Copterus tyloloricatus (Ciliophora, Suctorea), a new suctorian genus and species.

We present the description of the new suctorian genus Copterus gen. n. with type species Copterus tyloloricatus sp. n. from the family Acinetidae, inhabiting the prosomes and urosomes of calanoid copepods from the northern North Pacific Ocean. The new taxon is characterized by (i) an ellipsoidal to triangular, asymmetric, dorsoventrally flattened cell body, which lies horizontally on the lorica surface; (ii) an unflattened lorica; and (iii) the presence of three to five radially arranged bundles of tentacles positioned at the edge of the body or on actinophores.

New find of Dactylophrya-stage of parasitic suctorian of genus Tachyblaston Martin, 1909 (Ciliophora, Suctorea) with comments on genus taxonomy.

The article presents the new find of Dactylophrya-stage of rare parasitic suctorian ciliate of genus Tachyblaston on harpacticoid copepod from Mumbai, India. The found specimen was identified as Tachyblaston reversum (Collin, 1909), n. comb. The redescription of T. reversum was provided. The refined diagnoses of genus Tachyblaston and included species, data on distribution of genus representatives, synonymy and comments on genus taxonomy are also presented.

Epibiontic life on intertidal Setaphyes kielensis and S. dentatus (Kinorhyncha, Pycnophyidae) from Sylt, North Sea, Germany, with a description of a new species of Trematosoma (Ciliophora, Acinetidae) and a redescription of Cothurnia buetschlii (Ciliophora, Vaginicolidae).

Specimens of two species of Kinorhyncha, Setaphyes dentatus and S. kielensis, were collected in 1988, 1998, and 2016 at two intertidal sites on the island of Sylt, North Sea, and investigated as preserved material by light microscopy and scanning electron microscopy for their epibionts. One species of Acinetidae (Suctoria), one species of Vaginicolidae (Peritrichia), and two species of bacteria were traced. The most abundant ciliate species with 705 specimens was Trematosoma husselae sp. nov. occurring with 146 specimens on a basibiont, mainly on the ventral side and here especially on segment 1. Cothurnia buetschlii was found as 14 specimens. Trematosoma husselae sp. nov. agreed with T. amphiasci and T. pusilla in the calyciform shape of the lorica and with most species in the general size of the body except for the much larger T. constricta and T. pusilla. The new species could be distinguished from T. amphiasci, T. complatana, T. constricta, T. falcata, T. ovata, and T. pusilla by the short length of its stalk and agreed with T. bocqueti and T. rotunda in this character. Cothurnia buetschlii was redescribed for the first time after the descriptions by Zelinka (1914, 1928).

Report of suctorian ciliates (Ciliophora, Suctorea) as epibionts on meiobenthic nematodes in an oxygen minimum zone of the Arabian Sea, Indian Ocean.

Three suctorian ciliate species, Paracineta livadiana (Mereschkowsky, 1881), Loricophrya bosporica Sergeeva Dovgal, 2014 and Acinetopsis lynni Baldrighi et al., 2020 are found as epibionts on meiobenthic nematodes in an oxygen minimum zone of the Arabian Sea. All three species are recorded here for the first time from the Indian Ocean.

A checklist of species of Podophryidae (Ciliophora: Suctoria) as Epibionts of Crustaceans.

The epibiotic relationship between crustaceans and ciliates is frequent, for example, with species of suctorians. This work aims to present an updated list of species of the family Podophryidae worldwide distributed as epibionts of crustaceans and its geographic distribution. The available literature was checked, and all the species were verified. We found four species and four species indeterminata attached to 16 species of crustaceans. For the American continent, we obtained four species, and for Africa and Oceania, we did not find any species.

Report of Acineta euchaetae Sewell, 1951 from new locality of the Arabian Sea with notes on their taxonomy and distribution.

The article deals with the data about new find of the rare suctorian species Acineta euchaetae Sewell, 1951 on calanoid copepod host Euchaeta marina (Prestandrea, 1833) from the Arabian Sea. Seven young (sub-adult) individuals of the ciliate were observed on rear part of cephalothorax and on abdomen of adult male of copepod. The data about all known finds of A. euchaetae are discussed as well as the information on different developmental stages of the ciliate species. It is suggested that A. euchaetae is euryhaline species distributed in Eurasian coastal and inland waters and have preference for calanoid copepod hosts, but do not show specificity to any calanoid genus or species. The summarized diagnosis and refined systematic position of A. euchaetae are also provided.

