mnold1's Favorites

Stentor pyriformis Johnson 1893 from the superficial benthos of the river edge of the freshwater segment of estuarine river Peconic River. Imaged in Nomarski DIC on Olympus BH2S using SPlan 10 NA 0.30, SPlanapo 20 NA 0.70, SPlanapo 40 NA 0.95 and SPlan 100 NA1.25 oil objectives plus variable phone camera cropping on Samsung Galaxy S9+. The cells were visible with the naked eye accumulating on the surface of the water at the side of the sample container. Cells measure from 650-800 um when fully extended. The cytoplasm is densely filled with green algal zoochlorella symbionts. There are also much smaller colorless cortical and cytoplasmic granules. The dense population of zoochorellae obscured the internal morphology of the stentors. Macronuclei could only be observed in markedly squashed cells by evaporation of water from under the coverglass. Most cells had two spherical macronuclei, occasionally three. The morphology of my population was identical to that described by Hoshina et al 2021, however their population was smaller than mine at 220-500 um and their macronuclear count also differed from my population which showed 2 MA: "The average number of macronuclei was 6.1 (range 4–10, n = 9) for freshly obtained samples, whereas four-year cultured cells contained only one or two" (1).

"S. pyriformis is a poorly described species, although S. pyriformis is clearly distinguishable from other Stentor species. The species was first described in 1893 and then appeared in a microbiota report in 1908. However, its next appearance was not until 1994, in the study on revision of the genus by Foissner and Wolfl. As described in the original literature, difficulties in the cultivation of this species may have hindered the research on this species. In Japan, S. pyriformis can be found only in highland highly oligotrophic moors, suggesting that intracellular symbiotic algae would help this species of Stentor survive in such a harsh environment. S. pyriformis was described by Johnson in 18936. This algae-bearing Stentor has separated spherical macronuclei without pigmentation, which certainly differentiates it from other Stentor species. While the most common algae-bearing Stentor, S. polymorphus assumes a slender trumpet shape (often shortened), S. pyriformis never resembles such a slender trumpet, but assumes a pear or short conical shape, even when it is swimming. Among algae-bearing Stentor spp., S. polymorphus and S. pyriformis only are considered colorless species, whereas colored species are S. amethystinus, S. fuliginosus, S. araucanus, and S. tartari. Therefore, S. pyriformis is a clearly discernible species; however, it remains underexplored" (1).

"Cells of S. pyriformis were broadly trumpet-shaped, usually 220–500 × 120–300 µm. This length–width ratio did not change significantly between the cells attached to something and swimming. The cells were colored green due to their endosymbiotic green algae that were distributed along the whole body. A large number of tiny transparent vesicles were present along the ciliary rows immediately under the cell surface. To see the contents, the crushed cells were observed. Symbiotic algae appeared to be typical Chlorella-like algae, but no dividing alga was observed. The algal cells appeared more vividly green when compared to those in P. bursaria, suggesting that they are richer in photosynthetic pigments. The symbiotic algae in S. pyriformis had the same size and morphology as those in P. bursaria. Macronuclei were, in general, large and spherical (ø 20–35 µm). The average number of macronuclei was 6.1 (range 4–10, n = 9) for freshly obtained samples, whereas four-year cultured cells contained only one or two. Micronuclei could not be identified" (1).

My population had two macronuclei rarely three in contrast to the populations of Hoshina et al which had an average of 6.1 macronuclei (range 4-10). Also, Hoshina et al 2021 (1) did not identify micronuclei in their multimodality study of S. pyriformis which included electron microscopy. However, the study of Walker 1908 (2) describes the presence of two macronuclei with multiple small micronuclei scattered within the macronucleus. I detected similar small nodules within the macronuclei to those depicted by Walker 1908 but I am uncertain if these are nucleoli or micronuclei. Hishina et al 2021 describe " a large number of transparent vesicles were present along the ciliary rows immediately under the cell surface (1) which I also found. In addition, Hoshina et al 2021 describe numerous starch granules in the cytoplasm which I believe are also present in my samples. These granules are more than twice the size of the subcortical vesicles.

