Vergleichende Untersuchung der Ciliatensukzession beim Abbau von Zellstoff in marinem Brackwasser und athalassogenem Brackwasser vom Typ der Kaliwerksabwässer

Zusammenfassung Die Sukzession der Ciliaten beim Abbau von Zellstoff wurde unter Laboratoriumsbedingungen in marinem Brackwasser und in künstlichem Kaliwerksabwasser verfolgt. Im untersuchten Bereich bis hinauf zu 7 g/l Gesamtsalzgehalt verlief der Zellstoffabbau wie im Süßwasser. Bei Verwendung von Süßwasserorganismen als Impfmaterial zeigte sich mit steigendem Gesamtsalzgehalt eine Verminderung der Artenzahl gegenüber der Süßwasserkontrolle; diese Veränderung war in beiden Versalzungstypen nahezu gleich. Parallel mit der Verarmung des Artenspektrums erfolgt bei mehreren Arten eine deutliche Vermehrung der Individuenzahl in den höheren Salzkonzentrationen.

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Summary The succession of freshwater ciliates associated with the decay of cellulose was investigated in thalassogenic brackish water and in athalassogenic brackish water derived from waste water of potash works. The amount of decomposition of cellulose was the same in both sorts of brackish water (up to 7 g/l salt content) and in freshwater. When brackish water was used instead of freshwater, the number of species of ciliates decreased while the total number of individuals of Cyclidium citrullus, Euplotes affinis and others increased. The changes in the succession of ciliates were nearly the same in both sorts of brackish water.

     

Oenothorachona ectenolaemus n.g., n.sp. and Spirochona halophila n.sp., Two New Marine Chonotrichous Ciliates

SYNOPSIS. Two new species of chonotrichous ciliates, Oenophorachona ectenolaemus n.g., n.sp. and Spirochona halophila n.sp. were found on Anisogammarus sp. collected from the waters of Humboldt County, California and Argyle Bay, San Juan Island, Washington. This is the 1st reported occurrence of 2 genera of chonotrichous ciliates on a single host species as well as the 1st of the occurrence of Spirochona in marine and brackish water environments.     

Untersuchungen zur Verträglichkeit von Meer- und Brackwasser für Ciliaten des Saprobiensystems der Wassergütebeurteilung

Zusammenfassung 1. Die Verträglichkeit von Brack- bzw. Meerwasser für saprophile Süßwasserciliaten wurde in Modellversuchen mit Zellstoffabbau untersucht.2. Repräsentative Sukzessionsdiagramme von ausgewählten Brackwasserkonzentrationen werden mitgeteilt.3. Die Mehrzahl der geprüften Süßwasserciliaten kam nur im Bereich bis 3,5 S vor; mehrere Arten waren aber in der Lage, auch bei hohen Versalzungen zu existieren und erreichten hier sogar hohe Bestandsdichten.4. Auffallend war, daß bei einigen Arten sehr lange Verzögerungsphasen im Populationswachstum auftraten.

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Studies on the toleration of sea and brackish water by ciliates of the saprobic system for evaluating water pollution levels

More than 50% of the indicator organisms of the higher polluted zones are ciliates. Owing to this fact, ciliates are used extensively in laboratory experiments in order to produce more information regarding their ecological tolerances. The present paper reports new results obtained on ciliates exposed to sea and brackish water. The succession of freshwater ciliates associated with the decay of cellulose was investigated in 30-liter basins; detailed information is presented on successions observed in various concentrations of brackish water. When brackish water was used instead of freshwater, the number of ciliate species decreased rapidly, e. g., 40 species were found in freshwater, 26 in 3.5 S, 10 in 14 S and 4 in 35 S, respectively. Only a few indicator organisms used in fieshwater may, therefore, be of real value as indicators in high concentrations of brackish water. Most of the freshwater ciliates tested are not able to tolerate higher salinities at all.

     

Ciliated Protozoan communities in a fluvial ecosystem

The ciliated protozoan communities in the Llobregat River (Barcelona, Spain) were studied for one year. Samples were taken from 11 different stations. The physical-chemical factors of the water as well as the qualitative and quantitative nature of the ciliate populations were considered. 105 species of ciliates, grouped in 13 orders, were found.The species which constantly appeared at all 11 stations (although not every month) were Litonotus fasciola, Trithigmostoma cucullulus, Cyclidium glaucoma, Glaucoma scintillans, Vorticella microstoma, Oxytricha sp., Stylonychia mytilus, Aspidisca costata and Aspidisca lynceus. The index of diversity at the different stations, and the affinity between the most abundant species, were also determined.     