Suctorians (Ciliophora: Suctoria) as epibionts of decapods of families Cambaridae and Pseudothelphusidae.

Epibiosis is common among ciliates and crustaceans because the calcified surface of the crustacean body offers a suitable site for colonization by the epibiont. Suctoria are among the most common epibiont ciliate groups of freshwater decapod crustaceans. The aim of this study is to increase knowledge of suctorians as epibionts of freshwater decapod crustaceans of the families Cambaridae and Pseudothelphusidae. Crustaceans were collected from three rivers and one pond in Chiapas, Mexico. Six species of suctorian epibionts were recorded: Acineta tuberosa, Podophrya maupasi, P. sandi, Tokophrya cyclopum, T. quadripartita and Trichophrya epistylidis. This is the first record of ciliate epibionts on members of family Pseudothelphusidae (represented by Phrygiopilus montebelloensis and Raddaus bocourti), and the first record of suctorians epibionts on Procambarus (Austrocambarus) sp. (Cambaridae).

A hydrothermal vent mite (Halacaridae, Acari) with a new Corynophrya species (Suctoria, Ciliophora), description of the suctorian and its distribution on the halacarid mite.

Copidognathus nautilei Bartsch, 1997, from a hydrothermal vent field of the Mid-Atlantic Ridge at about 13 degrees N, 45 degrees W and 4090 m depth, was infested with the suctorian Corynophrya abyssalis n. sp., with up to 58 epizoans per mite. The new suctorian has a sacciform body with seven longitudinal ribs, a compact macronucleus and up to 40 non-retractile tentacles. The budding is exogenous. The systematic position of the new species and the genus Corynophrya is discussed, as well as infestation rates and sites of suctorians on their halacarid hosts.

Improved preparation and swimming behavior of Triton-extracted models of Didinium nasutum.

An improved method for the preparation of Triton X-100 extracted models of Didinium nasutum was established. Didinium models prepared by treatment with a Triton X-100 solution, containing specific proteolysis inhibitors and dimethyl sulfoxide, maintained an intact shape at 25 degrees C for a longer time than models prepared by treatment with a Triton X-100 solution not containing the proteolysis inhibitors and dimethyl sulfoxide. The improved Didinium models were reactivated so as to swim forward in the presence of Mg2+ and ATP or ADP. They did not swim backward in response to Ca2+, in contrast to well-known Paramecium models. However, the improved Didinium models showed circular swimming and spinning in response to 10(-6) M or higher concentrations of Ca2+. This observation suggests that the quick directional change as well as the spinning, which are characteristic of live Didinium, are due to an increase in the endoplasmic Ca2+ concentration around the ciliary system. The response of the Didinium ciliary system to Ca2+ may differ from the response of the Paramecium ciliary system to Ca2+.

Intracellular calcium transients in suctorian protozoa (Trichophrya spp.): correlation with spontaneous tentacle contractions.

The luminescent photoprotein aequorin was used to measure intracellular free Ca2+ in three species of suctorian protozoon, Trichophrya riederi, Trichophrya collini and Trichophrya rotunda. Resting [Ca2+]i ranged from about 75-110 nM, and was unaffected by a change in temperature of the perfusate. Spontaneous Ca2+ transients were observed in all three species, with peak amplitudes ranging from 100-600 nM. In T. riederi and T. rotunda, three categories of transient (small, intermediate, large) were recorded; T. collini displayed only small transients. In both T. riederi and T. collini, raising the temperature from 5 degrees to 26 degrees C led to an increase in the frequency of transients. Furthermore, in T. riederi, large transients occurred only at the higher temperature. The frequency of spontaneous contractions of the tentacles of T. riederi was also temperature-dependent. Increasing the temperature over the range 5-26 degrees C led to a concomitant increase in contraction frequency and a decrease in mean tentacle length. The possible mechanisms of spontaneous Ca2+ transient generation and their role in the control of contraction are discussed.

Chilodonella spp. at four fish farms in northern Finland.

