Chaenea Quennerstedt, 1867 (ref. ID; 2013)
Class Kinetofragminophora: Subclass Gymnostomata: Order Haptorida: Family Enchelyidae (ref. ID; 2013)
Class Kinetofragminophora de Puytorac et al., 1974: Order Haptorida Corliss, 1974 (ref. ID; 4893)

[ref. ID; 2013]
Body shape always elongate, rounded in cross-section. Body highly contractile. Posterior may be rounded or with a narrowing tail region. Anterior always with a short, non-extensible snout-like region which bears many more closely packed cilia (and may also be longer) than the rest of the body. Oral aperture oval, located apically. Body covered in uniform longitudinal arranged ciliary rows which commonly spiral slightly. 3 if these rows have paired kinetosomes in the anterior region close to the snout, these represent the dorsal brush. Trichocysts common, particularly in the snout region. Macronucleus in one or more rounded parts. There is always a large terminal contractile vacuole and some species have extra lateral rows of vacuoles.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)


Chaenea elongata Kahl, 1926 (ref. ID; 1619, 3540) reported author and year? (ref. ID; 2249)
See; Chaenea teres Dujardin, 1841 (ref. ID; 1619, 3540)
Description; In marine. (ref. ID; 2249)
Chaenea limicola Lauterborn, 1901 (ref. ID; 1619, 3540) reported year? (ref. ID; 1618)
Syn; Chaenea similis Zacharias, 1893(?) (ref. ID; 1619, 3540)
Description; Anterior half of body broad; posterior end drawn out into a point; contractile; cytopharynx with trichocysts; many trichocysts in endoplasm; contractile vacuoles in a row; stagnant fresh water. (ref. ID; 1618)
Measurements; 130-150 um long. (ref. ID; 1618)
Chaenea teres Dujardin, 1841 (ref. ID; 1308, 1619, 3540) reported author and year? (ref. ID; 4344)
Syn; Chaenea elongata Kahl, 1926 (ref. ID; 1619, 3540); Chaenea limicola Kahl, 1928 (ref. ID; 1619, 3540); Enchelys stricta Dujardin (ref. ID; 1619, 3540)
Description; The somatic cilia consist of 10-12 (n = 28) curving rows of single kinetosomes evenly distributed around the cell. At the posterior ends of the somatic kineties is the contractile vacuole pore serving the large posterior contractile vacuole. The cell becomes narrow and the kinetosomes are close together at the anterior ends of the kineties. The long cilia of these kinetosomes extend anteriorly over the cytostome and beat synchronously as a unit, independent of the beating of the other shorter somatic cilia. Three short rows of cilia form the dorsal brush just posterior to the zone of densely packed somatic kinetosomes. Found in many gymnostome ciliates, the dorsal brush, or brosse, consists of a few short kineties that are thought to have a sensory function. An everted cytopharynx (= oral dome, rostrum) is at the anterior pole of the cell. Within this cytopharynx are several toxicysts 6-7 um long. Chaenea teres was observed feeding on small flagellates, scuticociliates and oligotrichs. The prey is always small, usually no more than 10-15 um in diameter. In the endoplasm are over 100 small (3-4 um length; 1-2 um width; n = 20) ovoid macronuclei. Micronuclei were not found either with light or electron microscopy in this population. (ref. ID; 4344)
[Ultrastructure]: The somatic cortex - The somatic cilia originate in depressions along furrows on the cell surface. These furrows are called kinetal grooves and the ridges separating them are the cortical ridges. Alveoli are present only under the surfaces of the cortical ridges and are not found in the kinetal grooves. The alveolar space occasionally becomes so reduced that the inner and outer alveolar membranes are pressed together. As in many ciliate with reduced alveoli, parasomal sacs are absent and there is no obvious layer of epiplasm. Mitochondria are abundant in the cortical ridges as well as distributed throughout the endoplasm. Mucocysts are commonly found at the cell surface in both the kinetal grooves and along the cortical ridges. In the kinetal grooves, they are found between the cilia. In the ridges, they project up through gaps in the alveoli to touch the plasma membrane. The attachment of the mucocyst membrane with the cell membrane is similar to that reported for Spathidium (Williams et al., 1981). These mucocysts, ca. 312-370 nm long and 230-260 nm wide, are ovoid and contain a paracrystalline material with a 12 nm periodicity. No other extrusomes are found in the somatic cortex. Occasionally, ectosymbiotic bacteria are found attached to the outside of the cell surface. Each kinetosome is about 455 nm long, as measured from the proximal end to the terminal plate, and 220 nm in diameter. The three infraciliary fibers (postciliary and transverse microtubular ribbons, and a kinetodesmal fiber) are present but there are no subkinetal microtubules proximal to the kinetosomes. Chaenea teres lacks a microfibrillar tela corticalis. The kinetodesmal fiber originates on triplets 7 and 6. It extends from the kinetosomes laterally to the cell's right and slightly anteriorly. As the kinetodesmal fiber moves away from the kinetosome, it projects toward the cell surface under the slope of the cortical ridge, passes laterally below the postciliary microtubules and ends before it overlaps with the kinety to the right. The postciliary microtubular ribbon arises adjacent to triplet 9. From triplet 8, a strut of electron dense material extends to the postciliary microtubules as one does in Spathidium. In cross sections of the kinetosome, the postciliary ribbon extends laterally. In other words, the postciliary ribbon is convergent (Williams & Frankel, 1973). The 6-7 postciliary microtubules extend up into the cortical ridge to the right of the