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Showing papers in "Acta Protozoologica in 2000"


Journal Article
TL;DR: The morphology, infraciliature and silverline system of 7 marine scuticociliates including two new species including one new species are described, including Philasterides armatalis p.
Abstract: The morphology, infraciliature and silverline system of 7 marine scuticociliates including two new species are described: Pleuronema coronatum Kent, 1881, Cohnilembus verminus Müller, 1786, Philasterides armatalis p. n., Pseudocohnilembus persalinus Evans & Thompson, 1964, Porpostoma notatum Möbius, 1888, Cyclidium varibonneti sp. n. and Ancistrum crassum Fenchel, 1965. The new species, Philasterides armatalis is identified by the following characteristics: in vivo 50-80 x 18-25 μm with roundly pointed apical end and one prolonged caudal cilium; oral field about 1/3 of cell length; buccal apparatus with distinctly bipartite paroral me mb ne, 16-18 somatic kinety, one macroand one micronucleus; single contractile vacuole caudally located, marine form. The diagnosis of the ew species, Cyclidium varibonneti : small marine Cyclidium in vivo 15-25 x 10-15 μm with two macronuclei; buccal field about 3/4 of cell length; contractile vacuole caudally located near ventral margin; 11-13 bipolar somatic kineties, of which the posterior end of SKn is c nspicuously shortened and that of SKn-1 is composed of densely spaced kinetosomes. Based on the data obtained, the following species are co nsidered to be junior synonyms: Pseudocohnilembus longisetus Evans & Thompson, 1964 and P. marinus Thompson, 1966 (= P. persalinus Evans & Thompson, 1964); Lembus punctatus Kahl, 1928 and Lembus reesi Kahl, 1931 [= Cohnilembus verminus (Müller, 1786)].

72 citations



Journal Article
TL;DR: An extremely wide host spectrum of the endocytobionts could be determined including other Naegleria spp.
Abstract: Summary. A non-thermophilic Naegleria species isolated from an aquarium for ornamental fishes harboured coccoid Gram-negative bacteria of 1µm in diameter as endocytobionts multiplying by binary fission. These intracytoplasmic bacteria, called “KNic” inhibited cy st formation of their host, but not its transformation to the flagellate stage. Consequently the resulting flagellates contained these intracel lular parasites as could be verified by electron microscopy. The endocytic bacteria could not be grown on eight different bacteriological media under va rious atmospheric conditions. The ribbon-like roughly hexagonal surface of the bacteria as shown by SEM is responsible for the spiny appearance a s seen by TEM. The successful axenisation of the infected host amoebae made it possible to harvest pure bacterial suspensions for cocultivatio n assays with different free-living amoebae and Dictyostelium discoideum. As a result, an extremely wide host spectrum of the endocytobionts could be determined including other Naegleria spp., acanthamoebae, and members of the genera Hartmannella, Vahlkampfia, and Balamuthia. Successful infection of four additional Naegleria strains with the coccoid endocytobionts resulted also in impairment of the capability to form cysts but did not interfere with transformation to the flagellate stage. Dictyostelium discoideum as a member of the Acrasiales was also highly susceptible to infection with the Gram-negative bacteria inducing a strong disturbance of their normal aggregation pattern.

35 citations


Journal Article
TL;DR: It is suggested to lump taxa, which are morphologically and/or morphometrically difficult to distinguish, into “complexes”, as it has been done in sibl ing ciliate species, to make testacean alpha-taxonomy more reliable and elegant, especially for field ecologists.
Abstract: Summary. We show that the varieties Centropyxis aerophila aerophila, C. aerophila sphagnicola, and C. aerophila sylvatica, described by Deflandre in 1929 and later recorded by many workers worldwide, cannot be distinguished with the features provided in the or iginal descriptions, and even not with refined morphometrical data. Very likely, this applies also to most varieties and forms describ ed later. Some of these taxa are obviously extremes of variability clines, while others are distinct but morphometrically inseparable (sibling ) species or subspecies, as indicated by concrete morphological traits and/or different ecologies. A representative example is the variety sylvatica, which is a distinct species because it has a unique inner pseudostome (ventral lip perforation) produced by material agglutinated on the dorsal and lateral shell wall. This peculiar feature, first recognised by Bonnet and Thomas (1955), is shown by clear light and scanni ng electron micrographs in the present paper. However, the inner pseudostome is recognisable only on refined investigation. Thus, we sugges t to lump taxa, which are morphologically and/or morphometrically difficult to distinguish, into “complexes”, as it has been done in sibl ing ciliate species. This would make testacean alpha-taxonomy more reliable and elegant, especially for field ecologists. Nomenclaturally, the varieties described by Deflandre (1929) are subspecies because he did not unambiguously indicate that the names were proposed for infrasu bspecific entities.

