Favoritos de closterium_mysterium

Violet-black cells in gelatinous sheaths at the surface of a layer of gelatinous cyanobacteria, growing on a lost sock in the mud of a flooded abandoned limestone quarry. I'm not certain that these photos are all of the same organism - some are dark violet and some are more strongly just black. The violet capsule absorbs so much light that it is difficult to induce autofluorescence in the chlorophyll of the cell inside. The first picture shows the violet layer beside some Trentepohlia. The various pictures demonstrate the colours in contrast to some of the other species present (Hassallia, Trentepohlia). Cells themselves are 3-6 µm and the capsules are 6-12 µm. The surface violet-black layer covers a deep layer of gelatinous cells inside lamellated mucilaginous sheaths, of different generations, that I now think are another species entirely.
Part of a gelatinous community: https://inaturalist.ca/observations/208411876.

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

Cryptomonas (Chilomonas) paramecium Ehrenberg 1832. A bloom from the acidic freshwater kettle pond Chatfield's Hole fed with boiled wheat seeds. Imaged in Nomarski DIC on Olympus BH2S using SPlan 100 1.25 oil objective plus variable phone cropping on Samsung Galaxy S9+. As Jara Kubin points out, the correct name after molecular analyses is Cryptomonas paramecium, the species is a regular member of the genus, but without chlorophyll.

Hoef-Emden, K. & Melkonian, M. (2003). Revision of the genus Cryptomonas (Cryptophyceae): a combination of molecular phylogeny and morphology provides insights into a long-hidden dimorphism. Protist 154: 371-409

Genus: Similar to Cryptomonas in general body form and structure, but colorless; without pyrenoid; "cytopharynx" (gullet) deep, lower half surrounded by granules (ejectisome/trichocyst); one contractile vacuole anterior (Kudo, 1966). Chilomonas does not have chromatophores (pigment-containing structures) and lives by ingesting organic matter.
Species: 20-40 μm long. Posteriorly narrowed; slightly bent 'dorsally'; 30-40 μm long, 10-15 μm wide; widely distributed in stagnant water (Kudo, 1966).

Free-swimming, biflagellate monads, generally obovoid often with a recurved posterior sometimes produced to acutely pointed; not known to produce palmelloid colonies. A longitudinal furrow extends posteriorly from the vestibulum and transforms into a sack-like gullet lined with many rows of ejectosomes. With a single nucleomorph but lacking a chloroplast and pyrenoid; with a prolific accumulation of peripheral starch granules. Periplast with a laminate inner component and a superficial layer of fine fibrillar material. Sexual reproduction is unknown; reproduction being through simple cell division. Cyst formation is unknown.

Stentor igneus Ehrenberg, 1838 from the acidic freshwater kettle pond Chatfield's Hole after feeding the culture with boiled wheat seeds. Imaged in Nomarski DIC on Olympus BH2S using SPlanapo 40 0.95 and SPlan 100 1.25 oil objectives plus variable phone cropping on Samsung Galaxy S9+.
Rose-colored or colorless; macronucleus oval; ciliation uniform. This small, reddish-pigmented freshwater species is well defined due to the redescriptions by Foissner (1980) and Song and Wilbert (1989). Foissner et al. (1992) reviewed the data available on its morphology and ecology. Stentor igneus lacks symbiotic algae and has two synonyms: S. roseus and S. ruber. Measurements. 200-400 um long.

Part of a mixed community of cyanobacteria and lichens that have colonized a sock, embedded in the mud of a flooded abandoned quarry. The filaments of Scytonema are embedded in thick yellow sheaths, 12 to 20 microns wide. The epifluorescence photos reveal the form of the filaments within the sheaths.

culture from temporary mud puddles and wet soil with algae in old orchard land W of Tavira, Portugal; collected 3 April 2024
Video on my post to fb group Amateur Microscopy: https://www.facebook.com/1300443920/videos/pcb.2592299670951432/800319331606585

Paramecium nephridiatum V. Gelei, 1925 from the brackish estuarine pond Pussy's Pond, an offshoot of Acabonac Harbor. The population arose after feeding the culture with boiled wheat seeds. Imaged in Nomarski DIC on Olympus BH2S using SPlanapo 40 0.95 and SPlan 100 1.25 oil objectives plus variable phone camera cropping on Samsung Galaxy S9+.

The cells measure from 100-165 um in length. There is a large oval macronucleus usually situated slightly anterior to the cell equator and 3-4 small endosomal-type micronuclei can be observed with exact focus in the anterior end of the cell remote from the macronucleus- an important specific character of P. nephridiatum according to Fokin et al 1999 (1) The oral apparatus is situated posterior to the macronucleus with the cytostome roughly equatorial. There is an inconspicuous tuft of long caudal cilia. The two contractile vacuoles, one anterior and one posterior, have up to 15 short radiating canals and 2-3 excretory pores- another important specific characteristic of P. nephridiatum (1). There is a dense investment of subpellicuar extrusomes. The pellicle is divided into rectangular spaces on optical sectioning of the surface, a feature not mentioned by Fokin et al 1999. These features point strongly to P. nephridiatum. However, the more posterior location of the oral opening (as opposed to slightly anterior to the middle of the cell) and the peculiar pellicular division into rectangular spaces suggest that this might be a cryptic species of P. nephridiatum. Indeed, Przyboś et al 2019 describe 6 cryptic species within P. nephridiatum (2)

The cell shape with its rounded posterior end, and broad anterior part is of the "bursaria" type (Wichterman 1986) or "woodruffi" type according to Jankowski (1969). The oral opening is situated a little anterior to the middle of the cell. The cell surface is uniformly ciliated except for several long caudal cilia located close to the posterior end of the dorsal side, but not on the top. The abundant subpellicular trichocysts are distributed uniformly. Specimens were about 145 x 47 um long in vivo but shrank 10% after the silver nitrate impregnation. In silver-impregnated specimens, there were ~38 rows of ventral kineties and ~35 dorsal kineties. The preoral suture is distinct, but the postoral suture is very obscure. The cytoproct is situated in the posterior third. The vestibular zone is conspicuous and is terminated by the distinctive shape of the buccal opening. Two peniculi and open quadrulus are located on the dorsal and left wall of the buccal cavity. The endoral membrane is situated along the entire right edge of the buccal opening but its dikinetids are not recognizable in all specimens. It has 15 dikinetids on the average. The buccal cavity size various around 30 um. On the dorsal side of the body the contractile vacuole pores are very distinctive both on impregnated specimens as well as in living cells. Usually, both contractile vacuoles have more than one pore each, typically two or three. However, we have found two stocks (WCh-1 and WS-12) where one of the contractile vacuoles quite often (up to 50%) had only one pore. Both contractile vacuoles usually have 8-14 collecting canals, ten on average. Numerous crystals were very often found in the cytoplasm, but their quantity and location varied, probably depending on the culture conditions. The nuclear apparatus is located in the anterior part of the cell. One slightly ellipsoid or ovoid macronucleus, ~30x36 um in living cell and ~17x23 um in stained cells, on average, resides just anterior to the equator of the cell. In Feulgen-stained cells the macronucleus has a very intense colour. The three to four spherical micronuclei of the "endosomal" type (Fokin 1997), ~3 um in diam. (on average) are distributed irregularly along the anterior part of cell. Endocytobiotic bacteria are often found in the cytoplasm (Fokin 1989) and can also be found in the perinuclear space and in the macronucleus (Fokin 1989; Fokin and Sabaneyeva 1997)" (1).