1. Characterization of a green Stentor with symbiotic algae growing in an extremely oligotrophic environment and storing large amounts of starch granules in its cytoplasm. Ryo Hoshina, Yuuji Tsukii, Terue Harumoto & Toshinobu Suzaki. Scientific Reports | (2021) 11:2865 | https://doi.org/10.1038/s41598-021-82416-9
2. Observations on the Micro-Fauna of an Oregon Pond. Elda R. Walker. Transactions of the American Microscopical Society, Vol. 28, Twenty-Ninth Annual Meeting (Sep., 1908), pp. 75-84

Spirostomum teres Claparède & Lachmann, 1859 from Pussy's Pond, a brackish offshoot of the estuary Acabonac Harbor. Imaged in Nomarski DIC on Olympus BH2 using SPlanapo 20 0.75, SPlanapo 40 0.95 objectives and Splan 100 1.25 oil objective plus variable phone camera cropping on Samsung Galaxy S9+. The cells measure from 480 up to 560 um in average length, have a compact ellipsoid macronuclear nodule, and are brownish in color and highly spirally contractile. A single row of well-developed oral membranelles defines the left side of the long, thin peristomial field, which runs parallel to the main body axis from the anterior end to the cytostome, which is located at 45% of the body length. One stripe of packed cortical granule rows (average 3) between each kinety pair; cortical granules are of different sizes. The contractile vacuole is single and posteriorly located, with a long collecting canal extending along the dorsal side often reaching the anterior end.

"Spirostomum is a genus of ciliated protists that belongs to the class Heterotrichea. It is known for being very contractile. Having been first identified by Christian Gottfried Ehrenberg in 1834, further research has identified eight additional true morphospecies. This bacterivore genus mainly lives in the sediment deposits at the bottom of various aquatic habitats, and members possess rquA genes that could be responsible for their ability to survive in these hypoxic and anoxic environments. They are identifiable by their relatively (to other ciliates) large tubular/flat vermiform bodies. Their life cycle consists of a growth stage, in which they mature, and asexual and sexual reproduction stages. Some species are model organisms for studies on human pathogenic bacteria, while others are sensitive and accurate bioindicators for toxic substances" (1).

"Spirostomum Ehrenberg, 1838 are conspicuous ciliates protists that are easily recognized by their large sizes (500-1000 µm) and elongate bodies, being easily confounded with small helminths. The name Spirostomum refers to the ability these ciliates have to contract in a spiral mode. This type of contraction is due to the presence of post-ciliary, sub-pellicular fibers that arise on the anterior end and spiral in a counterclockwise direction toward the posterior end of the body. Of the eight species that currently comprise Spirostomum, five (including S. minus) possess a moniliform macronucleus" (2). "There are currently eight accepted morphospecies in the genus: S. ambiguum, S. minus, S. teres, S. yagiui, S. dharwarensis, S. semivirescens, S. subtilis, S. caudatum" (1). Among all species of Spirostomum, only S. teres and S. caudatum have a compact macronucleus. S. caudatum is easily separated from S. caudatum by the latter's long thin tail (1). Another old species similar to S. teres is S. ephrussi but according to Repack and Isquith (1974), S. ephrussi is junior synonym of S. teres" (2).

"Spirostomum teres Cláparéde and Lachmann, 1858-1859. [syn: S. ephrussi Delphy, 1939] 150-650 um (avg. 250-450) um long. Length: width ratio about 5-16 (avg. 8-12). 5-15 (avg. 7-10) kineties on each side; usually homogeneous cortical granule rows, variable in number per stripe (2-4). Peristome from 1/3 to slightly more than 1/2 of the body length. Contractile vacuole usually less than 1/5 of the body length. Often brownish. Ellipsoid macronucleus (length: width ratio < 5) in the middle sector of the body, about 20-50 x 5-20 um when stained by Feulgen reaction. A few (1-3) micronuclei 1-2 m long. Molecular analyses suggest that this morphospecies include phylogenetically diverse lineages, some of which are more closely related to S. yagiui and S. dharwarensis; no reliable morphological autapomorphy has yet been detected for these lineages. Found in both fresh- and brackish-water environments. Reported in Europe, central Africa, Madagascar, USA, Brazil, Caspian Sea, India, China and Korea. It sometimes harbors cytoplasmic prokaryotic symbionts" (3).