30 citations


Journal Article
TL;DR: A total of 91 taxa belonging to 30 genera of testate amoebae were established in 10 moss, soil and aquatic samples, collected in the park of the Chulalongkorn University, Bangkok and in the “Khao Yai” National Park, Thailand.
Abstract: Summary. A total of 91 taxa belonging to 30 genera of testate amoebae were established in 10 moss, soil and aquatic samples, collected in the park of the Chulalongkorn University, Bangkok and in the “Khao Yai” National Park, Thailand. Four genera and 18 species of them were announced for the first time to the testacean fauna of Thailand. The morphological and biometrical characterisation of som e rare testaceans like Cyclopyxis intermedia Kufferath, 1932, Cyclopyxis lithostoma Bonnet, 1974, Ellipsopyxis lamottei Bonnet, 1974, and Lamtopyxis cassagnaui Bonnet, 1977, were made using a light and scanning electron microscope. The following synonyms for C. intermedia have been adopted: C. gigantea Bartoo, 1963; C. kahli grandis Chibisova, 1967 and C. bathystoma Chibisova, 1967.

29 citations


Journal Article
TL;DR: An approximately 10 yr-old male Dalmation was admitted to the Exeter Animal Hospital presenting symptoms of continuous urination, polyuria/polydypsia, and regurgitation, which justified the designation of a new species, Tetrahymena farleyi sp.
Abstract: An approximately 10 yr-old male Dalmation was admitted to the Exeter Animal Hospital presenting symptoms of continuous urination, polyuria/polydypsia, and regurgitation. Urinalysis showed glucosuria, pyuria, proteinuria, casts, and white blood ce lls. Microscopic examination of urine revealed considerable numbers of a ciliated protozoan. The ciliate was isolated and asepticall y cultured in proteose peptone medium. Cytological staining of cells with the Chatton-Lwoff silver nitrate and silver proteinate procedure s demonstrated that the ciliate was a species of the genus T trahymena , measuring about 50 x 25 μm, placing it within the “ pyriformis” species complex. Polymerase chain reaction amplification of the small subunit rRNA (SSrRNA) gene followed by DNA sequence analysis conf irmed this identification. Analysis of the complete SSrRNA gene demonstrated significant differences in primary sequence from all oth er embers of the “pyriformis” species complex and justified the designation of a new species, Tetrahymena farleyi sp. n.

27 citations


Journal Article
TL;DR: The present investigation shows that RAPD fingerprinting is a useful method for species separation, but it seems to be of limited use for constructing phylogenetic relationships among the six species investigated.
Abstract: Species separation among six morphologically similar Euplotes spp. was investigated using random amplified polymorphic DNA fingerprinting (RAPD fingerprinting). Distinctly different banding patterns were obtained for each taxon (the band sharing inde x (D) among the six was 0.36-0.59), which indicates that all those concerned are well-defined species. Phylogenetic relationships among the six species were also analyzed using both RAPD fingerprinting and morphological analysis. Based on the molecular data, the ciliates were sp lit into two clusters: E. vannus-minuta-woodruffi-charon , and E. eurystomus-octocarinatus . By contrast, a phenetic dendogram for these six species derived from morphometric characters indicated that they are divided into two rather different clusters, namely E. vannus-minuta-charon and E. eurystomus-octocarinatus-woodruffi. The most significant difference between the two analyses is that E. woodruffi and E. charon belong to two different clusters according to the dendogram based on morphology, but are closely related in the dendogram based on RAPD fingerprinting. The present investigation shows that RAPD fingerprinting is a useful method for species separation, but it seems to be of limited use for constructing phylogenetic relationships among the six species investigated. The results of the morphometric ana lysis support the view that the pattern of the frontoventral cirri, type of silverline system, arrangement of dorsal kineties and the structu re of adoral zone of membranelles are important characters for determining phylogenetic relationships among species of Euplotes, whereas body shape and size are less significant.