"Swimming behavior - During swimming this species spirals on its long axis in both directions (Fokin 1987). We could not find any simple triggers (food, time) for changing this swimming direction. Typically, "left spiral swimmers" and "right spiral swimmers" were present at the same time in the culture. During the several years of investigation of this trait there was some preference of the cells from the same stocks to spiral in the left direction. Remarks- Gelei (1925) described a new species of Paramecium, Paramecium nephridiatum, based on the material which he had found in his laboratory aquarium. This population was in fact a mixture of the new species and Paramecium caudatum (Gelei 1938). This was the reason why some features of the new ciliate were similar to P. caudatum so that no one recognized this new species in nature, though reference to P. nephridiatum was made by Kahl (1931) and Kalmus (1931). Gelei (1938) redescribed the species from a native population (Tisza River, Szeged, Hungary) using a "clean culture". For unknown reasons, this new description did not attract the attention of protozoologists and in all subsequent reviews, P. nephridiatum was considered a nonvalid species (Vivier 1974; Wichterman 1953, 1986) even when the article of Gelei (1938) was listed in the references. Only once was P. nephridiatum mentioned in a short abstract as a species living in Florida, USA (Bovee 1983), although characters of the species were not listed in this publication. Since 1983, one of us (S. F) has repeatedly collected a species of Paramecium with multiple contactile vacuole pores, which is a distinctive trait of P. nephridiatum, although it was considered for a time as a feature of Paramecium woodruffi (Agamaliev 1983; Fokin 1986), Jankowski (pers. commun.)" (1).

"Occurrence and ecology- A number of stocks of P. nephridiatum were isolated from the sea shores of northern Europe: the North, Baltic, White, and Barents Sea coasts. It was detected during sampling in Woods Hole, MA, USA, Atlantic Ocean and on Sakhalin Island, Sea of Okhotsk. The salinity of these samples varied from 1.5-32 % The species was also found in a fresh-water body in Jerusalem Zoo, Israel. Samples were taken mainly during the summer, from mid-April (Wood Hole) to November (North Sea coast).

Sampling of the same wild population of P. nephridiatum (Sredny Island, White Sea, Russia) has been repeated every year since 1990 to observe long-time changes in the population, as well as the euryhaline ability of the species. This population was present at salinities from 4-35% and in the temperature range from 10-25” C. Very often the populations of P. nephridiatum occurred at the lower limit of oxygen concentrations. They were mainly feeding on bacteria. In the same samples these other ciliates were usually found: Prorodon sp., Frontonia marina, Metopus sp., P. calkinsi, P. woodruffi, and sometimes P. duboscqui" (1).

1. Sergei I. Fokin, Thorsten Stoeck, and Helmut J. Schmidt; Rediscovery of Paramecium nephridiatum Gelei, 1925 and its Characteristics. J.Eukaryot.Microbiol. 46(4):416-426, 1999
2. Evaluation of the molecular variability and characteristics of Paramecium polycaryum and Paramecium nephridiatum, within subgenus Cypriostomum (Ciliophora, Protista). Ewa Przyboś, Maria Rautian, Alexandra Beliavskaia, Sebastian Tarcz . Mol Phylogenet Evol . 2019 Mar:132:296-306

Acineria uncinata Tucolesco, 1962 from the freshwater pond Kellis Pond which appeared after feeding the culture with boiled wheat seed. Imaged in Nomarski DIC on Olympus BH2 using SPlan 100 1.25 oil objective plus variable phone camera cropping on Samsung Galaxy S9+. The cell measures 48 um in length. There are three visible somatic kineties which differentiates this species from A. incurvata which has 11 somatic kineties. Augustin, Foissner & Adam 1987 describe 3 right kineties while Martin-Cereceda, Serrano and Guinea 1995 describe 4 (rarely 5)- 2 left and 2 right. This, and the presence of the short oral slit being restricted to the anterior pole are discriminatory. There are two spherical macronuclei with a large intercalated micronucleus between them.

"Acineria uncinata is a lanceolate ciliate with a short oral slit restricted to the anterior region, and rolled up forming a characteristic overlapping in the anterior area at the left side of the cell. Sizes range between 26-38 um in length and 11-17 um in width in OsO4 fixed specimens. The nuclear apparatus consists of two nearly spherical macronuclei, closely together, and one large micronucleus between them. A single contractile vacuole is at the posterior end of the cell. Extrusomes are regularly placed at the anterior end of the cell, and other are dispersed at the cytoplasm. Somatic infraciliature is composed of four kineties (rarely five) which present a different arrangement at both sides of the cell. The two right ones (rk1, rk2) have long cilia and show kinetodesmal fibers, while the two left somatic kineties (lk1, lk2; a third left kinety is sometimes present) possibly lack such fibers. A kinetal segment with short clavate cilia, composed of pairs of kinetosomes, is located at the left dorsal side. Three perioral kineties are located at both sides of the oral region. Left perioral kinety (pk1) shows kinetosomes with slight fibers which could correspond to transverse microtubules. At right side, two kineties accompany the oral slit, one of them (pk2), short in length, seems to be formed by pairs of kinetosomes whose fibrillar derivates did not stain, while the other kinety (pk3), extending to the posterior end of the cells, is formed by kinetosomes with long cilia and conspicuous kinetodesmal fibers. This perioral kinety is thus very likely a somatic ciliary row except for its anterior region" (1).

"Acineria uncinata Tucolesco, 1962 Brackish and freshwater. About 35-55 um. Body lanceolate without lateral edge. Anterior pole overlapping towards the left side. Two spherical macronuclei showing a clearer zone at their central region. Sometimes a single, elongated, tapered nucleus. Contractile vacuole terminal, often surrounded by a group of smaller vacuoles. Cytostome a straight and short slit restricted to the rolled up anterior pole. Can therefore feed only on small prey (flagellates). Three somatic kineties on the right side with 20-22 cilia each. Cilia at the ventral margin of the anterior third transformed to regularly curved crotchets. Occurence and Ecology. This species was found in summer 1954 in a small dirty brackish puddle near Lake Tekirghiol and in mesosaprobic freshwaters of Bucharest. Tucolesco (1962) separated this species from A. incurvata by the non-overlapping post-oral dorsal margin. However, in A. incurvata the situation is rather similar. Thus, we propose the following characters for discrimination from A. incurvata: the presence of only three somatic kineties on the right side, the (probably) unciliated left side, and the short oral slit being restricted to the anterior pole. Unmentioned since description. Note after proof reading: This is a valid species which we rediscovered recently" (2).

1. Mercedes Martin-Cereceda, Susana Serrano, and Almudena Guinea; Occurrence of Acineria uncinata in Activated Sludge Plants: Morphology and Relationship with Physico-Chemical Plant Parameters. Arch.Protistenkd. 146:79-84, 1995
2. Revision of the genera Acineria, Trimyema and Trochiliopsis (Protozoa, Ciliophora). H. Augustin, W. Foissner & H. Adam. Bull.Br.Mus.Nat.Hist. (Zool) 1987 52(6): 197-224

Stentor muelleri EHRENBERG, 1831 from Pussy's Pond, a brackish offshoot of the estuary Acabonac Harbor. Swimming and fully contracted cells. Imaged in Nomarski DIC on Olympus BH2 using SPlanapo 40 0.95 and SPlan 100 1.25 oil objectives plus variable phone camera cropping on Samsung Galaxy S9+.

