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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Laurentiella

Laurentiella Dragesco & Njine, 1971 (ref. ID; 2014)

Class Polyhymenophora: Subclass Spirotricha: Order Hypotrichida: Suborder Stichotrichina: Family Holostichidae (ref. ID; 2014)

Synonym Laurentia Dregesco, 1966 (ref. ID; 2014)

[ref. ID; 2014]
Ovoid body, slightly narrowed posteriorly and expanded anteriorly to accommodate a very large AZM (half body length). 2 rows of marginal cirri and several rows of ventral cirri, The frontal cirri are large and distinct as are the transverse cirri; caudal cirri may be present as well. There are many (11-12) dorsal kineties. 2 large undulating membranes associated with 2 large peristomial funnel. The macronucleus is beaded or moniliform, and each segment is associated with a micronuclei; the beads may or may not be joined. This species feeds voraciously on flagellates and even the testacean Arcella. 2 species have been described.
Quote; Colin R. Curds, Michael A. Gates and David McL. Roberts "British and other freshwater ciliated protozoa Part II Ciliophora: Oligohymenophora and Polyhymenophora" Cambridge University Press, 1983 (ref. ID; 2014)

[ref. ID; 2129]
Note; This genus is related very likely closely Onychodromopsis. Laurentiella is distinguished from O. flexilis by having only one right and left marginal row, an increased number of FVT-cirri and some dorsal kineties originating by multiple fragmentation of at least two primordia. (ref. ID; 2129)
  1. Laurentiella acuminata Fedriani et al., 1976 (ref. ID; 4713, 7685, 7727) reported author and year? (ref. ID; 191, 2129, 4093, 4113)
    Syn; Laurentia acuminata (ref. ID; 4093); Onychodromus acuminatus (ref. ID; 4093)
  2. Laurentiella acuminata Martin et al. 1983 (ref. ID; 4719)
  3. Laurentiella macrostoma (ref. ID; 4093)
  4. Laurentiella monilata (ref. ID; 4093)
    See; Coniculostomum monilata (ref. ID; 4894)
  5. Laurentiella strenua (ref. ID; 4471)

Laurentiella acuminata Fedriani et al., 1976 (ref. ID; 4713, 7685, 7727) reported author and year? (ref. ID; 191, 2129, 4093, 4113)

Synonym

Laurentia acuminata (ref. ID; 4093); Onychodromus acuminatus (ref. ID; 4093)

Descriptions

Laurentiella acuminata is oval with a broad anterior end had a pointed posterior end. The AZM extends to at least half the length of the body. The frontoventral cirri (FV) are arranged usually in six longitudinal rows which form during morphogenesis but become difficult to recognize in adult ciliates. Specimens with a higher number of FV rows of cirri are relatively frequent. Row I is represented only by a paroral or buccal cirrus 1 (BC) located anterior to the paroral apparatus. Row II consists of 4-6 cirri running parallel and very close to the outer (O) and inner (I) paroral membranes, which delimit the right border of the peristome. Row III usually is made up of seven cirri; it runs parallel to row II. These three rows are made of cirri larger than the remaining ones and begin in the same level at the anterior end of the animal. Row IV extends from about the middle of the frontal field to the transverse cirri (TC) and consists of 7-8 cirri. Row V, made up of 6-8 cirri, extends from about the level of the posterior end of the peristome to the transverse cirri. Row VI runs parallel to the right marginal cirri but, in most of the cases, a break in continuity is observed, so that the anterior tract comprises 3-5 cirri and the posterior one, 3-6 cirri. Transverse cirri, usually 5 in number, are located just behind the posterior end of the frontoventral rows, their insertion track being J-shaped. One row of cirri is situated on each margin of the animal. The left marginal row starts on the middle region near the peristomial vertex. Three caudal cirri are located in the posterior end of the body. Dorsal cilia are short and inserted in typical cortical pits arranged into a large number of dorsal kineties, which have a complicated distribution in vegetative forms. Four macronuclear nodes arranged like the number 7 and a variable number of micronuclei situated near them compose the nuclear apparatus, whose DNA content, nuclear cycles, and cell cycle alterations were studied earlier in our laboratory. (ref. ID; 4093)
The cytochemical analysis of the cyst walls. (ref. ID; 7727)