Isolation and identification of herbivorous ciliates from contaminated microalgal cultures

Ciliates are a common but understudied group of grazers that can invade microalgal cultures. To estimate the potential impact of ciliates on microalgal culture productivity, the identification of species that can invade these cultures is essential. Furthermore, isolation of these herbivorous ciliates allows to use them in experiments that investigate the impact of ciliate grazing on the productivity of microalgal cultures. The main aims of this study were to isolate and identify ciliates that invade cultures of the freshwater microalgae Chlorella and Chlamydomonas, and to establish a live collection of these ciliates for usage in future experiments. To this end, we optimized a method for isolating ciliates from contaminated microalgal cultures and we developed a new PCR primer set for amplifying the partial 18S rDNA of ciliates belonging to the classes Spirotrichea, Oligohymenophorea and Colpodea. As a result, we isolated 11 ciliates from microalgal enrichment cultures inoculated with non-sterile dust and various freshwater sources. Of these 11 species, 7 were found to be feeding on Chlamydomonas. Ciliate species that fed on Chlorella could not be isolated in this study. Ciliate species feeding on Chlamydomonas were identified based on a combination of morphological observations and molecular analyses of partial 18S rDNA sequences.     

Molecular Phylogeny and Taxonomy of Two Novel Brackish Water Hypotrich Ciliates,with the Establishment of a New Genus,Antiokeronopsis gen. n. (Ciliophora,Hypotrichia)

Two novel brackish water urostyloid ciliates, Anteholosticha paramanca sp. n. and Antiokeronopsis flava gen. n., sp. n., isolated from the Shenzhen Mangrove Nature Protection Area on the coast of the South China Sea, were investigated using live observation and protargol impregnation techniques. Anteholosticha paramanca sp. n. is characterized by its spherical yellowish cortical granules arranged in lines, shortened midventral complex and three transverse cirri. Morphogenesis is similar to that in Anteholosticha manca. The new genus Antiokeronopsis is diagnosed by having a continuous adoral zone of membranelles, frontal cirri arranged in a bicorona, midventral complex composed of midventral pairs only, one marginal cirral row on each side, the presence of frontoterminal and transverse cirri, and the lack of buccal and caudal cirri. The type species A. flava sp. n. is characterized by its elongated body shape, brown to yellowish body color and two types of cortical granules. Small subunit ribosomal RNA gene sequence data justify the classification of both species. Phylogenetic analyses indicate that A. paramanca clusters with Bakuella subtropica within a clade that includes two other Anteholosticha species, while Antiokeronopsis groups within the core urostylids and is most closely related to the well‐known genera Pseudokeronopsis and Uroleptopsis.     

Distributions and Biomass of Benthic Ciliates,Foraminifera and Amoeboid Protists in Marine,Brackish, and Freshwater Sediments

The quantitative importance of ciliates, foraminifers, and amoebae was investigated in marine, brackish, and freshwater sediments from 15 littoral stations. Total protozoan communities were usually dominated by ciliates in term of abundance, while amoebae often dominated in terms of biomass. Applying the biomass‐metabolic rate equation, ciliates, amoebae, and foraminifera were estimated to contribute 66% of the total abundance and 33% of the biomass, but up to 55% of the combined metabolic rate to the micro‐ and meiobenthos in the 15 sediments. Statistical analyses using ciliate data demonstrated: (1) species composition and community structures represented significant differences between freshwater and marine/brackish sediments, and subsequently between temperate and arctic sampling sites; (2) the occurrence of dominant ciliates and their allocation to feeding types indicated that herbivory was the most common feeding strategy in these sediments; (3) multivariate analyses showed all of the tested environmental factors (temperature, salinity, silt/clay, carbon, nitrogen, and chlorophyll a) to be important to varying degrees, but especially the combination of salinity, temperature, and silt/clay. Multiple factor effects or comprehensive influences might be important in regulating the distribution of protozoa in sediments. The importance of protozoa in sediment systems and the potential ecological significance of cysts are discussed.     