The extended cells measure from 400 up to 640 um in length. Individuals appear brownish in color and have a moniliform macronucleus composed of a chain of up to 20 ovoid to ellipsoid nodules. I could not observe the lorica since these samples have been disturbed [see discussion below item 8].

" Stentor has a mighty oral appar4tus on the margin of the
broad end. It is cornposed of hundreds of adoral
membranelles (plates of closely spaced cilia acting
together) which are, on the inner side, accompanied by a
single row of cilia, the so-called undulating membrane. The
ciliary plates, which are composed of 25 pm long cilia and
beat 30 times per second, form a spiral band, the so-called
adoral zone of membranelles, which plunges into a conical
buccal cavity leading to the cytostome (mouth proper).The
metachronal beat of the membranelles generates a strong
current swirling food organisms with a velocity of 800 pm s-1 into the buccal cavity" (5).

"Stentor muelleri Ehrenberg, 1831 10-20 macronuclear beads. Slenderly trumpet shaped and 500-1000 um (rarely up to 3 mm) long when fully extended. Mainly in freshwater, but also in estuaries. Recorded from Europe, North America and China . A detailed description and discussion of synonymy, morphology and ecology can be found in Foissner et al. (1992). This freshwater species is well defined by its moniliform macronucleus and the absence of pigmented cortical granules. It has-30-50 somatic kinetics and -10 peristomial ciliary rows. Stentor muelleri has two junior synonyms: S.felici and S.katashimai" (1)

Differential diagnosis from (2)

Elongated individuals in vivo up to 3 mm, usually 500-1000 um long.
Sessile, slim, trumpet-shaped, usually slightly curved. Contracts in an inverted pear shape.
About 10-20 spherical macronucleus parts, which in elongated individuals have a rosary-like form, forming a chain about half the length of the body. 10-17 micronuclei .
Contractile vacuole on the left wall of the oral funnel, with one collecting duct reaching far backwards.
In the plasma and between the cilia, very dense, colorless, granules about 0.5 pm in size. Appears yellowish to brownish at low magnification. No symbiotic algae.
Number of ciliary rows (about 70?) unknown.
The adoral membrane zone extends into the mouth in a spiral to the right. Number of the adoral membranelles unknown. Floor of the mouth with about 20 ciliary rows.
8] Sometimes found with extended, thigmotactic cilia in a 200-1000 um (usually 300-500 um) long, sac-shaped to bottle-shaped, slimy, sometimes very hyaline shell (case usually only noticeable in cells that have been undisturbed for a long time; then often densely covered with detritus).
"Comparisons S. polymorphus and S. coeruleus also have a rosary-shaped macronucleus. The former is colored green by symbiotic algae, the latter has light to strong blue granules between the ciliary rows. Smaller one (500-1200 um) and like S. muelleri uncolored S. roeseli, the macronucleus is rope-shaped. Characteristics 3 are particularly important for identification, 5 important" (2). " Stentor katashimai Kumazawa, 1973 has the main characteristics of s.muelleri, from which it is said to differ by the lack of a lorica, a more stocky shape and the possession of a buccal pouch (Kumazawa, 7974)" (1). "Stentor cornutus Kumazawa 2002 is more conical in shape when extended, while S. muelleri takes a characteristic, slender shape (Kahl, 1935), which is more like an uncoiled trombone (Tartar, 1961a) rather than a trumpet. Stentor cornutus never forms the cylindrical case that S. muelleri usually has when it is attached. The stiff cilia in S. cornutus are shorter, and much less conspicuous than those in S. muelleri. The macronuclear nodes are fewer and more spindle-shaped in S. cornutus than those in S. muelleri, which has more rounded, bead-like nodes" (3).

Fernandes et al 2012 reported a population of Stentor polymorphus devoid of symbiotic algae. They based their diagnosis largely on the absence of loricae in their population and by the presence of a large peristomial pouch (4). The lorica is not always seen in S. muelleri and Foissner et al 1992 attached little importance to its presence (2). The buccal pouch was discounted by Foissner et al 19922 (2) as being a weak character insufficient to discriminate species (2). However Kumazawa 2002 disagrees and stressed presence of the large pouch as an important discriminatory character between their new species S. cornutus as well as S. katashimai (3). Kumazawa 2002, in his figure 1, illustrates the large buccal pouch in S. polymophus (figure 1a) and the lack of same in S. roseli (figure 1b) (3). My observation here has an identical buccal cavity to Kumazawa's figure 1b which he states demonstrates a species lacking the buccal pouch. This serves to differentiate my observation from an aposymbiotic population of S. polymorphus. In addition, the S. polymorphus population of Fernandes et al 2012 had an in vivo length of 850-2000 um, quite a bit larger than my population of S. muelleri at 400-640 um (4).

"Occurrence and distribution: Approximately equally common in stagnant and flowing waters, much rarer than Stentor roeseli. SCHMARDA (1846) found it in all seasons and slow-flowing waters near Vienna. Also in the mesosaprobic samples from Amper near Munich fairly regularly and with a focus on appearing in May/June. We found 1 specimen in the activated sludge. According to ALBRECHT (1984), S. muelleri is oligo- to mesoeuryhaline (see also the evidence from KAHL 1933) in the mouth of the Weser, from BIERNACKA 1962 in the Bay of Danzig, by RIEDEL-LORJE 1981 in alpha to betamesosaprobic samples Elbe Estuary and by JONES 1974 from an estuary in the USA with (0.2-3% salinity). So far only in Europe and Asia (SHEN YUNFEN et at. 1988) and North America" (2).

1. Revision of the genus Stentor Oken (Protozoa, Ciliophora) and description of S.araucanus nov. spec. from South American lakes W.Foissner and S.Wölfl. Journal of Plankton Research Vol.l6 no.3 pp.255-289. 1994
2. Foissner,W., Berger,H. and Kohmann,F. (1992) Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems-Band II: Peritrichia, Heterotrichida, Odontostomatida. Informationsberichte des Bayer. Landesamtes für Wasserwirtschaft, May 1992, pp. 351-4
3. Notes on the taxonomy of Stentor Oken (Protozoa, Ciliophora) and a description of a new species. HIDEO KUMAZAWA. JOURNAL OF PLANKTON RESEARCH VOLUME 24 NUMBER 1 PAGES 69-75 2002

4. Morphology and Phylogenetic Position of an Unusual
   Stentor polymorphus (Ciliophora: Heterotrichea) Without Symbiotic Algae. Noemi M. Fernandes, Inacio Domingos da Silva Neto & Carlos G. Schrago. Journal of Eukaryotic Microbiology 2014, 61, 305–312

5. Stentor. Wilhelm Foissner. ENCYCLOPEDIA OF LIFE SCIENCES 2002 Macmillan Publishers Ltd, Nature Publishing Group. p 561

Video (conjugation): https://youtu.be/314wudMF2qU

Photos are snapshots of the same individual(s) in the video.