kinetosome. The microtubules then curve posteriorly and continue under the alveolar membranes in stacks of four over three microtubules. As many as 20 microtubules appear in cross-sections of the cortical ridges, so it is estimated that the postciliary microtubules pass posteriorly for a distance of at least 3-4 kinetosomes before terminating. There are two transverse microtubular ribbons. Because they are at angles to each other, it is difficult to get them both in a section at the same time. The 1st ribbon, consisting of five microtubules originates close to triplets 3 and 4. These microtubules extend as a ribbon anteriorly and insert in the cortical ridge to the left of the kinetosome. Electron dense material is associated with the entire length of these microtubules. The 2nd transverse ribbon of three microtubules originates slightly distal to the kinetosome near triplets 4 and 5. This ribbon extends laterally and to the left where it ends in the cortical ridge. No electron dense material is associated with this ribbon of microtubules. (ref. ID; 4344)
[Organization of the oral area]: The most anterior somatic kinetosomes have nematodesmata and their transverse microtubules contributes to the support of the oral structure. These are not oral kinetosomes (oral kinetosomes do not have kinetodesmal fibers) but are somatic or body cilia contributing to the oral structure. Foissner & Foissner (1988) appropriately call such cilia the oralized spomatic kinetosomes. These kinetosomes are more closely packed together than normal somatics and this apparently affects the orientation of the transverse microtubules and kinetodesmal fiber. The 1st transverse ribbon extends forward at a more acute angle and, together with the transverse microtubules from the oral dikinetids, underlies and supports the membrane that lines the everted cytopharynx. The kinetodesmal fiber extends anteriorly past at least three kinetosomes giving overlapping kinetodesmal fibers at the anterior end of the cell. The nematodesmata of the oralized somatic kinetosomes consist of 15-17 hexagonally packed microtubules originated on an electron dense matrix beneath the kinetosomes. These microtubular bundles are directed posteriorly and parallel to the cell surface but at a level proximal to the kinetosomes. There is a pair of oral kinetosomes at the end of each somatic kinety. The 10-12 pairs form a perioral ring around the base of the everted cytopharynx. The two kinetosomes that make up the oral pair are connected to one anterior at the proximal ends. The posterior, right kinetosome is ciliated and lacks all infraciliary fibers except a postciliary ribbon of microtubules that extends posteriorly away from the mouth. The anterior, left kinetosome of the pair is not ciliated. It has a single postciliary microtubules. A nematodesmata and a tangential transverse ribbon of 6-7 microtubules. It should be noted that in ultrastructural studies of ciliates, radial ribbons on oral kinetosomes are usually referred to as postciliary microtubules and tangential ribbons are called transverse microtubules. This terminology is used here to maintain consistency with the published literature. However, the homology between these microtubules and the postciliary and transverse microtubules of the somatic kinetosomes has not been clearly demonstrated. The nematodesmata from the oral pairs and the oralized somatic kinetosomes form the outer boundary of the cytopharynx. No fibrous annulus binds the ends of the nematodesmata together. The transverse microtubules from the nonciliated oral kinetosome together with the transverse microtubules from the oralized somatic kinetosomes extend under the membrane of the everted cytopharynx. They spiral slightly to the cell's right as they ascend the oral dome. The microtubules gradually drop out with the last ones terminating at the apex. Accessory microtubules (also called bulge microtubules arise perpendicular to the transverse microtubules. These accessory microtubules plunge down into the cytopharynx either singly or in small clusters but not in a ribbon. Alveolar membranes underlie the plasma membrane over the oral dome. Mucocysts, mitochondria, ribosomes, toxicysts and phagoplasmic vesicles are distributed within the cytoplasm of the oral area. There is only one type of toxicysts and these are about 0.5 um in diameter and6-7 um long. Their anterior ends project into the tip of the everted cytopharynx. The internal morphology of the toxicyst is similar to what has been described for other ciliates (Hausmann, 1978): there is an inner tube of two layers that is surrounded by a uniformly electron dense, outer tube. The presence of cross-striations in the wall of the outer tube is a unique feature for Chaenea. A membrane surrounds the toxicyst and the space between the membrane and the outer tube contains granular material. The small rod-shaped phagoplasmic vesicles with electron transparent cores may be utilized in forming the food vacuoles of Chaenea. They are found within the circle of nematodesmata in the cytoplasm immediately posterior to the everted cytopharynx. (ref. ID; 4344)
[The cytoplasm] The endoplasm of Ch. teres has an extensive system of rough endoplasmic reticulum. Food vacuoles, developing toxicysts, mitochondria and macronuclei are scattered throughout the cytoplasm. The macronuclei are spherical to ovoid with faintly staining heterochromatin randomly distributed in the nucleoplasm. No micronuclei were observed. (ref. ID; 4344)
Measurements; Chaenea teres from Rehoboth Bay, Delaware, is an elongated ciliate approximately 60 to 115 um in length and 12 to 16 um in diameter (n = 28). (ref. ID; 4344)