26 citations





Journal Article
TL;DR: The data show lower eukaryotic cells may use similar signal transduction pathways as observed in multicellular organisms, and it seems appropriate to use protozoan cells as a model system for multidisciplinary studies of sensory signalTransduction within single cells.
Abstract: Summary. Stentor coeruleus and the related Blepharisma japonicum possess photoreceptor systems that render the cells capable of avoiding light. On account of this unique feature, these ciliates exhibit photodispersal as they tend to swim away from a bright illumin ation and accumulate in shady or dark areas. The observed photobehaviour is largely the result of a step-up photophobic response displaye d by both ciliates, although other behavioral reactions like phototaxis or photokinesis may also contribute to the photodispersal. The ph otophobic response caused by a sudden increase in light intensity (light stimulus) starts with a delayed cessation of ciliary beating tha t results in the disappearance of the cells forward swimming, then a period of ciliary reversal (backward movement) followed finally by renewed forward movement, often in a new direction. Reversal of ciliary beating during the photophobic response correlates with the generation of an action potential. The action potential is elicited by a photoreceptor potential, a transient membrane depolarization produced by the l ight stimulus. The photoreceptor potentials in both ciliates are initiated by light absorption in a cellular photoreceptor system based on hyp ericin-like chromophores - blepharismin in Blepharisma and stentorin in Stentor. Recent evidence indicates that biochemical processes, which couple the photochemical cycle within the cell pigment with photoreceptor potential, may be different in these organisms. In the case of Stentor, cyclic GMP is the probable candidate for an internal second messenger in photosignal transduction. In related Blepharisma cells, however, InsP 3 seems to be responsible for the alterations in membrane potentials and induction of light avoiding response. The data show tha t lower eukaryotic cells may use similar signal transduction pathways as observed in multicellular organisms. Therefore, on the basis o f lightdependent events observed in Blepharisma and Stentor, it seems appropriate to use protozoan cells as a model system for multidisciplinary studies of sensory signal transduction within single cells.



Journal Article
TL;DR: Metacoronympha senta Kirby's report of polygonal compartments, formed by contiguous nuclear membranes, prove by electron microscopy to be microtubules of the axostyles arrayed as a polygon around each nucleus.
Abstract: Metacoronympha senta Kirby (Trichomonadida: Calonymphidae), an exclusive symbiont of Incisitermes (Kalotermitidae) divides by budding and unequal fission, so that large cells can divide to produce both large and small cells. In contrast to M. senta in Incisitermes snyderi from Florida, which has a unimodal population distribution and a maximum cell length of 90 μm, M. senta in I. nr. incisus from Trinidad has a bimodal population distribution with cells as long as 210 μm and with as many as 1000 nuclei, each associated with a mastigont organelle system (karyomastigont). A densely packed parabasal body (Golgi complex) is located on the cell membraneside of each nucleus, which has a typical oval shape. Kirby’s report of “polygonal compartments, formed by contiguous nuclear membranes” prove by electron microscopy to be microtubules of the axostyles arrayed as a polygon around each nucleus. Metacoronympha and other parabasalid symbionts (Coronympha, Trichonympha) of I. snyderi and I. nr. incisus are reported in this second paper ever written on this genus.



Journal Article
TL;DR: It differs from all other cercomonads in its endocommensal habitat, mycophagy, doubled kinetid, distribution of refractile granules and mitochondria, and minimal production of pseudopodia.
Abstract: Summary. The name Cholamonas cyrtodiopsidis gen. n., sp. n., is created for a mycophagous heterotrophic flagellate isolated and cultivated from the intestine of a diopsid fly. Flagellates were subanteriorly biflagellate, uninucleate, and naked. Golgi dictyosomes were anterior to the nucleus, and a reticulate paranuclear body posterior to it. Two groups of refractile bodies were present, one at the anterior end of the cell, the other in the vicinity of the nucleus. Numerous elongate, unbranched mitochondria with tubular cristae were distributed around the periphery and parallel to the long axis of the cell. The kinetid consisted of two symmetrical subunits, each with two basal bodies (one of which was associated with a stubby flagellum), a compound microtubular root, and associated fibers and bands. Cytoskeletal microtubules emanated from the cell anterior and were not associated with any kinetid element. Feeding, on yeast, was accomplished by rapid pseudopodial action at the posterior end of the cell. Cholamonas cyrtodiopsidis is referred to Cercomonadida because it possesses a paranuclear body and has a kinetid architecture similar to some species of Cercomonas. It differs from all other cercomonads in its endocommensal habitat, mycophagy, doubled kinetid, distribution of refractile granules and mitochondria, and minimal production of pseudopodia.