Cell size: see scale bar (photos #5-#7)

Site of collection: Pavilion, Takamori Ryokuchi (a freshwater habitat), Sendai, Japan

Date of collection: October 16th 2021

Weather: Rainy

Water temp.: 18.1°C

pH 6.3

Date of observation: October 24th 2021 (the collected sample in a plastic container was left near a window out of direct sunlight at room temperature until observation)

Bright field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan). The accuracy of the scale bar, which was set according to the guidance of the manual of the software (Spectman) provided for the camera, was confirmed by using a stage micrometer glass slide (1 div. = 10 µm; Wraymer, Osaka, Japan) at each magnification.

Video (Cell division): https://youtu.be/3E5zGCVVaLM

Photos are snapshots of the same individual(s) in the video

Cell size: see scale bar (photo #2)

Site of collection: Pavilion, Takamori Ryokuchi (a freshwater habitat), Sendai, Japan

Date of collection: October 16th 2021

Weather: Rainy

Water temp.: 18.1°C

pH 6.3

Date of observation: October 24th 2021 (the collected sample in a plastic container was left near a window out of direct sunlight at room temperature until observation)

Bright field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan). The accuracy of the scale bar, which was set according to the guidance of the manual of the software (Spectman) provided for the camera, was confirmed by using a stage micrometer glass slide (1 div. = 10 µm; Wraymer, Osaka, Japan) at each magnification.

Mag. 200x

• A water sample taken on 03/31/2024, from a small vernal stream in a wooded area, using a small sample bottled attached to an extension pole. Air temp 46F.

Two daughter cells, still attached, of a Closterium sp,. More robustly proportioned than C. kuetzingii (fatter, but with similarly tapering and gently curved apices), a diagnosis of Closterium rostratum seems clear, as seen here http://www.digicodes.info/Closterium_rostratum.html. In the 2nd image, "N" marks the nuclear region (which will eventually become centrally located as each daughter cell matures). Also marked are the 2 chloroplasts normally found in Closterium (one per semi-cell on each side of the nuclear region). I could not find an image of a dividing C. rostratum, but a dividing C. venus, as seen here, https://www.photomacrography.net/forum/viewtopic.php?t=25375, serves as a model.

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/

From a meltwater pond on a grassy trail. Length 35 microns. Two unequal flagella, no visible ingestion tools. The second and third gifs show its attempt to ingest a diatom, without success. When I came back later, a large diatom had successfully been consumed (2nd jpg and 4th gif).

Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 from a biofilm that formed on a sample from the fine sand sulfidic intertidal benthos of marine estuary Acabonac Harbor at Landing Lane. Imaged in Nomarski DIC on Olympus BH2S using SPLANAPO 40 0.90 objective and SPLAN 100 1.25 oil objective plus variable phone camera cropping on Samsung Galaxy S9+. The cell measures 50 um in length, larger than the reported range but it is well known that size varies among populations. Nonetheless, all of the other characters seen as well as the infraciliature matches the redescription of Pan et al 2011 below. It is thought that "Brooklynella, Trochilioides and Microxysma represent transitional genera between Hartmannulidae and Dysteriidae with intellectual morphological characteristics" (2).

"Genus Trochilioides Chen et al. 2011 Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 (Fig. 2; Table 1) According to Article 13.3.3 of ICZN (1999), Trochilioides Kahl, 1931 is a nomen nudum, so Chen et al. (2011) re-established the genus by fixing T. recta as type species. Trochilioides tenuis was originally reported by Deroux (1976c), based only on its infraciliature. So far no re-description has been attempted, we here redescribe it based on a Qingdao population. Improved diagnosis: Small Trochilioides, 30–40 × 20–35 μm in vivo, body elliptical in outline; consistently three right kineties, four left kineties and seven postoral kineties; single contractile vacuole located at anterior of right side; marine habitat" (1).

"Description of Qingdao population: Cell size about 30–40 × 20–35 μm in vivo; body usually elliptical in outline with anterior end bluntly rounded and posterior end somewhat tapered. Ventral side flat and dorsal side humped with several longitudinal stripes after protargol impregnation. Usually, rice-like pellicular granules irregularly distributed on dorsal side. Cytostome prominent, oval shaped, ventrally positioned in anterior 1/5 of cell but nematodesmal rods not detected. Cytoplasm colourless, containing numerous small, greasily shinning globules (2–3 μm across), and food vacuoles (4–8 μm across), which render cells slightly greyish. Single contractile vacuole, about 5 μm in diameter, located at anterior 1/3 of right side. Single oval macronucleus centrally positioned, about 11 × 6 μm in vivo. Podite leaf shaped and 5 μm long, subcaudally located. Cilia 7 μm long. Movement by gliding on the substrate" (1).

"Infraciliature: Consistently, three right kineties, seven postoral kineties and four left kineties surrounding the cytostome. Two right-most kineties almost equal in length, extending anteriorly to anterior margin. Posterior ends of right kineties terminating at the same level and a fragment, comprising three or four basal bodies, located on the left of them. Left and postoral kineties very short, the posterior ends of which are progressively shortened from right to left. Equatorial fragment composed of 0–8 basal bodies, and terminal fragment consisting of 2–4 ones. The oral ciliature composed of three dikinetid fragments: two circumoral kineties (Co) arranged in parallel, equal in length; and one preoral kinety, relatively long, obliquely arranged in front of Co. During cell division, the oral primordium of opisthe generated from three sections of postoral kineties" (1).

1. Taxonomic Studies on Three Marine Ciliates from China, Including a New Species (Ciliophora, Cyrtophorida). Hongbo PAN, Honggang MA, Xiaozhong HU, Khaled A. S. AL-RASHEID and Saleh A. AL-FARRAJ. Acta Protozool. (2013) 52: 25–33 http://www.eko.uj.edu.pl/ap ACTA doi:10.4467/16890027AP.13.003.0831
2. Historical Review of Studies on Cyrtophorian Ciliates (Ciliophora, Cyrtophoria) from China. Zhishuai Qu, Hongbo Pan, Jun Gong, Congcong Wang, Sabine Filker and Xiaozhong Hu. Microorganisms 2022, 10, 1325. https://doi.org/10.3390/microorganisms10071325

Dinobryon from the freshwater acidic kettle pond Chatfield's Hole situated in a white pine forest. Imaged in Normarski DIC using Olympus BH2S under SPlanapo 40 0.90 objective plus variable phone cropping on Samsung S9+. The lorica measures 38 um in length and the cell measures 16 um.

Dinobryon is a type of microscopic algae. It is one of the 22 genera in the family Dinobryaceae. Dinobryon are mixotrophs, capable of obtaining energy and carbon through photosynthesis and phagotrophy of bacteria. The genus comprises at least 37 described species. The best-known species are D. cylindricum and D. divergens, which come to the attention of humans annually due to transient blooms in the photic zone of temperate lakes and ponds. Such blooms may produce volatile organic compounds (VOCs) that produce odors and affect water quality. Dinobryon can exist as free-living, solitary cells or in branching colonies. Though most commonly found in freshwater lakes and ponds, Dinobryon have also been documented flourishing in lotic and estuarine habitats.

Large blooms of Dinobryon are documented most commonly in oligo- to meso- trophic temperate lakes and ponds, though they have also been observed in eutrophic waters. Such blooms regularly occur during springtime at the onset of thermal stratification, and commonly occur following a diatom bloom. The blooms are initiated from resting siliceous spores called statospores that lay dormant on the lake bottom through the winter. Increased spring insolation causes them to germinate, producing amoeboid cells that generate two flagella and encase themselves in a vase-like cellulosic lorica. These motile cells rise into photic waters where they proliferate.