The role of predators in the stable coexistence of several alga species

Experiments were conducted on growing mixed cultures of green Ankistrodesmus arcuatus Korsch and diatom Diatoma elongatum (Lyngb.) algae with and without ciliates Cyclidium glaucoma Ehrenberg and Paramecium caudatum Ehrenberg in accumulative and perfusion cultures. Both alga species successfully developed in the presence of ciliates despite their grazing on both alga species; however, in their absence, Ankistrodesmus arcuatus were suppressed and did not develop. It is supposed that ciliates contribute to the stabilization of the community not only as predators but also by excreting dissolved reduced nitrogen into the environment as a result of their vital functions.     

Planktonic ciliates of the Baltic Sea (a review)

The data on the ciliates species composition are given for the Baltic Sea, a brackish-water semi-closed water body where a considerable part of the planktonic fauna is presented by freshwater species. During the observation period, 789 species of ciliates were found, 160 of which are typical planktonic forms. The ecological characteristics of ciliates are given, along with an assessment of their role in the productivity of the Baltic Sea pelagic communities.     

Experimental Approach to the Role of Protozoa in Aquatic Ecosystems

In enrichment batch experiments, samples from three water bodieswere alternatively supplemented by various amounts of organicmaterial and incubated at 20 C. Colpidium campylum reached itshighest total cell volumes in cultures with the highest initialtotal cell volumes in cultures with the highest initial concentrationsof organics; Cyclidium glaucoma preferred lower concentrations;and Glaucoma chattoni occupied the intermediate position. Noneof the species preferred any special type of organic material.In two-stage continuous-flow units, a mixed culture of bacteriawas kept in stage I and the clones of ciliates were maintainedin stage II. The interrelations between the total cell volumesof ciliates at various concentrations of bactopeptone were inaccordance with the results from the enrichment experiments.Since the growth of bacteria continued in the presence of ciliates,a four-stage apparatus was constructed in which a bacterialculture was raised and diluted in three stages before enteringthe culture ofColpidium. The bacterial growth in the presenceof Colpidium was not eliminated even by this arrangement, asdemonstrated by dosing antibiotics along with bacteria. An effectof ciliate metabolites on bacterial growth rate is suggested,completing a metabolic cycle in the bacteria-protozoa system.     

Global distribution of free-living microbial species

Species of large animals and plants have geographically restricted distributions, but it is unclear if this also applies to free-living micro-organisms. We have attempted to clarify this, by investigating the ciliated protozoa living in a habitat that is separated from northern Europe by geographical barriers and great distance - the sediment of a Holocene volcanic crater-lake with brackish water, in Australia. Of the 85 ciliate species recorded, none was 'new', and all (apart from one species previously described only from tropical Africa) are known from northern Europe. All species appear to have reached the crater by passive dispersal from other freshwater and marine environments. The significance of this finding lies in the fact that ciliates are among the largest and most fragile of microbes. If ciliate species have global distributions, it is likely that the same is true for the many smaller, more abundant and more easily dispersed microbial species, including bacteria. There is some support for this in the literature, and most species smaller than ca 1 mm may have global distributions. Biodiversity at the microbial level is fundamentally different from that of macroscopic animals and plants, and it may be difficult to make realistic extrapolations from the attributes of microbial communities, to biodiversity in general.     

Effects of Glutaraldehyde and Osmium Tetroxide on Hypotrichous Ciliates, and Determination of the Most Satisfactory Fixation Methods for Electron Microscopy

SYNOPSIS. In electron microscope studies on hyppotrichous ciliates, cytolysis and/or body deformation–resulting from insufficient contact with glutaraldehyde and poor infiltration of Epon 812, particularly into the buccal cavity, usually were observed. Fixation experiments were carried out to examine the effects of some fixatives on Euplotes eurystomus, Oxytricha bifaria and Stylonychia mytilus to establish the best fixation technic applicable to all species of hypotrichous ciliates. Although the effects of fixation varied considerably with the species, 2 fully satisfactory fixation methods were developed by using OsO₄ and glutaraldehyde. In one, a mixture of both fixatives was employed; in the other a very short application of OsO₄ was followed by glutaraldehyde. The problem of infiltration was solved by using Spurr's low-viscosity embedding medium in place of Epon 812.     

Redescriptions of Uronema filificum and U. elegans*

SYNOPSIS. Two species of hymenostome ciliates, Uronema filificum, and U. elegans, are described from the Atlantic coast. Studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic, and particular attention was given to the buccal infraciliature.     

