The ACR and the postperistomial cirrus appear unchanged.
- Stage 2. A narrow field of basal bodies develops along the left edge of the ACR and extends to the parental undulating membranes. The postperistomial cirrus has appearently dissolved and been incorporated in this field. The buccal cirrus disorganizes to a streak of basal bodies. The cirrus left of the anterior portion of the ACR commences to disaggregate.
- Stage 3. The oral primordium splits: The large posterior portion organizes adoral membranelles, the small anterior portion forms the opisthe's anlagen 1-4. The parental undulating membranes disorganize (proter's anlage 1). The streak formed by the buccal cirrus elongates (proter's anlage 2). The cirrus left of the ACR disaggregates and forms a twisted streak (proter's anlage 3) above the proter's anlage 4, which possibly develops de novo or from migrating basal bodies of anlage 2. The cirri of the middle segment of the ACR disorganize and form V-shaped streaks (proter's and opisthe's anlagen 5, 6); however, we cannot exclude that anlage 6 develops de novo.
- Stage 4. The formation of the opisthe's adoral zone of membranelles proceeds posteriorly. All cirral streaks align and lengthen. Six anlagen each in the proter and opisthe are recognizable and organize in the same manner. Anlage 1 splits longitudinally to form the paroral and endoral membrane as well as the first frontal cirrus. Anlage 2 develops the buccal cirrus and the second of frontal cirrus. Anlage 3 develops the third frontal cirrus and the cirrus left of the ACR. Anlage 4 develops cirri which migrate in two directions: the anterior cirri migrate to the right to align with anlage 5; the posteriormost cirrus migrates posteriad to become the postperistomial cirrus. Rarely do two, three or no postperistomial cirri develop. Likewise, anlage 6 develops cirri which migrate in two directions: the posterior cirri migrate posteriorly to become the transverse cirri; the anterior cirri migrate anteriorly and to the left and align with anlage 5 and the anterior cirri of anlage 4 to form the ACR. This process of forming the ACR from three segments is also well recognizable in late dividers. New dorsal kineties develop within the old ones. Basal bodies aggregate at the posterior ends to form inconspicuous caudal cirri.
- Stage 5. The cirral migration as described in stage five proceeds and cytokinesis commences. The postperistomial cirrus reaches its final position usually in the post-divider. (ref. ID; 7307)
Remarks
Uroleptoides qingdaoensis Song Weibo & Wilbert, 1989 is possibly a junior synonym of Hemiamphisiella terricola. The frontoterminal cirri of this species belong very likely to the right marginal row. (ref. ID; 7307)
Morphogenetic processes are very similar to Pseudouroleptus caudatus. Differences are in the ventral anlagen development in row six, which has fewer cirri and some of them contribute to the neokinetal anlagen development and some migrate anteriorly. H. terricola is the first in a series that show such a migration in the rightmost ventral row (usually named front-terminal cirri or anterior segment of the amphisiellid cirral row). It is also the first in a series that reduces the number of cirri in the two rightmost ventral rows successively as they become higher evolved. (ref. ID; 7423)
Occurrence
This species was found in February 1987 in mosses covering the soil of an autochthonous pine forest (Callitris sp.) near Adelaide (Tailem Bend; Australia). (ref. ID; 7307)