"Differential diagnosis: 1) Size in vivo 150-600 x20-75 um, mostly 200-400 um, according to DRAGESCO (1960) brackish water forms even reach a length of 880 um. Very contractile; contractile cells more clearly spindle-shaped. 2) Shape moderately broadly cylindrical, somewhat expanded in the middle third, 10-15 times longer than wide. Anterior half distinct, posterior slightly narrowed. Front end slightly beaked, rear end broadly truncated. 3) Macronucleus ellipsoid, about 25-48 x 9-12 um in size, lies in the middle third. 1-2 lenticular, 2-4 um large micronuclei. 4) Contractile vacuole at the posterior end, with a long collecting duct extending forward along the dorsal side. 5) Close under the pellicle, very many spherical, arranged in elongated bands of 2-3 rows each lemon-yellow granules (oil immersion), which give the cell a yellowish tinge. 6) About 25-30 rows of cilia, few in stretched cells, strong in contracted individuals run spirally. 7) The adoral membranelle zone extends from the anterior end to about the middle of the body and bends to the right at the lower end. Oral groove bordered on the right by an undulating membrane. 8] Movement slipping, wriggling and crawling. Floats with rotation around the longitudinal axis" (4).

1, https://en.wikipedia.org/wiki/Spirostomum#cite_note-:3-1

1. Morphology and 18S rDNA gene sequence of Spirostomum minus and Spirostomum teres (Ciliophora: Heterotrichea) from Rio de Janeiro, Brazil. Noemi M. Fernandes & Inácio. D. da Silva Neto. ZOOLOGIA 30 (1): 72–79, February, 2013 http://dx.doi.org/10.1590/S1984-46702013000100009

Trachelophyllum brachypharynx Levander, 1894

"Trachelophyllids prefer terrestrial and semiterrestrial habitats (Kahl 1930; Foissner 1984, 1994, 2005; Foissner et al. 2002), but some have also been found in freshwater (Foissner et al. 1995, 1999) and one species, Trachelophyllum brachypharynx Levander, 1894, was reported from saltwater (e.g., Levander 1894, 1901; Coats and Clamp 2009; Telesh et al. 2009)". I found a population of this species in brackish water from the estuarine pond Pussy's Pond, an offshoot of Accabonac Harbor in the Town of East Hampton, New York. Except for its somewhat smaller size, my observation conforms perfectly to the description of Jang et. al. Size is often variable intraspecies. The lepidosomes forming a mucilagenous cortical surface layer are notoriously difficult to visualize in vivo but you can clearly see the roughened character of the cortex in my photos.

"Size about 380 × 40 μm in vivo, slightly contractile. Shape very narrowly fusiform, with a slightly to distinctly narrowed neck, gradually merging into a broadened trunk. Two ellipsoidal macronuclear nodules usually connected by a fine strand, with two to three broadly ellipsoidal micronuclei close to or attached to macronuclear nodules. Contractile vacuole terminal and comparatively small. Extrusomes filiform, slightly curved and with pointed ends, 30 µm long in vivo. On average, 24 ciliary rows, two anteriorly differentiated into an isostichad dikinetidal dorsal brush: row 1 composed of 40 dikinetids on average, row 2 of 33 dikinetids on average. Lepidosomes hat-shaped and about 4 × 3.7 µm in vivo". "Oral bulge rather conspicuous because distinctly set off from body proper; pin-shaped in extended specimens, while conical in contracted cells; not covered by lepidosomes".

Another marine Trachelophyllum species is Trachelophyllum apiculatum (Perty, 1852) Claparède & Lachmann, 1859. However this species is more flask shaped and has four macronuclear nodules.

Morphology, Ciliary Pattern and Molecular Phylogeny of Trachelophyllum brachypharynx Levander, 1894 (Litostomatea, Haptoria, Spathidiida) Seok Won JANG, Peter Vďačný, Shahed Uddin Ahmed Shazib and Mann Kyoon Shin. Acta Protozool. (2015) 54: 123–135

https://www.researchgate.net/publication/280571553_Morphology_Ciliary_Pattern_and_Molecular_Phylogeny_of_Trachelophyllum_Brachypharynx_Levander_1894_Litostomatea_Haptoria_Spathidiida

Magnification of photos: 400×, 600×, 600×, 400×, 600×
Habitat: filamentous green algae (mostly Mougeotia and Spirogyra) and some organic debris collected from a freshwater pond.
Photo taken with a Celestron PentaView Digital Microscope. According to their website, the FOV (i.e. the diagonal width) at 400× is 150 µm.