Dinobryon Ehrenberg
Solitary or colonial; individuals with vase-like, hyaline, but sometimes, yellowish cellulose test, drawn out at its base; elongated and attached to the base of test with its attenuated posterior tip; 1-2 lateral chromatophores; usually with a stigma; asexual reproduction by binary fission; one of the daughter individuals leaving test as a swarmer, to form a new one; in colonial forms daughter individuals remain attached to the inner margin of aperture of parent test and there secrete new tests; encystment common; the spherical cysts possess a short process; fresh water.

Dinobryon Ehrenberg, 1834; 34 of 169 species descriptions are currently accepted taxonomically (Guiry and Guiry 2014).
Order Chromulinales; Family Dinobryaceae
Biflagellate heterokont (two differing flagella) cells within a cellulosic lorica of varying length and shape of basal (caudal) spine. Each cell has a prominent stigma (eyespot). The length of the basal (caudal) spine of the lorica is inversely related to water temperature, at least in D. suecicum and D. Borgei (Hilliard 1968).

Dinobryon spp. are planktonic protists that typically form large colonies and are abundant in oligotrophic lakes. Nutrition is by both photosynthesis and phagotrophy (Unrein, 2010). Iron uptake is light dependent; incubation in the dark led to a decrease in iron levels (Carmel, et al., 2014).
Freshwater lakes. Compete well in low-phosphorus lakes in ice-free seasons, and eutrophic phosphorus-rich lakes under ice.

On limestone rock on the trail. Blue prothallus, black thallus heavily isidiate. Tiny lecideine apothecia. Blue-grey-green epihymenium, brown hypothecium. Spores 2-celled, ellipsoidal, 10-12 x 4-6 µm. Secondary phycobiont was Trentepohlia.

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).

My first attempt at diatoms cleaning.

Three specimens observed, from the same sample of my previous observation https://www.inaturalist.org/observations/141202070 taken on 2022-11-05.

Stria density: 7-8 per 10 μm (center), 10-11 (extremities).
Puncta density: 11 per 10 μm.
Length 213-225 µm, width 41-44 µm.

Stigmata visible near the central nodule.

According to Diatoms of Europe vol.3 by Kurt Krammer, 2002, it looks like Cymbella peraspera:
“Valves moderately to distinctly dorsiventral, dorsal margin rather evenly arched, ventral margin with a slightly gibbous central portion. Valve ends not protracted and broadly rounded. Length (130)154-320 µm, breadth 44-52 µm, maximal length/breadth ratio about 6. Axial area moderately wide, linear, widening at mid-valve to form a shallow central area, about ¼ to nearly ⅓ of the valve breadth. Raphe slightly lateral, tape ring near proximal and distal ends, becoming filiform near the proximal and the distal ends. Proximal raphe ends with moderately large roundish central pores which are slightly ventrally deflected; terminal fissures sickle-shaped and dorsally bent. Striae throughout radiate. Puncta distinctly and more or less roundish in focus high and low. A large number of stigmata on the ventral side of the central nodule, in focus low differently shaped from the puncta, commonly distant from the middle ventral striae. Striae 5-8/10 µm, becoming up to 10/10 µm near the extremities. Puncta 7-10(11) in 10 µm.”

Aspidisca leptapsis Fresenius, 1865 from the coarse sand sulfidic intertidal benthos of marine estuary Acabonac Harbor at Louse Point launching ramp. Imaged in Nomarski DIC on Olympus BH2 using SPlan 40x objective plus variable phone camera cropping on Samsung Galaxy S9+.

The cells measure from 66-80 um in length. There are four dorsal ribs on the rigid pellicle. There is a prominent left peristomial spur adjacent to the posterior AZM and a smaller left lateral anterior spur. The posterior cell margin shows 3 or 4 subtle serrations or spurs. There are six transverse cirri with the rightmost one being split into two at the base. There are seven strong fronto-ventral cirri and a single weak one. These characters are congruent with the description of the species by Song and Wilbert (1).

From Song and Wilbert 1997:
"Size of our populations in vivo about 60-80x40-50 um, body elliptical with snout-shaped anterior end; broadest in or behind mid-body, right margin convex, left almost straight, anteriorly broadly rounded; dorso-ventrally highly flattened (ca. 1:2.5-3). Outline associated with indentation or protrusion of cell, one lateral spur subapically located, which is usually smaller than prostomial one even inconspicuous in some specimens. Additionally, several (4-6) posterior spurs on border of caudal portion, which make the cell usually rugged (q.v. Borror 1968; Dragesco 1960; Kahl 1932; Tuffrau 1964). Ventral surface generally flattened, on dorsal always 4 dominant ridges. Buccal area with 1 distinct thorn-like projection (prostomial spur) on left subcaudally, which covers the AZM2. Pellicle rigid. Cytoplasm hyaline. Contractile vacuole right of median, at level of adoral zone of membranelles. Macronucleus C-shaped, with many spherical nucleoli (ca. 1-2 um). Micronuclei several in number (usually 3-5), always located in depressions of macronucleus. Movement crawling on substrate, quite fast compared with other congeners. When disturbed, always attached to substrate firmly for quite a while. Ciliary pattern stable. Frontoventral cirri rather stiff and strong, cilia of 7 large ones about 12-15 um long; one small, satellite-like cirrus close to right-most (posteriormost) cirrus, which is easy to be overlooked (q.v. Agamaliev 1967). Transverse cirri usually strong, tightly arranged in oblique row, base of right-most cirrus always splitting (but mostly imperfectly) into closely spaced 2-3 ones or even more, which are in vivo clearly recognizable. Cilia of transverse cirri about 15-20 um long. Anterior portion of adoral zone (AZM1) containing 7-8 membranelles, located in deep concave. Posterior part (AZM2) significantly long, as usual beneath lid-like prostomial spur. Paroral membrane (PM) small, difficult to observe. Pharyngeal fibres curved anteriorly. Constant 4 dorsal kineties with tightly spaced basal body pairs. Very characteristically, both basal bodies ciliated with rossete-shaped granules at bases of cilia. Each kinety along dorsal ridge and generally extending from end to end of cell (yet 2 central rows may be slightly shortened at posterior end)" (1).

"As we observed both from newly collected samples and in culture, the dorsal ridges and spurs in caudal region, which form the rugged body outline, could vary from less to very conspicuous. Since those characters are so variable and depend so much on description of the observers, we appraise these as weak characters for species separation. Alike is the number of transverse cirri: since the left-most one is only partly divided (the bases are closely connected), the number of those cirri might depend in a large scale on the quality of impregnation. Due to these factors, we suggest that forms with 5-8 transverse cirri, with or without appearance rugged body outline but similar in all other morphological (in vivo and at infraciliature level), biological (habitat, behaviour) and morphometric features should be considered as the same species. Based on the reasons stated above, we synonymize with Aspidisca leptaspis the following species (see; Syn) simply because they show basically no differences but the number of transverse cirri and "absence" of spurs at caudal end of cell" (1).

