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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Trochiliopsis

Trochiliopsis Penard, 1922 (ref. ID; 2013)

Class Kinetofragminophora: Subclass Hypostomata: Order Nassulida: Suborder Microthoracina (ref. ID; 2013)

[ref. ID; 1601]
The organization of Trochiliopsis, especially the general appearance of the infraciliature and the location and structure of the oral apparatus, allows a classification close to the genus Stammeridium. These similarities might have induced Kahl (1931) to synonymize Trochiliopsis with Trichopelma Levander and Leptopharynx Mermod. There are just sufficient differences in the location of the preoral kineties, the paroral membrane, and the shape of the anteriormost region for separating these two genera. Furthermore, by a trivial twist of some organelles of Trochiliopsis, the typical organization of the genus Stammeridium can be achieved. (ref. ID; 1601)

[ref. ID; 2013]
Body outline shape oval with anterior curved slightly to the right terminating in a pointed beak-like region. Body strongly compressed laterally and covered in a rigid longitudinally ribbed armour. Somatic ciliation reduced to ventral surface and these arise between ribs. There is a group of cilia beneath the beak-like anterior. Macronucleus centrally located with single contractile vacuole above it. There are many characteristic trichocysts present.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)
  1. Trochiliopsis australis Foissner et al., 1988 (ref. ID; 1599 original paper)
  2. Trochiliopsis opaca Penard, 1922 (ref. ID; 1601) reported author and year? (ref. ID; 4611)
    Syn; Leptopharynx opaca Detcheva, 1972 (ref. ID; 1601); Trichopelma opaca Kahl, 1931 (ref. ID; 1601)

Trochiliopsis australis Foissner et al., 1988 (ref. ID; 1599 original paper)

Diagnosis

In vivo ca. 35-45x18-30 um; left side with four prominent ridges; anterior segment of somatic kinety 2 with 13 kinetosomes on the average; total number of kinetosomes ca. 200. (ref. ID; 1599)

Descriptions

Terminology is according to Augustin et al. Body compressed laterally (ca. 2:1), outline oval, anteriorly curved slightly to the ventral side terminating in a pointed beak-like region below, in which the total apparatus is located. Pellicle rigid, colorless, opaque, Somatic kineties in deep, crenulated furrows, especially on the left side, where four prominent ridges occur that are flattened anteriorly and posteriorly, except for the central furrow, which remains deepened and is slightly widened posteriorly where two cilia emerge. Macronucleus spherical, hyaline, centrally located, with large chromatin bodies (nucleoli?). Micronucleus spherical, next to the macronucleus. Contractile vacuole located centrally let of median; its contents are discharged via a distinct canal whose pore is situated at the end of the paroral membrane. Cytoproct slightly posterior to the contractile vacuole, visible in vivo as a clear vesicle and as black line in silver-impregnated specimens. Cytoplasm without special inclusions. Extrusomes ca. 3 um long, fusiform, scattered over the whole body in or near the ridges between the furrows. Feeds on bacteria, which are digested in small, hyaline food vacuoles. Movement slow, often crawling on detritus. Length of cilia ca. 8 um. Six arched somatic kineties (K1-K6), between K4 and K5 an additional strongly reduced kinety composed of only ca. five kinetosomes. Most kinetosomes paired, but about half of pairs with only single cilium. Thus, different appearance in vivo from that of silver-impregnated specimens. Three preoral kineties (P1-P3); P2 and P3 distinctly marked by lattice-like silverlines. An x-kinety between K6 and the paroral membrane, present in T. opaca, not found in T. australis (absent or not impregnated). Adoral membranelle at the oral peak near and above the cyrtos; seems two rows with three to four kinetosomes each. Paroral membrane with 7-11 pairs of cilia. Cyrtos large, visible in vivo (unlike that of T. opaca), laterally compressed, made of many fine rods with stronger argyrophilic zone a few micrometers behind their distal ends. Thus, in protargol preparations cyrtos often seemingly begins just right of preoral membrane. Silverline system granular, except for wide-meshed part between the preoral kineties. (ref. ID; 1599)

Comments

The genus Trochiliopsis belongs to the Microthoracidae and is closely related to Stammeridum, from which it differs mainly by the location of the preoral kineties. Until, recently, it was monotypic with T. opaca Penard, 1922, as type species. Trochiliopsis australis differs from T. opaca in several biometric characters. The total number of kinetosomes is ca. 200 in T. australis and ca. 100 in T. opaca. The best morphologic characters distinguish these two species are the prominent ridges on the left side, which is nearly flat in T. opaca, and the anterior segment of K2, which in T. opaca consists of only two kinetosomes. (ref. ID; 1599)

Type locality

Activated sludge, Glenelg water treatment plant, Glenelg, South Australia. (ref. ID; 1599)

Trochiliopsis opaca Penard, 1922 (ref. ID; 1601) reported author and year? (ref. ID; 4611)

Synonym

Leptopharynx opaca Detcheva, 1972 (ref. ID; 1601); Trichopelma opaca Kahl, 1931 (ref. ID; 1601)

Descriptions

Freshwater. In vivo circa 30-40(-50)x17-20 um. Body outline oval, anteriorly curved slightly to the ventral side terminating in a pointed beak-like region (peak). Body strongly compressed laterally. Somatic kineties in deep, crenelated furrows, which terminate near the oral peak. Macronucleus spherical, more or less centrally located, in vivo hardly discernible. Micronucleus closely attached to the macronucleus. Contractile vacuole centrally located, close to the right lateral surface, diameter about 4 um; contractile vacuole pore at the end of the paroral membrane. Cytoproct slightly posterior to the contractile vacuole pore, visible as black line in dry silvered specimen. Pellicle regid, colourless, opaque. Extrusomes about 3 um, fusiform, scattered over the whole body in the ribs between the furrows, show four anchor-like processes at the distal end in the exploded phase. Probably feed on bacteria, but no food vacuoles were found. Slow, trembling and swaying movements. Length of cilia 8-10 um. Six somatic kineties (K1-6), three preoral kineties (P1-3), and a short x-kinety. K1 anterior with 8-10, posterior with 4, K2 anterior with 2, posterior with 5-6, K3 anterior with 12-16, posterior with 5-8, K4 (anterior) with 6-8, K5 anterior with 3-4, posterior with 2, K6 with 10-12 kinetosomes. At the end of K4 and in the middle of K5 sometimes a single unciliated kinetosome, respectively. Basal bodies of K1-5 mostly paired, K6 always with single kinetosomes. Preoral kinety 1 with 4-5 pairs, preoral kinety 2 constantly with 5 singles, and preoral kinety 3 constantly with 7 singles. x-kinety with 1-2 paired basal bodies located left of the posterior end of the paroral membrane. Probably only two adoral membranelles, located at the oral peak. Anterior adoral membranelle most likely built up two rows, posterior one probably by three rows of kinetosomes. Paroral membrane with 8-9 paired basal bodies. Cyrtos invisible in life even with interference contrast, but slightly impregnated with protargol silver. Silverline system granular or very fine-meshed. (ref. ID; 1601)