The gut flagellate community of the termite Neotermes cubanus with special reference to Staurojoenina and Trichocovina hrdyi nov. gen. nov. sp

At least seven species of flagellates have been found to inhabit the paunch of the termite Neotermes cubanus. Staurojoenina sp. is the largest species, measuring 100-150mum in length. Three small parabasalids belong to the genera Tritrichomonas, Metadevescovina, and Foaina. A fourth small type is described as Trichocovina hrdyi nov. gen. nov. sp.; the combination of features in this flagellate, such as the presence of a costa, undulating membrane and spiralled dictyosome, does not fit to any known genus. The two oxymonad species do not possess a rostellum. One belongs to the family Polymastigidae; it has one unattached flagellum and three partially attached flagella. The second is a member of the family Pyrsonymphidae, but this one possesses ring-like surface structures, one free flagellum and three spirally attached flagella. It is the first report of a pyrsonymphid in a kalotermitid termite.     

Tritrichomonas mobilensis n. sp. (Zoomastigophorea: Trichomonadida) from the Bolivian squirrel monkey Saimiri boliviensis boliviensis

A trichomonad flagellate, Tritrichomonas mobilensis n. sp., is described from the large intestine of the squirrel monkey, Saimiri boliviensis boliviensis. The organism has a lanceolate body 7-10.5 micrometers in length; a well developed undulating membrane; a stout, tubular axostyle with periaxostylar rings that terminate in a cone-shaped segment projecting from the posterior end of the cell; and a moderately wide costa. The anterior flagella are about as long as the body, and the recurrent flagellum is of the acroneme type. All its characteristics suggest that the new species belongs in the Tritrichomonas augusta type of the subfamily Tritrichomonadinae.     

Tritrichomonas mobilensis n. sp. (Zoomastigophorea: Trichomonadida) from the Bolivian Squirrel Monkey Saimiri boliviensis boliviensis1

ABSTRACT. A trichomonad flagellate, Tritrichomonas mobilensis n. sp., is described from the large intestine of the squirrel monkey, Saimiri boliviensis boliviensis. The organism has a lanceolate body 7–10.5 μm in length; a well developed undulating membrane; a stout, tubular axostyle with periaxostylar rings that terminate in a cone-shaped segment projecting from the posterior end of the cell; and a moderately wide costa. The anterior flagella are about as long as the body, and the recurrent flagellum is of the acroneme type. All its characteristics suggest that the new species belongs in the Tritrichomonas augusta type of the subfamily Tritrichomonadinae.     

Ultrastructure and ribosomal RNA phylogeny of the free-living heterotrophic flagellate Dysnectes brevis n. gen., n. sp., a new member of the Fornicata

Dysnectes brevis n. gen., n. sp., a free-living heterotrophic flagellate that grows under microaerophilic conditions possesses two flagella. The posterior one lies in a ventral feeding groove, suggesting that this flagellate is an excavate. Our detailed electron microscopic observations revealed that D. brevis possesses all the key ultrastructural characters considered typical of Excavata. Among the 10 excavate groups previously recognized, D. brevis displays an evolutionary affinity to members of the Fornicata (i.e. Carpediemonas, retortamonads, and diplomonads). Firstly, a strong D. brevis-Fornicata affinity was recovered in the phylogenetic analyses of small subunit ribosomal RNA (SSU rRNA) sequences, albeit the internal branching pattern of the D. brevis+Fornicata clade was not resolved with confidence. Corresponding to the SSU rRNA phylogeny, D. brevis and the Fornicata shared the following components of the flagellar apparatus: the arched B fiber bridging the right root; a posterior basal body; and a left root. Combining both morphological and molecular phylogenetic analyses, D. brevis is classified as a new free-living excavate in the Fornicata incertae sedis.     

Morphology and Ultrastructure of Cryptobia eilatica n. sp. (Bodonidae: Kinetoplastida), an Ectoparasite from the Gills of Marine Fish

ABSTRACT. A marine kinetoplastid flagellate, Cryptobia eilatica n. sp., is described from the gills of cultured gilt-head sea bream Sparus aurata L. and wild black-spot sea bream Diplodus noct (Valenciennes) in the Red Sea. The trophozoite is elongated and lacks a contractile vacuole and undulating membrane. The body averages 13.5 × 4.1 μm, anterior flagellum 9.7 μm, and free portion of recurrent flagellum 15.2 μm. The ultrastructural features of the species exhibit great similarity to various previously studied Cryptobiids. Cryptobia eilatica trophozoites feed on bacteria, show a preference for the branc hial interlamellar crypts, and attach to the host epithelium by means of the recurrent flagellum. Neither penetration into the epithelial cells, nor any direct damage to host tissue was observed. Cryptobia eilatica inhabits a purely marine habitat, but its trophozoite tolerates salinities as low as 10 ppt.     