The redescription of A. leptapsis by Li et al (2010) lists the following synonyms laid out by Song and Wilbert (1997): "Aspidisca leptaspis Fresenius, 1865 Syn. A. sedigita Quennerstedt, 1867; A. crenata Fabre-Domergue, 1885; A. sedigita sensu Dragesco, 1960; A. lyncaster sensu Tuffrau, 1964; A. baltica sensu Borror, 1968; A. psammobiotica Burkovsky, 1970; A. lyncaster sensu Fleury et al., 1968". They depict the subtle posterior serrations (also called spines- see figure from their paper included here) (2).

1. Morphological Investigations on Some Free Living Ciliates (Protozoa, Ciliophora) from China Sea with Description of a New Hypotrichous Genus, Hemigastrostyla nov. gen. Weibo Song, Norbert Wilbert. Archiv für Protistenkunde Volume 148, Issue 4, December 1997, Pages 413-444
2. Morphological Redescriptions of Aspidisca magna Kahl, 1932 and A. leptaspis Fresenius, 1865 (Ciliophora, Euplotida), with Notes on Ontogenesis in A. magna. Liqiong LI, Qianqian ZHANG, Khaled A. S. AL-RASHEID, Choon Bong KWON, Mann Kyoon SHIN. Acta Protozool. (2010) 49: 327–337

Aspidisca leptapsis Fresenius, 1865 from the coarse sand sulfidic intertidal benthos of marine estuary Acabonac Harbor at Louse Point launching ramp. Optical sectioning in Nomarski DIC on Olympus BH2 using SPlan 100x oil immersion objective with oiled condenser plus variable phone camera cropping on Samsung Galaxy S9+. This shows the 5 transverse cirri with the leftmost cirrus split into three bundles of cilia, the seven strong frontoventral cirri showing the bundles of cilia and the single posterior weak frontoventral cirrus , the small posterior and left frontal spurs, the large peristomial thorn, the kinetids of the posterior adoral zone of membranelles, and the 4 dorsal ridges.

The cells measure from 66-80 um in length. There are four dorsal ribs on the rigid pellicle. There is a prominent left peristomial spur adjacent to the posterior AZM and a smaller left lateral anterior spur. The posterior cell margin shows 3 or 4 subtle serrations or spurs. There are six transverse cirri with the rightmost one being split into three at the base. There are seven strong fronto-ventral cirri and a single weak one. These characters are congruent with the description of the species by Song and Wilbert (1).

1. Morphological Investigations on Some Free Living Ciliates (Protozoa, Ciliophora) from China Sea with Description of a New Hypotrichous Genus, Hemigastrostyla nov. gen. Weibo Song, Norbert Wilbert. Archiv für Protistenkunde Volume 148, Issue 4, December 1997, Pages 413-444

Video:
https://youtu.be/z-cW9xeqNpI

Cell size: 29 µm in length, 25 µm in width

Site of collection: Sediment, Pavilion, Katsurashima Ryokuchi north pond (a freshwater habitat), Sendai, Japan

Date of collection: April 29th 2021

Weather: Rainy

Water temp.: 15.1°C

pH 6.5

Bright field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan).

Plagiopyla ovata Kahl, 1931 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 intertidal 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. It is imaged in Nomarski DIC using Olympus BH2S under SPlan 100 1.25 oil objective with oiled condenser plus variable phone cropping on Samsung Galaxy S9+.

Several individuals are shown from this extremely well-fed population which range from 80 up to 96 um in length. The cell size and upward curving mid-region of the oral tube with the right side of upper oral lip slightly bulged forming a nose-like structure serve to distinguish the species from its closest congener P. frontata.

"Body size in vivo about 50–85×33–48µm; length to width ratio about 1.5–2.0:1 in vivo and 1.4–1.9:1 in stained specimens. Body rigid, non-contractile, dorsoventrally flattened, obovate, anterior end widely rounded, posterior end more or less narrowed (Figs 3a, d and 4a–c). Single macronucleus, globular to ellipsoidal, centrally located, about 20–30×15–24µm in vivo and 17–29×12–24µm in stained specimens (Figs 3g and 4d, j). Single micronucleus, globular, about 5µm in diameter in vivo and 4µm in diameter after protargol impregnation, closely associated with macronucleus, i.e. located at edge of, or slightly enveloped by, macronucleus (Figs 3g and 4j). Extrusomes slightly curved, 4–8µm long, distributed uniformly in ectoplasm and randomly in endoplasm (Figs 3a, e and 4e); extruded extrusomes slender needle-like (Figs 3e and 4k). Single contractile vacuole located near posterior end of cell, with two distinct pores located behind dense ciliary rows, pores observable in both living and stained specimens (Figs 3a, b, i and 4d, e)" (1).

"Striated band on dorsal side, starting at level of buccal cavity and extending anteriorly a short distance, then turning sharply backwards forming a loop about 7–10µm long, extending posteriorly parallel to somatic kineties, and terminating just below mid-body region (Figs 3b, i and 4f, i, o). Distance from anterior end of cell to beginning of striated band about 25% of cell length. In total, striated band about 34µm long, i.e. approximately half of cell length, consisting of numerous transverse ridges, each 2–3µm wide. Locomotion by swimming while rotating about main body axis, always spiralling to left" (1).

"In total, 56–63 monokinetidal somatic kineties (30–37 on ventral side and 23–30 on dorsal side), kinetids of ventral kineties usually more densely packed than those of dorsal kineties (Figs 3h, i and 4n, o). One or two dense ciliary rows (DC) in posterior region of cell on dorsal side left of cytoproct, about 6–21µm long, composed of 13–22 kinetosomes (for individuals with two DCs, only the left one is counted) (Figs 3b, i and 4o). Somatic cilia 6–10µm long, uniformly and densely distributed on cell surface (Figs 3a, h, i and 4a, n, o). About ten caudal cilia located along left posterior margin of cell, 8–10µm long, straight and oriented in a different direction to somatic cilia (Fig. 3a). Silverlines in irregular-rectangular grid (Figs 3c and 4i)" (1).

"Oral region formed by two lip-like structures, composed of dense oral kineties. Right side of upper oral lip slightly bulged forming a nose-like structure (Figs 3a and 4h). Slit-like buccal opening located at right-ventral side of cell (Figs 3a, h and 4a). Distance from anterior end of cell to beginning of buccal opening about 25% of cell length (Figs 3a and 4a–c). Tube-like buccal cavity about 85% of cell width, extending transversely to left and curving upwards in mid-region (Figs 3a, f and 4a–d, h). Distance from anterior end of cell to top of buccal cavity about 6–9µm. Oral ciliature more dense than somatic ciliature (Figs 3h and 4n). 53–61 oral kineties on cell surface and extending inwards (Figs 3f, g and 4m, n). Upper oral lip kineties 2–4µm long. Gap between upper oral lip kineties and somatic kineties about 2–3µm (Figs 3a, h and 4g, l, n)": (1).

"The genus Plagiopyla includes nine marine species viz., Plagiopyla binucleata Agamaliev, 1978, Plagiopyla cucullio (Quennerstedt, 1867) Wallengren, 1918, P. frontata Kahl, 1931, Plagiopyla marina Gourret & Roeser, 1886, Plagiopyla minuta Powers, 1933, P. mystax (Lynch, 1930) Nitla et al., 2019, Plagiopyla nyctotherus Poljansky & Golikova, 1959, P. ovata Kahl, 1931, and Plagiopyla stenostoma Alekperov & Asadullayeva, 1996. Among these, P. minuta, P. nyctotherus, and P. mystax are endocommensals of the sea urchin Strongylocentrotus, whereas other species are free-living. Most species of the genus Plagiopyla (including P. ovata) have a single ovoidal to ellipsoidal macronucleus and a single spherical micronucleus. However, two of the known marine species have different nuclear characteristics, i.e. two macronuclei in P. binucleata, and one vermiform macronucleus in P. stenostoma, and thus can be easily distinguished from their congeners" (1).