Magnification of photos: 100×, 200×, 200×, 200×, 400×, 400×
Habitat: filamentous green algae (mostly Mougeotia and Spirogyra) and some organic debris collected from a freshwater pond.
Photo taken with a Celestron PentaView Digital Microscope. According to their website, the FOV (i.e. the diagonal width) at 100× is 600 µm.

Trachelius ovum EHRENBERG, 1831 EHRENBERG, 1838 from the acidic freshwater kettle pond Chatfield's Hole. Imaged in Nomarski DIC on Olympus BH2S using SPlanapo 20 0.75 and Splanapo 40 0.95 objectives plus variable phone camera cropping on Samsung Galaxy S9+. The cells measure 240 um in length. The following discussions and several figures are adapted from Foissner et al (1995) (1).

According to EHRENBERG (1838), FOISSNER & FOISSNER (1988b) and KAHL (1931a), Trachelius ovum has several safe synonyms, which do not appear in the saprobiological literature: T. cicer SCHRANK- this older synonym was never used and should therefore be suppressed forever for reasons of stability, T. vorax EHRENBERG, Amphileptus rotundus MASKELL, Trachelius Leidyi FOULKE. The exact organization of this common ciliate was previously insufficiently known, although it was reported several times and has been processed using modern methods (DRAGESCO & DRAGESCO-KERNEIS 1986, FRYD VERSAVEL et al. 1975, SONG & WILBERT 1989). The representations are too schematized and incorrect in detail. We have therefore reworked T. ovum for the “Atlas”. This showed that the somatic and oral ciliation is very similar to that of Dileptus. Nevertheless, Trachelius is clearly demarcated from Dileptus namely by the ventro-lateral fossa, where the ciliation is slightly modified and the club-shaped mouth funnel, which consists of a thick layer of the finest fibrils.

Congener comparison: Trachelius subtilis PENARD, which has not yet been sufficiently confirmed, has only 12 contractile vacuoles and no suction cup. Dileptus species usually have a clearly pointed rear end and are always much slimmer. Paradileptus elephantinus lives predominantly in the pelagic of stagnant waters and has a rosary-shaped (moniliform) macronucleus. The characteristics are particularly important for identification are 2, 3, 4 .

Interestingly, I found one individual with two closely abutting oval macronuclei (see end of pictures after sampling site pictures). Trachelius subtilis PENARD, 1922, a species which Vďačný & Foissner (2) synonymized with T. ovum, is stated to have two oval macronuclear nodules. However, Martin Kreutz disagrees with Vďačný & Foissner and writes: "Trachelius subtilis was first described by Penard (1922). The species is smaller than Trachelius ovum and its main characteristic is a two-part macronucleus with a spherical micronucleus in the middle. In 2012 Vďačný & Foissner (2) synonymized Trachelius subtilis with Trachelius ovum with the argument that Penard (1922) possibly only found specimens of Trachelius ovum with a macronucleus constricted in the middle and that this is an observational error. Vďačný & Foissner obviously did not find any specimens with such a constricted macronucleus themselves. However, Penard was a very precise observer and Kahl (1935) also found specimens of Trachelius subtilis, which confirmed and supplemented Penard’s results" (3). Dr. Kreutz's examples do show two clearly separate macronuclear nodules with an intervening micronucleus in contrast to my observation of two closely abutting macronucleuar nodules with no visible micronucleus so I cannot rule out a folded dumbbell-shaped macronucleus appearing as two nodules in my example.

Differential diagnosis
Size in vivo 200-600 x 75-350 um, usually 250-350 um long.
Shape sac-shaped to almost spherical, starving specimens clearly flattened on one side. Proboscis often only about 1/4-, rarely up to 1/2-length, usually curved dorsally. In well fed specimens it becomes a short, stalk-shaped extension. Ventro-laterally a small, difficult to recognize pit that serves as a suction cup.
Macronucleus dumbbell-shaped, often disintegrates into a few spherical parts in postconjugates. Several micronuclei.
Many small contractile vacuoles scattered throughout the cell. Plasma very strongly vacuolated, the strands form a coarse network.
Short, rod-shaped extrusomes in the proboscis along the ridge of the mouth. Cortex thick, with many ellipsoid granules.
About 80-120 longitudinal rows of cilia, some of which extend into the ventro-lateral fossa, where there are several specializations, which are explained in the figure legends. Brush 3-4 rows, on the dorsal side of the trunk, a row extending almost to the end of the body; only clearly visible after silver impregnation and in the scanning electron microscope.
Mouth entrance at the base of the proboscis, surrounded by many very delicate bars that form a club-shaped, thick-walled funnel. To the right of the circumoral row of eyelashes there is a longitudinal row of cilia, on the left there are many short oblique rows of perioral cilia; more precise structure of the oral cilia can only be recognized after silver impregnation.

