Supplemental description of Nyctotheroides pyriformis n. comb. (=Macrocytopharynxa pyriformis (Nie, 1932) Li et al. 2002) from frog hosts with consideration of the validity of the genus Macrocytopharynxa (Armophorea, Clevelandellida)

The morphological revisions of Macrocytopharynxa pyriformis (Nie, 1932) Li et al., 2002; collected from the rectum of Fejervarya limnocharis (=Rana limnocharis), are presented in this paper: (1) two surfaces of the organism are not identical - left side narrower and convex, right broader and flat or slightly concave; (2) infundibulum is large and well-developed with no "fold" or "plicature" present in the middle or posterior portion; (3) micronucleus is tiny and ovoid shaped and always embedded in the middle concavity of macronucleus, which can be well revealed by ammoniacal silver staining. Our phylogenetic analysis based on SSU-rDNA showed that M. pyriformis fell into the Nyctotheroides clade, within which four definite Nyctotheroides species were involved - N. cordiformis, N. deslierresae, N. parvus and N. hubeiensis. In combination with their morphological features, we discussed the reliability of using karyophore organelles or kinetal suture patterns as the generic taxonomic criteria. Besides, we considered that the genus Macrocytopharynxa is a junior synonym of Nyctotheroides and we transfer its type species to Nyctotheroides as Nyctotheroides pyriformis n. comb. The phylogenetic pattern of the family Nyctotheridae was also indicated in our work, but it will be necessary to analyze more species from fishes and reptiles before coming to a sound conclusion.

Morphology of Nyctotheroides hubeiensis Li et al. 1998 from Frog Hosts with Molecular Phylogenetic Study of Clevelandellid Ciliates (Armophorea, Clevelandellida)

The morphology of Nyctotheroides hubeiensis (Acta Hydrobiol. Sin. 1998, 22(suppl.):187), collected from the rectum of Phelophylax nigromaculatus, is presented in this paper based on detailed morphological information and molecular data. Our phylogenetic analysis showed that N. hubeiensis fell into the Nyctotheroides clade, which was strongly supported as monophyletic and clustered as basal to the genera Nyctotherus and Clevelandella. Also, the monophyly of the Order Clevelandellida and the affinity of parasitic nyctotherids and free-living metopids were indicated in our work. The origin of clevelandellid ciliates as well as their possible evolutionary history was also discussed here; however, the analysis of more species from other vertebrate hosts (fish, reptiles) should be made before a well-supported conclusion can be drawn.

Novel insights into the genetic diversity of Balantidium and Balantidium-like cyst-forming ciliates

Balantidiasis is considered a neglected zoonotic disease with pigs serving as reservoir hosts. However, Balantidium coli has been recorded in many other mammalian species, including primates. Here, we evaluated the genetic diversity of B. coli in non-human primates using two gene markers (SSrDNA and ITS1-5.8SDNA-ITS2). We analyzed 49 isolates of ciliates from fecal samples originating from 11 species of captive and wild primates, domestic pigs and wild boar. The phylogenetic trees were computed using Bayesian inference and Maximum likelihood. Balantidium entozoon from edible frog and Buxtonella sulcata from cattle were included in the analyses as the closest relatives of B. coli, as well as reference sequences of vestibuliferids. The SSrDNA tree showed the same phylogenetic diversification of B. coli at genus level as the tree constructed based on the ITS region. Based on the polymorphism of SSrDNA sequences, the type species of the genus, namely B. entozoon, appeared to be phylogenetically distinct from B. coli. Thus, we propose a new genus Neobalantidium for the homeothermic clade. Moreover, several isolates from both captive and wild primates (excluding great apes) clustered with B. sulcata with high support, suggesting the existence of a new species within this genus. The cysts of Buxtonella and Neobalantidium are morphologically indistinguishable and the presence of Buxtonella-like ciliates in primates opens the question about possible occurrence of these pathogens in humans.