Parasite fauna of bream Abramis brama and roach Rutilus rutilus from a man-made waterway and a freshwater habitat in northern Germany

Fifty specimens each of bream Abramis brama and roach Rutilus rutilus were examined for metazoan parasite fauna and trichodinid ciliates; 25 specimens of each species were collected from the Kiel Canal, a man-made waterway, and a nearby freshwater lake, the Dieksee. This is the first detailed parasitological examination of A. brama and R. rutilus at these locations: 30 parasite species were found, comprising 4 protozoans, 4 myxozoans, 5 digeneans, 3 monogeneans, 2 cestodes, 6 nematodes, 2 acanthocephalans, 3 crustaceans and 1 hirudinean. The crustacean Caligus lacustris occurred in both habitats while 2 other crustacean species, 2 acanthocephalans and 1 hirudinean were recorded exclusively for the lake habitat. Larval as well as adult stages of the different parasite species were found, indicating that both fish species act as intermediate and final hosts in both habitats. The Kiel Canal (total of 17 parasite species) showed a lower parasite species richness for A. brama and R. rutilus (14 and 10 parasite species, respectively) than the lake (25 parasite species). A. brama had a higher parasite richness (22 species) than R. rutilus (16 species) in the lake habitat. Most parasites collected were of freshwater origin. Consequently, the observed infection pattern of both fish species in the waterway is mainly influenced by the limited salinity tolerance of freshwater parasites, which are negatively affected even by a salinity of 2.3 to 4.5. In the central Kiel Canal, neither fish species was infected with marine parasites of low host specifity. These parasites are either limited by the low salinity at this sampling site (<4.5 to 6.0) or they cannot enter the canal due to the environmental conditions prevailing in this artificial brackish water habitat. Thus, the canal may comprise a natural barrier preventing the distribution of North Sea parasites into the Baltic Sea. However, the brackish water Baltic Sea nematodes Paracuaria adunca and Cosmocephalus obvelatus were found in R. rutilus from the canal, demonstrating the ability of some parasite species to invade and extend their range of distribution through this man-made shipping route from the Baltic to the North Sea.     

Observations on the Ultrastructure of the Buccal Apparatus in Thigmotrich Ciliates and their Bearing on Thigmotrich-Peritrich Affinities*

SYNOPSIS. In the first use of electron microscopy in a comparative investigation of ciliates belonging to the order Thigmotrichida, ultrastructural data were collected on ciliary organelles of the buccal area. Species studied included members of the genera Ancistrum and Boveria. Analysis of the findings suggest close affinities between thigmotrich and peritrich ciliates. Further comparison with studies on hymenostome (sensu lato) ciliates supportes the hypothesis of a common ancestral stock in the phylogenetic history of all 3 of these groups. Structures very likely homologous in species of hymenostomes, thigmotrichs, and peritrichs include: the undulating membrane, the polykineties, the oral ribs, the filamentous reticulum, and a small field of barren kinetosomes.     

A new noncanonical nuclear genetic code: translation of UAA into glutamate

Deviant genetic codes reported in ciliates share the same feature: one (UGA) or two (UAR) of the three canonical stop codons are translated into one particular amino acid. In many genera, such as Oxytricha, Paramecium, and Tetrahymena, UAR codons are translated into glutamine. UGA is translated into cysteine in Euplotes or into tryptophan in Colpoda inflata and Blepharisma americanum. Here, we show that three peritrich species (Vorticella microstoma, Opisthonecta henneguyi, and Opisthonecta matiensis) translate UAA into glutamate and that at least UAA in O. matiensis is decoded through a mutant suppressor-like tRNA. This kind of genetic code has never been reported for any living organism. Phylogenetic analysis with alpha-tubulin sequences corroborates that peritrichs, peniculines (Paramecium), and hymenostomates (Tetrahymena) form a monophyletic group (class Oligohymenophorea). The differential translation (glu/gln) of UAR codons, the monophyly of the Oligohymenophorea, and the common evolutionary origin of glutamate and glutamine suggest that deviant genetic codes of present-day oligohymenophoreans could have the same origin.     