"P. frontata differs from P. ovata in having a shorter frontal region section (region between anterior cell margin and upper oral lip) relative to the length of the cell (17% in P. frontata vs. 25% in P. ovata), a straight buccal cavity tube (vs. a buccal tube curving upwards in its mid-region in P. ovata), and the upper oral lip perpendicular to the buccal opening (vs. not perpendicular in P. ovata). P. marina differs from P. ovata in having a shorter frontal region relative to the length of the cell (17–20% in P. marina vs. 25% in P. ovata) and long ovoid (vs. ovate to obovate) body shape" (1). P. ovata is smaller than P. frontata. Nitla et al. 2019 emphasized the size range reported by Kahl of P. frontata versus P. ovata 113–174 um vs 73–79 um (2).

1. Redescription and SSU rRNA gene-based phylogeny of an anaerobic ciliate, Plagiopyla ovata Kahl, 1931 (Ciliophora, Plagiopylea). Ran Li, Wenbao Zhuang, Congcong Wang, Hamed El-Serehy, Saleh A. Al-Farraj , Alan Warren and Xiaozhong Hu. Int. J. Syst. Evol. Microbiol. 2021;71:004936 DOI 10.1099/ijsem.0.004936
2. Critical revision of the family Plagiopylidae (Ciliophora: Plagiopylea), including the description of two novel species, Plagiopyla ramani and Plagiopyla narasimhamurtii, and redescription of Plagiopyla nasuta Stein, 1860 from India VENKATAMAHESH NITLA, VALENTINA SERRA, SERGEI I. FOKIN, LETIZIA MODEO, FRANCO VERNI, BHAGAVATULA VENKATA SANDEEP, CHAGANTI KALAVATI and GIULIO PETRONI. Zoological Journal of the Linnean Society, 2019, 186, 1–45.

Metopus gibbus KAHL, 1927 from an ephemeral rainwater puddle in 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+. The cells measure 50-55 um in length and are roughly obconical in shape. The dome protrudes over the posterior end of the cell. The posterior end is rounded. The adoral zone of membranelles extends to roughly 45% of the cell length. The population shows some variation, particularly when cells are distressed when approaching the edge of the coverglass or are about to die they slightly elongate and the posterior half becomes wrinkled or collapsed. All cells feature a tuft of elongated caudal cilia roughly 1/3 the cell length. They seem rather robust and might be syncilia. In addition, there is a tuft of possible syncilia at the anterior dome. There is a terminal contractile vacuole. The macronucleus in all cases is an elongate reniform to sausage-shaped body and shows two distinct orientations-transversely situated in the dome as reported by Foissner et al 2002; other individuals have a longitudinally oriented elongate macronucleus sometimes reaching the level of the contractile vacuole. The macronucleus sometimes appears to be coated with rod-shaped endosymbionts. The bacterial coat of the macronucleus tends to obscure visualization of the numerous nucleoli as described by Foissner et al 2002. A spherical micronucleus is often visible which is always situated in the dome.

The cells swim rapidly rotating about the long axis and they seldom stop. Thus they were very difficult to image. In some fortuitous screen captures I believe I have demonstrated a perizonal stripe having 5 ciliary rows thus ruling out Apometopida. The two different orientations of the macronucleus is of uncertain significance- ie is this two different species or just intraspecies variation in this population. I believe the differences in body shape are due to distress of the cell since I have observed individual cells undergo this change when they approached the edge of the coverglass. Based on the size, macronuclear shape and location, caudal and dome syncilia, I believe this is Metopus gibbus. Dr. Martin Kreutz has reviewed the images and agrees with this assessment.

Redescription: Size 30-55 x 18-35 um in vivo, as calculated from measurements of live specimens and assuming a shrinkage of 10-20% due to the preparation procedures; average values of populations rather close (30-39 x 1847 um). Average length:width ratio (1.5-1.7:1) and ratio of preoral:postoral body portion (1.3-1.8:1) very similar among populations, extreme values, however, rather wide (1.3-1.9:1;1.0-2.4:1). Overall shape pynform to ellipsoidal, dorsoventrally flaffened up to 2:1. Preoral dome conspicuous because occupying about 1/3 of body length in ventral view, projects slightly above ventral and left lateral surface, traverses ventral side almost perpendicularly and merges smoothly into right dorsal surface near posterior third of cell; central dome portion hemispherical, broadly sigmoidal in top view due to curved and slightly bulged dome margin, which forms obtuse angle with ventral surface and merges into anterior left margin of dorsal side. Postoral body portion slightly obconical to cylindroidal with rear end bluntly pointed to evenly rounded. Macronucleus invariably in anterior body half, usually in preoral dome, reniform, rarely ellipsoidal, about 20-25 x 8 um in vivo, becomes stouter (shrinks) under cover glass pressure and in prepared cells; contains numerous nucleoli and is frequently infested by bacteria in Brazllian specimens. Micronucleus usually near or attached to ventral anterior end of macronucleus, about 6 x 4 um in vivo. Cytopyge subterminal on ventral side, slit-like, likely also serving as discharge device for the contractile vacuole because no excretory pore could be found. Cortical granules, possibly mucocysts, about 0.5-1 x 0.4 um in vivo, colourless but highly refractive, orientated perpendicularly to cell surface and closely spaced in about 10-20 rows between each two kineties; stain reddish with methyl green-pyronin and black with silver carbonate, but are not extruded. Cytoplasm colourless to slightly yellowish, contains lipid droplets about 1 um across mainly in preoral dome and numerous, about 5 x 0.5 um-sized, rod-shaped bacteria; no specific granule accumulation in preoral dome. Food vacuoles about 5-10 um across, contain residues of bacteria and their spores. Swims rather rapidly and slightly swaying.

About 25 um long syncilia in anterior region of dome kinety and 30-35 um long synciliary caudal cilia at posterior end of 5-7 dorsal kineties. Perizonal ciliary stripe commences at left margin of dorsal side, follows curvature of bulged ventral dome margin and terminates on right margin of dorsal side in last third of cell; about 4 um wide, composed of five very closely spaced kineties", of which kineties 4 and 5 are often slightly shortened anteriorly and posteriorly and slightly apart from and more widely spaced than kineties 1-3. Adoral zone of membranelles slightly sigmoidal, extends in flat, broad corner formed by preoral dome and ventral surface, commences at left side and extends obliquely to right body margin, performs slight clockwise rotation on plunging into very shallow buccal cavity slightly below mid-body. Paroral membrane in corner formed by preoral dome and ventral surface, commences near midline of cell and curves to proximal end of buccal vertex.

FOISSNER W., AGATHA S. & BERGER H. (2002): Soil ciliates (Protozoa, Ciliophora) from Namibia (Southwest Africa), with emphasis on two contrasting environments, the Etosha region and the Namib Desert. – Denisia, 5: 1–1459.