Food vacuole contents in the ciliate, Balantidium jocularum (Balantididae), a symbiont in the intestine of the surgeonfish, Naso tonganus (Acanthuridae)

During the past 16 years, the ciliate Balantidium jocularum has been collected from the intestines of many specimens of its fish host, Naso tonganus, all collected from the Great Barrier Reef near Lizard Island, Australia. Ciliates for this study of food consumption were isolated in 1988, 1989, 2003, and 2005. Nineteen specimens of B. jocularum were examined in the transmission electron microscope to determine the contents of both food vacuoles and a putative discharging cytoproct vacuole. Food vacuoles contained rod-shaped bacteria, tightly coiled spirilliform bacteria, and one or more euglenid flagellates. In several balantidia of somewhat different form than the type species of B. jocularum, the large bacterium, Epulopiscium fishelsoni, was observed in light microscope protargol preparations. Some putative phagolysosomes retained spirilliform bacteria that were apparently intact, and others contained partially digested flagellates. Food in a single discharging cytoproct vacuole consisted of normal appearing spirilliform bacteria, some other bacteria, and no flagellates. The results argue for non-selective ingestion of food and selective digestion; hence, somewhat inefficient food processing.

New species of Balantidium and Paracichlidotherus (Ciliophora) inhabiting the intestines of four surgeonfish species from the Tuvalu Islands, Pacific Ocean

Four species of adult herbivorous surgeonfishes (Family Acanthuridae) were collected from the remote South-Pacific island system of Tuvalu. Their intestinal contents were examined, and of four populations of ciliated protists, two new species were discovered and are described. Ciliates were examined after protargol staining and, in some cases, scanning electron microscopy. Members of each population were examined and 10 characters measured for the balantidia, and 13 for the paracichlidotherids. A new Balantidium is described which has an unusually large dextr-oral field of cilia. A new species of Paracichlidotherus was discovered which has a macronucleus significantly smaller and well anteriad the cytoplasmic portion of the oral polykinetids relative to the type species.

Whorl-like outer segments in the retina of the mole (Scalopus aquaticus)

The retina of the common mole, Scalopus aquaticus, has been studied with the transmission electron microscope. Structures examined include: pigment epithelium, outer and inner segments of the sensory cells, and synaptic ribbons of the outer plexiform layer. Rods and cones described in species by previous light microscopic studies are not seen with electron microscopic techniques. Instead, the mole retina contains peculiar outer segments consisting of whorls of membranes. These whorls have some similarities to dystrophic retinas of several vertebrates. The possibility of their being caused by extraordinary light exposure is discussed, also. The appearance of the sensory cells suggests that they are functional receptors.

The ejectisomes of the flagellate Chilomonas paramecium: visualization by freeze-fracture and isolation techniques

Freeze-fracture procedures were used to visualize ejectisomes and adjacent plasma membrane specializations in the flagellate protozoan Chilomonas paramecium. The ejectisomes are membrane-bounded, cylindrically rolled, extrusive organelles. Small ones occur in large number beneath the plasma membrane of the body and considerably larger ones are located around the gullet membrane. The intra-membrane particle distribution is different in each type. In small ejectisomes, the portion of the membrane in contact with the plasma membrane of the body has a P-face rosette of five particles while the plasma membrane has not been observed with a rosette. Small ejectisomes and plasma membrane both contain aggregations of particles a short distance from the contact or docking site. Slightly beneath the plasma membrane is the periplastic sheet with which we speculate the small ejectisomes interact during the docking phenomenon. No obvious rosettes have been observed in large ejectisomes. Some other ejectisomal structures are presented and discussed.

Subpellicular microtubules of Euplotes eurystomus: their geometry relative to cell form, surface contours and ciliary organelles

There is a layer of microtubules (MT) beneath the innermost pellicular membrane of the ciliated protozoan Euplotes eurystomus. These MT have been revealed for scanning electron microscopic study by chemical dissection techniques. In much of the body of this ciliate, these MT are oriented parallel to its long axis. Those directed towards cirri, which are complex ciliary structures of the ventral surface, either abut or bend around the cirral base. MT adjacent to or closely associated with the ciliary feeding structures (membranelles of the adoral zone of membranelles or AZM) are oriented parallel to the long axis of the AZM. Some of the MT within the oral cavity have quite complex paths. The various orientations of these subpellicular MT are discussed and evaluated for hypothetical functions of cytoskeletal support, cell shaping and organelle movement. Each of these roles is considered to be theoretically possible.

Microtubules beneath the pellicles of two ciliate protozoa as seen with the SEM

Chemical procedures remove some of the outer 3 limiting membranes of 2 ciliate protozoa, Euplotes eurystomus and Tetrahymena pyriformis, and reveal sheets of microtubules in their ectoplasm for SEM study. This greatly enhances the analysis of the 3-dimensional geometry of these sheets, as is shown especially for E. eurystomus. In this organism, sheets of microtubules can readily be observed and described as they course through or around parts of th oral apparatus and other 3-dimensionally complex regions.