Comparative and functional morphology of the buccal cavity of Diplogastrina (Nematoda) and a first outline of the phylogeny of this taxon*

The Diplogastrina include about 290 species of free living nematodes. Traditional classifications of this taxon are not based upon hypotheses of phylogenetic relationships. The highly variable structures of the buccal cavity were examined in 21 species using light microscopy and SEM. The function of the stomatal structures was studied with the aid of video recordings of living worms. The morphological data were used to reconstruct a first outline of the phylogenetic relationships of the Dipolgastrina. A rhabditoid gymnostomatal tube which is longer than wide, a short stegostom and a small dorsal tooth as in Pseudodiplogasteroides belong to the stem species pattern of Diplogastrina. Diplogastrina with a ' Rhabditis '-like gymnostomatal tube feed on bacteria and small fungal spores. A short and broad gymnostom as well as a right subventral tooth which forms a functional unit with the dorsal tooth were acquired step by step in the ancestral line leading to Mononchoides and Tylopharynx . The cuticularized cheilostom was divided into six plates connected by pliable regions twice independently within the Diplogastrina. The teeth-bearing posterior part of the buccal capsule can move forewards by pushing apart the plates of the cheilostom so that the teeth can get in contact with food items that are too big to be sucked into the buccal cavity. Diplogastrina with a divided cheilostom can feed not only on bacteria, but also on larger fungal spores, ciliates or other nematodes. Tylopharynx is specialized to rip apart the cell wall of fungal hyphae with the movements of a dorsal and a subventral tooth in order to suck out the contents of the fungus. This shows that the transformation of the buccal cavity in Diplogastrina is linked with an expansion of ecological niches.     

Infraciliature of eight Triplumaria species (Ciliophora, Entodiniomorphida) from Asian elephants with the description of six new species

Intestinal ciliates excreted in the feces of Asian elephants were surveyed. Fourteen species in the order Entodiniomorphida were detected. Nine Triplumaria species in the family Cycloposthiidae were found. Using the silver impregnation, two known species, T. antis and T. dvoinosi, were redescribed and six new species, T. sukuna n. sp., T. zuze n. sp., T. solea n. sp., T. suwako n. sp., T. fulgora n. sp., and T. harpagonis n. sp., were described. T. sukuna, T. zuze, T. solea, and T. suwako have the perivestibular polybrachykinety along the vestibular opening. The buccal infraciliary bands of T. suwako are similar to those of T. selenica found from elephants and the buccal infraciliary bands of T. sukuna, T. zuze, and T. solea are similar to those of T. grypoclunis described from rhinoceroses. T. antis, T. dvoinosi, T. fulgora, and T. harpagonis have the vestibular polybrachykinety extending down inside the vestibulum as found in rumen ciliates in the family Ophryoscolecidae. The caudalial ciliary zones of T. dvoinosi and T. fulgora were retractable as found in rumen ophryoscolecids. Raabena bella and Pseudoentodinium elephantis showed high composition values over 30%. Ciliate densities in the three fecal samples were 0.15, 1.09, and 2.07×10(4)/ml.     

Spiniferites cruciformis: a fresh water dinoflagellate cyst?

Palynological studies of cored lacustrine sediments from the late Quaternary of Lake Kastoria, northern Greece, revealed a Late Glacial interval with abundant dinoflagellate cysts. Cyst assemblages include two identifiable species, Spiniferites cruciformis and Gonyaulax apiculata. The presence of the fresh water species G. apiculata is consistent with the lacustrine setting of these deposits, but that of S. cruciformis is anomalous. Previously, this species has only been recorded in abundance from presumed brackish marine sediments from the Black Sea and Marmara Sea sediments where geochemical data clearly record brackish salinities. Therefore, it has been regarded as a low salinity cyst type with a wide range of morphological variation that some workers have suggested to reflect salinity fluctuations. Specimens from Greece display only part of the range of morphological variability previously described from these (brackish) marine settings. Encountered morphological variation includes ellipsoidal/pentameral and cruciform endocyst shapes with rare intermediate shapes, and highly variable septa development. Specimens characterized by extremely reduced ornamentation known from (brackish) marine environments have not been recorded. Our records of S. cruciformis indicate that: (1) it could thrive in fresh water conditions; and (2) that apparently most of the strong morphological variations of the cysts are an intrinsic phenomenon for this taxon, and may only partly be linked to salinity variations as suggested earlier. We suggest that S. cruciformis essentially is a fresh water taxon, and that its records in (brackish) marine environments, with the exception of specimens with strongly reduced ornamentation, may be due to transportation, to short-lived fresh water surface conditions in such environments, or to tolerance of the species to brackish conditions.