1. FOISSNER W., BERGER H., BLATTERER H. & KOHMANN F. (1995): Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems – Band IV: Gymnostomatea, Loxodes, Suctoria. – Informationsberichte des Bayer. Landesamtes für Wasserwirtschaft, 1: pp. 208-18
2. VĎAČNÝ P. & FOISSNER W. (2012): Monograph of the dileptids (Protista, Ciliophora, Rhynchostomatia). – Denisia, 31: 1–529.
3. https://realmicrolife.com/trachelius-subtilis/

Magnification of photos: 600×, 600×, 600×, 600×
Habitat: muddy water at the edge of a pond. Associated plants: Typha sp., Verbena hastata. Collected by my friend on November 22, 2022.
Photo taken with a Celestron PentaView Digital Microscope. According to their website, the FOV at 600× is 100 µm.

Cothurnia species found attached to filamentous algae at the shoreline of marine estuary Gardiner's Bay. Imaged in Nomarski DIC on Olympus BH2 using SPlan 40x objective plus variably phone cropping on Samsung Galaxy S9+. Lorica rotund and tapering basally, 47 um long x 30 um wide. Aperture wide, no neck. Aperture border without cleft or collar. External stalk short and slender with no striations; mesostyle short and broad with longitudinal striae; endostyle short without striations. Zooid cylindrical, 56 um long X 25um wide, extending up to one sixth of its length beyond aperture. Diameter of peristomial lip slightly greater than maximum body width. Macronucleus not well visualized but thought to be short sausage-shaped and lying longitudinally in anterior center of body. CV situated near center of infundibulum which is about one third zooid length. Habitat. Marine found attached to filamentous algae. I could find no matching species in Warren and Paynter 1991.

Cothurnia is a genus of freshwater and marine peritrichs in the family Vaginicolidae. It is characterised by living in a transparent tubular lorica. During the feeding or vegetative phase of its life cycle, Cothurnia attaches to submerged surfaces through a short stalk — mostly on the surfaces of fishes, crustaceans and aquatic plants. It is commonly studied for its epibiotic relationship with the host that it is attached to. The etymology of the genus name Cothurnia derives from the ancient Greek word κόθορνος (kóthornos), and from the Latin word cothurnus, meaning "buskin, or high boot". Cothurnia has been noted for its correlation with water quality (especially in water treatment plants). It has been observed a decrease in the prevalence of Cothurnia on prawns as the water quality deteriorates, making it a good indicator of the quality of water in the environment. Cothurnia is often confused with Vaginicola due to their similar morphologies. Vaginicola lacks a stalk and the zooid is attached directly to the lorica.

Cothurnia is mostly sessile, particularly when feeding or asexual reproduction. However, it can be motile when its habitat is disturbed or to search for a habitat with a higher abundance of food. Its mobile stage is called a telotroch and is often mouthless. The cilia of the organism are located on the peristomal disc of the zooid. When feeding, the zooid slowly extends out of its lorica and rhythmically beats its oral cilia to generate a vortex to draw its prey towards its peristomal lip. A typical species of Cothurnia forms a cylindrical lorica to protect the trumpet-shaped zooid. The lorica may be compressed or elongated along the longitudinal axis, resulting in oblate or prolate forms respectively, or it may be compressed along the transverse axis, resulting in dorso-ventrally compressed forms. The shape of these loricae have traditionally been used to distinguish between species, but since they can vary drastically in size and shape, there has been debates regarding the usefulness of the lorica shape as a taxonomic character. When disturbed, the zooid rapidly retracts into the lorica. There is no specific mechanism of aperture closing of the lorica. Towards the posterior end of the lorica, there is a short and slender endostyle that attaches the zooid to the septum of the lorica and a mesostyle that connects the endostyle to the base of the lorica. The scopula produces a short, non-contractile stalk that protrudes through an aperture at the aboral end of its lorica to affix the organism to surfaces. Some species possess smooth and featureless stalks, while others have transverse folds on the surface of their stalks. The stalk forms a basal disc to attach itself like a suction cup.