Journal Article
TL;DR: Life histories of three new coccidian parasites obtained from the larvae of three different coleopteran stored-grain pests, Tribolium castaneum Herbst, Alphitobius piceus Olivier and Palorus ratzeburgii Wissmann, respectively, have been described in detail.
Abstract: Summary. Life histories of three new coccidian parasites (Protozoa: Apicomplexa: Coccidia) obtained from the larvae of three different coleopteran stored-grain pests, Tribolium castaneum Herbst, Alphitobius piceus Olivier and Palorus ratzeburgii Wissmann, respectively, have been described in detail. These coccidian parasites belong to the genus Adelina Hesse 1911 and are named as Adelina castana sp. n., Adelina picei sp. n. and Adelina palori sp. n. The complete life histories of these parasites are observed on the fat bodies along with the body fluid of the hosts. A comprehensive comparative account of three life histories is presented in tabular form.


Journal Article
TL;DR: Enhanced production of the appropriate hormone could be induced by hormone treatment (imprinting), which is maintained in the progeny ge nerations, and the experiments support that hormonal imprinting of receptor and hormone production can run parallel.
Abstract: Summary. The unicellular ciliate, Tetrahymena contains molecules which immunologically and functionally resemble to human hormones. Up to now, of the pituitary glycoprotein hormones only the presence of adrenocorticotropic hormone (ACTH) was demonstrated. In the present experiment we observed the presence of molecules immunologically similar to human chorionic gonadotropin (HCG). This hormone-li ke material is localized diffusely in the cell, and in higher amount in the cortical region, in the cilia and in the oral field. After one hour treatment (hormonal imprinting) with luteinizing hormone (LH), follicle stimulating hormone, mixture of these two hormones, HCG, or thyrotropic hor mone (TSH), more fluorescence intensity (given by the hormone) can be observed. Twenty four hours or four days after these treatments the a mount of hormone-like materials seems to be higher, than in the untreated cells or immediately after treatment. The diffuse localization disappears in the body of the cell after LH or FSH treatment and the hormone concentrates peripheral, in the cortex and especially in (or on) the cilia. The largest amount of hormone-like material seems to be present after LH+FSH or TSH treatment. These results mean that in Tetrahymena enhanced production of the appropriate hormone could be induced by hormone treatment (imprinting), which is maintained in the progeny ge nerations. The experiments support that hormonal imprinting of receptor and hormone production can run parallel.



Journal Article
TL;DR: All characteristics of the new mic rosporidium reveal that it is similar to different Amblyosporidae and it is proposed to include it into this family and the new genus Becnelia is proposed.
Abstract: Summary. A microsporidian Becnelia sigarae gen. n., sp. n. (Microspora: Amblyosporidae) was isolated from testes of a water boatman Sigara lateralis (Heteroptera: Corixidae) near Bavorov, South Bohemia, Czech Republic. The life cycle of the pathogen includes a merogony with uninucleate stages, a meiotic sequence in part with binucleate stages (diplokarya) and a sporogony resulting in a persiste nt sporophorous vesicle containing eight spores. Spores are long oval, slightly curved, with broader basis and equally rounded ends, 5 ± 0.5 x 2.5 ± 0.5 µm in diameter. A series ending with early spores serving for autoinfection in the primary host and spread of the infection in oth er tissues differs in ultrastructure of spores. They are shorter and more constricted apically and measure 4 x 2.5 ± 3 µm. Both spore types have a polaroplast with a central part with multiple broad chambers enclosed anteriorly and posteriorly in circular layers of dense lamellae. The spore wall of both types is characterized by a thin exospore and an endospore of equal thickness all over the spore with exception of the attenuated apical pole. Mature spores have an anisofilar polar filament coiled in 9 - 11 turns with first 5 - 6 broader turns and 4 - 5 na rrower turns. The early spores have the filament coiled in 7 turns, of which 4 are broader and 3 narrower. All characteristics of the new mic rosporidium reveal that it is similar to different Amblyosporidae and we therefore propose to include it into this family. The new genus Becnelia is proposed with B. sigarae as a type species. The taxonomic position as well as the relationships to other microsporidia described from Heteroptera are discussed.