Peranema trichophorum (Ehrenberg, 1832) Stein, 1878 from the northernmost saprobic edge benthos of the spring-fed freshwater coastal pond at Ocean Dunes Apartments in the Atlantic Double Dunes Reserve. The sampling site is located 250 meters from the edge of the Atlantic Ocean. Imaged in Nomarski DIC on Olympus BH2S using SPlan 40x objective plus variable phone camera cropping on Samsung Galaxy S9+.

The cell measures 75 um when fully extended. There are pellicular striations which are poorly visible. I believe that there are scattered pellicular extrusomes which are not arrayed along the pellicular striations-this character can be highly variable (see discussion below). Two flagella are present. The ingestion apparatus composed of two rods fused by an anterior arc of refractile material is plainly seen. The macronucleus with its large lobed nucleolus is displaced anteriorly by the abundant digesting food in the posterior. This individual has a dimpled posterior.

"Peranema trichophorum (Ehrenberg, 1832) Stein, 1878 Gliding metabolic euglenid, with elongate body measuring 45-65 µm, mostly 55-60 µm long. Body narrowed anteriorly, broadened posteriorly (width up to 1/3 of cell length) where it may be rounded dimpled. Anterior flagellum very thick, about as long or slightly longer than the cell, emerging apically, but arising in a sub-apical flagellar pocket with an associated contractile vacuole. Flagellum beats with flailing motion or is extended in front of the cell while gliding. Flagellar pocket opens with a short slit running along ventral surface, and posterior flagellum emerges from this slit and extends almost the full length of the cell lying in a ventral groove. Body with fine grooves spaced about 1 µm apart. With two ingestion rods measuring to about 1/4 the length of the cell and opening near the posterior end of the slit of the flagellar pocket. The rods appear hollow, are thickened at their most anterior margin and are linked by an anterior arc of refractile material. Cells eat diatoms, other algae and detritus. The nucleus is located in the posterior part of the body and has a lobed nucleolus. The cells may have refractile rod-shaped structures presumed to be extrusomes oriented more-or-less along the long axis of the body in more-or-less complete rows. They appear to be attached to inner surfaces of pellicular folds. Sometimes there is a densely packed collar of extrusomes underlying the cell surface in the region of the flagellar pocket. Some cells were observed with few extrusomes, but they were otherwise similar to isolates with many extrusomes. With variable quantities of refractile (paramylon?) granules. Remarks: This species has been reported from marine and freshwater sites world-wide with lengths from 22 to 81 µm" (1).

"Peranema trichophorum (Ehrenberg. 1832) Stein 1878. Description: Gliding. metabolic euglenid. 30-110 um, mostly 50-75 um long and 8-20 um wide. Cell cylindrical. apically narrowed. The posterior end of the cell is sac-shaped and may have a short point. Cells contain many refractile paramylon grains. The pellicle has delicate, longitudinal ridges with small rod-like bodies (extrusomes). The cell is very metabolic. The anterior flagellum is strongly developed and is about the same length as the cell. The recurrent flagellum is hard to see. It lies in a flagellar canal. which defines the ventral surface of the cell and is 0.75-0.95 of cell length. The ingestion apparatus is well developed, with two rods. The reservoir is located in the first sixth of cell on the right side with an associated contractile vacuole. A spherical nucleus is located in the posterior of the cell. This species eats algae and detritus and two cells observed contained 5-8 other euglenids (Trachelomonas) in food vacuoles" (2).

"Remarks: We regard P trichophorum (basionym Trachelius trichophorus) as the type of this genus. The nature of the type species and the distinctions between it and some other species such as P sacculus. P inflexum. P. cuneatum and P. caudatum have not been clear previously. The type species was originally described with a single flagellum but a second flagellum has been reported by a number of workers (Chen. 1950: Leedale. 1967: Larsen. 1987: Larsen & Patterson. 1990: Ekebom et al., 1996: Lee & Patterson. 2000). The status of other peranemids in which only one flagellum has been reported was unclear, with the presumption that the second flagellum had been overlooked. Lee et al. (1999) confirmed the existence of species with one flagellum, which were then assigned to Jenningsia. This act removed many species (such as P. fusiforme. P mecrostoma as well as a number of species which may have been under-described) from the genus Peremema. The genus now contains two groups: (1) species with a recurrent flagellum lying in a groove and extending almost the whole length of the body and including P. trichophorum. P. pleururum. and P inflexum: and (2) P dolichonema. distinguished because the flagellum trails behind the cell" (2).

"Peranema trichophorum has been reported with lengths from 22 to 81 pm (Huber-Pestalozzi. 1955), as a taxon with or without extrusomes, and as a taxon with or without a pointed posterior end. We have found variation with extrusomes, posterior end, and storage materials in populations of this species. There is considerable overlap with other species assigned to the genus (P pleururum, P inflexum) such that it is probable that descriptions of more than one species have been included under the name P. trichophorum. In an attempt to establish an identity for this species we have compared our organism with Peranema trichophorum 1260/1b from the Culture Collection for Algae and Protozoa (CCAP. The Ferry House. Ambleside. Cumbria LA22 OLP, England). We re-established new cultures from clonal isolates of 1260/lb and cells in these varied in size from 45 to 80µm. but mostly were 55-65 pm. The clonal isolates initially lacked extrusomes. but extrusomes became numerous as populations aged. The CCAP strain and the individuals reported here as P trichophorum have a similar aspect. similar variation in paramylon granules. extrusomes and profile of the posterior end. For the purposes of this paper. we regard this strain and the organisms described above as being of Peranema trichophorum" (2).

"Peranema trichophorum may be difficult to distinguish from some other species of Peranema. There is considerable overlap in size between P. triehopharum and P pleururum or P inflexum. The appearance of the cytoplasm of all of these species can vary because of variable amounts of food vacuoles or paramylon inclusions. In mixed populations, cell length, the longitudinal alignment of extrusomes and the dense collection of extrusomes located subapically (the neck). the relatively wide body and often rounded posterior end of the cell — when used together — are useful in distinguishing this species. We distinguish P. trichapharum from P inflexum Skuja, 1939 because P inflexum is smaller, usually has a more curved body, a pointed posterior end and no extrusomes: and from P pleururum Skuja 1948 which typically has a flattened body, a long pointed posterior end, well marked pellicular ridges and no extrusomes" (2).

1. Free-living Heterotrophic Flagellates from Freshwater Sites in Tasmania (Australia), a Field Survey Won J. LEE, Alastair G. B. SIMPSON and David J. PATTERSON. Acta Protozool. (2005) 44: 321 - 350
2. Schroeckh S., Lee W. J., Patterson D. J. (2003) Free-living heterotrophic flagellates from freshwater sites in mainland Australia. Hydrobiologia 494: 131-166

Video: https://youtu.be/tp6mcazB2rs

Photos are snapshots of the same individuals in the video

Size: see scale bar (photo #2)

Site of collection: Pavilion, Katsurashima Ryokuchi north pond (a freshwater habitat), Sendai, Japan

Date of collection: December 18th 2021

Weather: Snow

Water temp.: 6.6°C

pH 6.5

Date of observation: December 18th 2021 (the collected sample was left at room temperature until observation)

Bright field observation using a Wraymer microscope (model BX-3500TL, Osaka, Japan) equipped with a Floyd-2 HDMI ethernet digital camera (Wraymer, Osaka, Japan).