A revision of Cothurnia (Ciliophora: Peritrichida) and its morphological relatives. ALAN WARREN & JAN PAYNTER. Bull. Br. Mus. nat. Hist. Zool. 57(1): 17-59 Issued 30 May 1991

The suctorian Metacineta mystacina from an ephemeral rainwater puddle on a neglected lawn. Imaged in Nomarski DIC on Olympus BH2S using SPlanapo 40 0.95 objective plus variable phone camera cropping on Samsung Galaxy S9+. This is likely M. mystecina var. brevipes with a very short stalk on the lorica (see below). Actually, Metacineta does not have a true stalk but rather a hollow narrowing extension of the main lorica.

The cell measures 38 um in diameter and the six-sided lorica measures 40 um in diameter. I could only obtain an apical view of the animal despite attemps to wrangle it into a side view by tapping on and moving the coverglass. Thus, I could not assess the presence of and morphology of a basal stalk by optical sectioning through the animal. The lorica is subdivided at the anterior or distal margin into six stellately-arranged acuminate, triangular, valve-like lobes through which the tentacles emerge. I considered a similar species, Solenophrya micraster (Metacineta micraster) whose lorica is attached by its lorica direct to the substratum without an intervening stalk but that species has a pentagonal not hexagonal lorica with 5 tentacles fascicles. There is an ovoid nacronucleus and a single contractile vacuole below the level of the macronucleus.

Differential diagnosis: Only the variety typica is characterized here; are the essential characteristics of the other varieties can be found in the Taxonomy chapter.
1) Shell of the adult sessile specimens 55-250 x 35-80 um. Ratio of length of the wide to the narrow lorica 1:3 to 2:1, usually about 1:1.
2) Cell shape roundish. At the apical end 6 bundles with 6-17 (usually 8-12) tentacles each. tentacle up to 150 um long), distal end spherical.
3) Lorica narrow to broad funnel-shaped and not flattened, with 6 triangular lobes almost at the front completely closed. Tentacles protrude from the radial gaps between the lobes. Width of the stalk, a stem-like narrowing halfway up is about 4-8 um.
4) Macronucleus spherical approximately in the center of the cell. 1 spherical micronucleus.
5) Contractile vacuole subapical .
6) Swarmers 60-70 x 25-35 um, approximately ellipsoid, with 17-28 rows of cilia.
7) Resting cyst in top view, lemon-shaped, with a strong stalk attached to the substrate.

To differentiate the varieties taxonomy. Metacineta micrasler (PENARD) has 5 shell gaps and is usually attached to the substrate without a stalk-like narrowing. In Metacineta macrocaulis (STOKES), the shell is open apically and has 8-9 ribs (no columns) and a relatively long and thin "stem" . Metacineta longipes (MERESCHKOVSKY) is >1000 um long. Metacineta cuspidata resembles the short-stemmed form brevipes can only be clearly distinguished by their long, winding tentacles. Acineta species have a highly compressed shell and only 2 bundles of tentacles. For identification are special Features 1, 3 are important.

Foisner et al write: The taxonomic status of the different forms of M. mystacina is not yet clear. We follow RIEDER (1985), who examined this group in great detail; he distinguishes 5 varieties, viz: typica (6 lorica columns, stem-like part of the housing (= Stylotheca) usually about as long as the width; brevipes (6 lorical slits, stylotheca very short; yoshii (8 lorica gaps, stylotheca short and noticeably thick; bilateralis (6 lorica columns, shell bilaterally symmetrical, stylotheca very short; and angularls (only 2 housing columns, housing bilaterally symmetrical, stylotheca short). MATTHES (1988) looks at the typical form only brevipes and bilateralls as varieties, the others he lists as species. In practice you will be comfortable
all forms mentioned are best referred to as M. mystacina s.l. describe.

Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems, Band IV: Gymnostomatea, Loxodes, Suctoria. January 1995
Publisher: Bayerisches Landesamt für Wasserwirtschaft. Wilhelm Foissner,Helmut Berger, Hubert Blatterer, F. Kohmann. pp 481-7.

