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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Engelmanniella

Engelmanniella Foissner, 1982 (ref. ID; 662 original paper)

Family Orthoamphisiellidae (ref. ID; 7423)

[ref. ID; 4777]
Improved diagnosis; Engelmanniella differs from all known hypotrich genera by the conservation of 3 generations of marginal cirri, during interphase the cirral pattern is rather undifferentiated, while frontal, parabuccal, buccal, and somatic cirri can be distinguished during the morphogenesis. Transverse, frontoterminal (migratory), and caudal cirri are absent. Based on the previous morphogenetic results (Wirnsberger-Aescht et al. 1989) and the data presented here, we improve the diagnosis of the genus Engelmanniella Foissner, 1982 as follows: Infraciliature consisting of frontal, parabuccal, buccal and marginal cirri. Somatic cirral rows comprises 3 generations of cirri. A dorsal kinety develops de novo in the opisthe. The systematic position of the genus is still unclear, it might have some relations to kahliellids and cladotrichids (Wirnsberger-Aescht et al. 1989). (ref. ID; 4777)
  1. Engelmanniella mobilis (Engelmann, 1862) Foissner, 1982 (ref. ID; 662 redescribed paper, 4777, 7423) reported author and year? (ref. ID; 191, 4471)
    Basionym; Uroleptus mobilis (ref. ID; 4777, 7423)

Engelmanniella mobilis (Engelmann, 1862) Foissner, 1982 (ref. ID; 662 redescribed paper, 4777, 7423) reported author and year? (ref. ID; 191, 4471)

Basionym

Uroleptus mobilis (ref. ID; 4777, 7423)

Descriptions

The in vivo aspect of the 4 investigated populations of Engelmanniella mobilis is almost identical, although their soil habitats are quite dissimilar (fertile plain, forest, rice field). Its morphology is characterized as follows: slender, cylindrical shape, posterior end more or less pointed and curved; in vivo c. 120-300x18-30 um; small oral area; particularly short endoral membrane in front of the paroral membrane; many rows of spherical (0.5-1 um in diameter), colourless to yellowish subpellicular granules; somatic cirri consist of 2 basal bodies on the lateral sides and the posterior third of the cell and 4-10 basal bodies in the anterior part. The following data are arithmetic means of all impregnated cells measured from the raw cultures (4 populations; n=68): 22 adoral membranelles; 3 frontal cirri; 1 buccal cirrus; parabuccal cirri; left marginal rows comprising 29, 9, 6 cirri; 3 right marginal rows consisting of 33, 12, 37 cirri; 1 long and 1 very short dorsal kinety; 8 macronuclear segments; 3 micronuclei. (ref. ID; 4777)
One long rightmost ventral cirral row four and the total number of cirral anlagen reduced to six. Dorsal kineties reduced to one long and one short kinety. (ref. ID; 7423)

Comments

Foissner (1982) established the genus Engelmanniella with Englemanniella mobilis (=Uroleptus mobilis Engelmann, 1862) as the type species. The original description of Engelmann is rather incomplete. Thus, Foissner based his identification on a paper of Calkins (1919) who studied a New York variety of this species. The Japanese population matches the American variety of Calkins (1919) better than the Austrian population (Gn) of Foissner (1982). Calkins even mentioned smooth cysts of his form which was later designated by Kahl (1932) as Uroleptus moblis var. americanus. Foissner (1982) included 2 additional species in this genus: E. kahli (Groliere) and E. halseyi (Calkins, 1929). The former species is actually the type species of the genus Perisincirra Jankowski and looks rather different from Engelmanniella. Calkins (1929) distinguished E. halseyi from E. moblis by is capability of stretching out until the length is sixteen times the diameter, the more pronounced pointed posterior end, the subpellicular granules, the 8-26 macronuclear segments, and the 1-2 very large micronuclei. However, particularly long cells usually develop in starve cultures, and highly variable numbers of macronuclear segments occur in the cultured populations. In contrast to cells of the Austrian populations, those of the Turkish population (Tn) often show a single, very large micronucleus. However, smaller micronuclei of variable number were also observed, particularly in Tc. Calkins' description of subpellicular granules is valuable for identification, but these granules might have been overlooked in E. mobilis by Engelmann (1862) and Calkins himself, because he used different methods in earlier studies. The differences mentioned by Calkins (1930) in relation to the nuclear behaviour and the duration of conjugation are probably strain-specific (comp. above). Furthermore, Calkins (1930) mentioned that both forms are identically in their arrangement of the cirral rows. Considering the variability of different natural and cultured populations observed by us, the 2 forms described by Calkins (1919, 1929) are very likely only ecological or cultured variants of E. mobilis and are thus synonymized with this species. (ref. ID; 4777)