A total of 4.1% infestation with Chilodonella spp. was found among fish studied in 144 tanks in 1987-1989, representing 14.0% of the tanks in which fish are reared at four salmonid farms in northern Finland. Two species were found, C. hexasticha and C. piscicola, and both occurred on salmon (Salmo salar L.), sea trout [S. trutta m. trutta (L.)] and brown trout [S. t. m. lacustris (L.)]. Variability was observed in the length and width of the C. piscicola specimens and the number of ciliary rows or kineties. Large specimens which had more kineties than average for C. piscicola were found mainly on the skin of salmon aged 1-2 years. The number of kineties in the right ciliary band was found in stepwise logistic regression analysis to be of importance when typing C. piscicola specimens. Fingerlings were found to be more susceptible to Chilodonella infestation than older fish, and mortality varied in the range 2-10% in the course of the epizootics in the three fish species. Most mortality cases were caused by C. hexasticha, occurring mainly on the gills of the fish. Chilodonella piscicola was most often found in salmon and occurred at lower water temperatures than C. hexasticha (mean water temperature when found for the first time being 13 degrees C and 16 degrees C, respectively).

Rumen ciliate protozoa of the blue duiker (Cephalophus monticola), with observations on morphological variation lines within the species Entodinium dubardi.

Protozoal concentrations were determined in rumen and cecal contents of 20 blue duikers (Cephalophus monticola). Ten animals of each sex were fed either a high concentrate or high roughage diet. Rumen protozoa were present in 19 of the 20 animals and concentrations ranged from 4.5 to 33.7 x 10(6) per g of rumen contents. At the higher concentrations, protozoal cells equaled between 30-40% of the total rumen contents volume. No protozoa were found in cecal contents. Weight of rumen contents was higher in females than in males (P < 0.01), and rumen protozoa concentrations were higher in males (P < 0.05) and in those animals fed the high concentrate diet (P < 0.05). All the protozoa were identified as belonging to a single species, Entodinium dubardi. However, an average of about 30% of the E. dubardi cells varied from the typical morphology of this species. These cells appeared to be on variation lines leading toward 7-10 other non-caudate species of Entodinium. The present data were used to evaluate and discuss the concept of variation lines within E. dubardi.

Immunological characterization of trichocyst proteins in the ciliate Pseudomicrothorax dubius.

Ejectable trichocysts were isolated from the ciliate Pseudomicrothorax dubius. Polyclonal antibodies were raised against three groups of trichocyst proteins: G1 (30-31 kDa), G2 (26-27 kDa) and G3 (15-20 kDa). By indirect immunofluorescence, the three antisera strongly label the shafts of ejected trichocysts and the proximal ends of condensed trichocysts within the cells. By immunogold labeling for electron microscopy, the three sera specifically recognize the shafts of both extended and condensed trichocysts and shaft precursors in pretrichocysts as well. On one-dimensional immunoblots of isolated trichocysts, anti-G1 serum recognizes the G1 proteins, anti-G2 serum detects G2 proteins and some G1 proteins, and anti-G3 serum reacts with 15 bands, mainly the G3 and (30-41)-kDa proteins. In cells with and without trichocysts, the sera recognize non-ejectable trichocyst proteins at 41-42 kDa and 47 kDa. On two-dimensional immunoblots of isolated trichocysts, anti-G1 serum labels proteins with a pI of 4.75-5.7, anti-G2 serum labels proteins with a pI of 4.75-6.25 and anti-G3 serum labels proteins with a pI of 4.7-6.6. Analyses of cells with and without trichocysts allow identification of possible precursors between 41 and 47 kDa. Some are in the same pI range as their putative products, but others, labeled by anti-G3 serum, are less acidic than most of their mature products.

Infraciliature, morphogenesis and life cycle of Endosphaera terebrans (Suctoria, Tokophridae).

The morphology, infraciliature, and life cycle of Endosphaera terebrans, a suctorian endocommensal of peritrichs, have been studied with the aid of silver impregnation. The life cycle of Endosphaera terebrans begins with infection of the host cell by a small larva. The swarmer has a pointed needle-like cellular projection and two rings of cilia. The swarmer penetrates the the peritrich, loses the cilia, and then matures into an adult. The infraciliature of the adult form has four rows of barren kinetosomes that lack kinetodesmal fibers. By endogenous budding, a migratory larva is produced that leaves the host cell through the peristomial disc and that can infect other peritrichs.