Cristigera cirrifera Kahl 1928 , a very interesting cyclidiid scuticociliate from a decomposing boiled wheat seed added to provide food for bacteria and hopefully generate a biofilm in my 2 week-old sample of the superficial intertdal benthos of a new sampling site, a small beach near the boat basin at Moneybogue Bay in Westhampton Beach on the south shore of Long Island. Imaged in Nomarski DIC on Olympus BH2S using Splan 100 0.90 objective with oiled condenser plus variable phone camera cropping on Samsung Galaxy S9+. Thanks to Genoveva Esteban, who has published extensively about this genus, for suggesting the diagnosis.

The cells measure 24 um in length and are barrel-shaped with an unciliated apical plate and a rounded posterior with a single long caudal cilium and a terminal contractile vacuole. The spherical macronucleus is at the anterior of the cell and there is an inconspicuous spherical micronucleus. The population is quite well-fed and the cytoplasm is filled with round refractile food vacuoles. The oral apparatus 1/2 body length. There are 3 very small adoral membranelles arranged one behind the other, right of which an L-shaped undulating membrane, the cilia of which are quite long and when resting the animal forms a striking sail. Movement jumping and sliding; during the often long breaks the cilia are spread apart and the undulating membrane is set up like a sail and food is swirled in. Importantly, we can see an obvious surface covering of long bacilliform ectosymbionts on the cells. Both C. cirrifera and C. vestita have such a bacterial covering but the longer cilia and jumping movement favors C. cirrifera.

From Kahl 1928: Cristigera cirrifera KAHL, 1928 Gr. 24-28 um. uniformly oval to ovoid, with clear depression to the image the half-body-length Mbr. The cirrus-like bristles detach pathologically easy in two (or three?) cilia; they brace themselves crookedly against the cover glass, so they probably serve the jumping movement. What is striking here, although easy to miss, is the constant enveloping the body with a gelatinous shell, which is always covered with coarse, pretty regularly lying baccili are covered; it comes loose when the ciliates die off after it swells (1).

"Cristigera cirrifera Kahl, 1928. This ciliate is probably the organism described by Kahl (1930-35) and also found in other anaerobic marine habitats by Fenchel & Finlay (1991). However, we have observed that the oral infraciliature is unlike the typical Cristigera type. and its somatic infraciliature is also reduced (Figs 22,g;26). Furthermore, the oral polykinetids are not arranged as one kinetosomal file as would be the case in Cristigera, but as three files. A variable number of kinetosomes (usually four) are located between oral polykinetids 1 and 2 (Fig. 26). The paroral membrane starts at the level of the middle of oral polykinetid 1, and has 30-35 zigzagged kinetosomes with an indentation in its course at the level of oral polykinetid 3. The scuticovestige is in two parts: at the end of the paroral mem brane and below the bend of the latter. The somatic kineties are interrupted, leaving a large kinetosome-free gap between the anterior and posterior half of the cell. The kineties in the anterior half each consist of 9- 10 paired kinetosomes, although a few small organisms (- 18 um) have fewer. In the posterior half, some kineties are missing. In Cristigera cimfera from Mariager Fjord, the number of paired kinetosomes per posterior kinety varies, from one to three (Fig. 26). Cristigera cirrifera was found exclusively in anoxic water, in the depth range 16-25m in Mariager Fjord, Denmark. A specific characteristic of this ciliate is the anterior-posterior depression bordered by the last two kineties on the left side (Fig. 26). Similar indentations, aIthough less evident, have been described in other Cristigera species. There is either one or two macronuclei, and one associated micronucleus. The ciliate has a single caudal cilium, and cilia in the posterior half of the cell are stiff when the ciliate stops swimming. The entire cell surface apart from the oral area is covered with ectobiotic rod-shaped bacteria. These bacteria vary in length from 5.7 to 7.6 um (2).

1. Kahl, A., 1931. Urtiere oder Protozoa I: Wimpertiere oder Ciliata (Infusoria) 2. Holotricha außer den im 1. Teil behandelten Prostomata. In: Dahl, F. (Ed.), Die Tierwelt Deutschlands 21. G. Fischer, Jena, pp. 181–398.
2. Microbial diversity and activity in a Danish Fjord with anoxic deep water. Tom Fenchel, Catherine Bernard , Genoveva Esteban, Bland J. Finlay, Per Juel Hansen & Niels Iversen. OPHELIA 43 (1): 45-100 (September 1995).