Journal Article
TL;DR: Kessler’s goby, a recently introduced fish species in the Budapest region of the river Danube, proved to be infected with two previously undescribed coccidian species.
Abstract: Summary. Kessler’s goby, a recently introduced fish species in the Budapest region of the river Danube, proved to be infected with two previously undescribed coccidian species. The species having a smaller oocyst (7-8.5 µm) proved to be a Goussia and was named G. kessleri sp. n. The species having larger oocysts measuring 13-14 µm showed characteristics typical of an Eimeria and was designated as E. daviesae sp. n. Oocyst of G. kessleri were spherical, contained four ellipsoidal sporocysts lacking Stieda body. Sporocysts measured 5.8 (5-6) x 3.9 (3.8-4) µm. Oocysts of E. kessleri were spherical, contained four short ellipsoidal sporocysts which tapered at one end and formed at that end a cap-like Stieda body. Sporocysts measured 8 (7.5-8.2) x 4.9 (4.8-5.2) µm. Both species formed oocysts in the intestinal e pithelium. The oocysts of the Goussia were released sporulated, while those of the Eimeria passed in unsporulated or semisporulated condition.


Journal Article
TL;DR: The examinations revealed that in 31 cases the amoebae belonged to nonpathogenic E. histolytica, among this one indigenous case; and in two cases were mixed infections, which was in agreement with isoenzymatic and serodiagnostic examinations.
Abstract: Summary. The examinations were carried out on stool and serum samples obtained from 38 Polish citizens infected with E. histolytica sensu lato. Prevalence of infection (according microscopic examinations) was 0.63% in the Polish who come back from abroad and about 0,19 % in persons who did not leave our country. The investigations were performed with isoenzyme analysis and polymerase chain reacti on with the use of specific (Psp, NPsp) and (p11+p12, p13+p14) primers. Serodiagnostic examinations were done with antigen produced fro m E. histolytica HK-9 axenic strain. The examinations revealed that in 31 cases the amoebae belonged to nonpathogenic E. dispar, in 4 to pathogenic E. histolytica, among this one indigenous case; and in two cases were mixed infections. In one case we neither got DNA amplification products nor cultured amoebae. However, from 25 persons we obtained amoebae cultures helping in identification th e amoebae zymodemes. The prevailing zymodeme was nonpathogenic zymodeme I. The PCR results were in agreement with isoenzymatic and serodiagnostic examinations.

Journal Article
TL;DR: The ciliophoran conform to the morphology of the genus Licnophora Claparede, 1867, but differ from all the known species based on body morphology, details of the nuclear apparatus and host preference.
Abstract: Summary. During surveys on the symbionts of intertidal invertebrates, turban shells, Turbo sarmaticus Linnaeus, 1758 and Turbo cidaris cidaris Gmelin, 1791, were found to host heterotrichous ciliophorans on their gills. The ciliophoran conform to the morphology of the genus Licnophora Claparede, 1867, but differ from all the known species based on body morphology, details of the nuclear apparatus and host preference. Based on light and scanning electron microscopy this species is described as a new species, Licnophora bassoni sp. n.

Journal Article
TL;DR: It is supposed that the uniformity of the effe ct of these hormones is not a chance event and they had to be diverged later, later, during the evolution.
Abstract: Summary. Oxytocin and its five analogues (arginin vasopressin included) were studied in chemotaxis assays using Tetrahymena as unicellular model cells. Exclusively the two real hormones (oxytocin and vasopressin) were consequently repellent, other analogues (with ex changed or missed amino acids) were neutral, attractant or unbalanced. Tetrahymena was not able to differentiate qualitatively between oxytocin and vasopressin, however it sharply discriminated the real hormones from the analogues. Considering that in earlier experiments oxytocin and vasopressin also equally influenced the function of the contractile vacuole, it is supposed that the uniformity of the effe ct of these hormones is not a chance event and they had to be diverged (in function) later, during the evolution.