Chilomastix equi n.sp., from the Intestine of the Indian Horse

Chilomastix equi n.sp., from the intestine of the Indian horse is described. The normal shape of the body is pyriform, posteriorly drawn out into a spike. The spiral groove is U-shaped and runs from one lateral side to the other. The nucleus is either ovoidal or spheroidal with an eccentric endo-some. Four blepharoplasts are present from which arise the anterior flagella, the cytostomal flagellum and the cytostomal fibrils. The arrangement of the four blepharoplasts differs markedly from the other known species, three being on the anterior border located in one row and the fourth adjacent to the nucleus. The three anterior flagella, arising from the first three anterior blepharoplasts, run backwards. The cytostomal flagellum arises from the fourth blepharoplast and rarely protrudes beyond the broad cytostome. The cytostome has a peculiar shape which distinguishes it from other species. The dimensions of the new species range (in microns) 15.7 to 31.5 in total length, 8.5 to 16.5 in body length proper, 6.0 to 15.5 in breadth and 4.0 to 17.0 in the length of the spike.     

Structure of Monocercomonas sp. as Revealed by Electron Microscopy*

SYNOPSIS. Monocercomonas shares many fine-structural features with all other trichomonads. These include the basic arrangement of the kinetosomes as well as of the recurrent and 3 anterior flagella. The pelta-axostyle complex and the parabasal apparatus, i.e. the Golgi complex and the periodic filaments, also conform to the trichomonad pattern. Of interest with regard to the crucial evolutionary position of Monocercomonas, considered to represent the most primitive trichomonad type, is the fact that it has some structures in common with other Monocercomonadidae and Trichomonadinae and others in common with Devescovinidae and Tritrichomonadinae. Among the former organelles are the marginal lamella and the costal base, and among the latter, the comb-like organelle situated between the infrakinetosomal body and parabasal filament 2 as well as the infrakinetosomal body. No traces of either costa or undulating membrane have been noted, but a complex structure homologous to the marginal lamella of Hypotrichomonas and Trichomonadinae is found underlying the short anteriormost portion of the recurrent flagellum that is attached to the body surface. Observations of sections of selected division stages indicate the potential of parental kinetosomes #1 and #3 to become daughter kinetosome #2.     

Structure and Life Cycle of Trypanoplasma beckeri sp. n. (Kinetoplastida), a Parasite of the Cabezon,Scorpaenichthys marmoratus,in Oregon Coastal Waters*,†

SYNOPSIS. Structure of Trypanoplasma beckeri sp. n. from the cabezon, Scorpaenichthys marmoratus (Ayres), is described from living specimens and from both Giemsa-, and protargol-stained smears. Flagellates from fish blood were usually long and slender, averaging 109.0 × 6.5 fan. The anterior flagellum averaged 8.5 μm; the recurrent flagellum bordered the body and terminated as a very short free flagellum, 2.5 μm long on the average. No true undulating membrane was observed, but in living individuals the recurrent flagellum undulated rapidly near its point of origin. The oval nucleus, averaging 8.5 × 4.0 μm, was located near the anterior cad of the body. An argentophilic, aciculum-like structure appeared to connect the nucleus to the area at the base of the flagella. The kinetoplast was not observed in fish blood forms. On the basis of laboratory experiments, the leech, Malmiana diminuta Burreson, was ascertained to be the vector for T. beckeri. Upon entry into the leech, flagellates became rounded, and division commenced within a few hours. Division continued for ?48 h and the flagellates became progressively smaller until reaching a length of ?10.0 μm. After 72 h they were found in high numbers in the proboscis sheath and also in the anterior crop of the leech. When infected leeches fed on an uninfected fish, flagellates were first observed in the fishes’ peripheral circulation 8 days later.     

Cryptobia udonellae sp. n. (Kinetoplastidea: Cryptobiida) - parasites of the excretory system of Udonella murmanica (Udonellida)

A new cryptobiid flagellates, Cryptobia udonellae sp. n., is described from the excretory channels of Udonella murmanica. The body of flagellates is spindle-shaped. The flagellar pocket is subapical. Two flagella emerge from the pocket. One flagellum turns anterior and is forward-directed; the other flagellum is directed posterior and close to the ventral cell surface. The ventral groove is well developed. The cytostome opens just anterior to the flagellar pocket. The cytostome leads to the short cytopharynx. In the excretory channel of worms the flagellates C. udonellae sp. n. are attached to microvilli of epithelium or lay free in the lumen. Both flagellates have been studied with TEM. The unusual parasite system which involves organisms of four different phylums of animals has been described for the first time.     

Hexamastix dobelli n.sp., a New Trichomonad Parasitic in the Starred Tortoise

Hexamastix dobelli n. sp. (Trichomonadidae) is described from the large intestine of the starred tortoise, Testu-do elegans Schoepff. This is the first species of Hexamastix to be reported from a chelonian. The organism is pyriform, oval, or round in shape. There are five anterior flagella, of which two are long and three short and a single recurrent flagellum, which equals the short anterior flagella in length. The axostyle is very slender and projects for some distance outside the body. The nucleus contains three to six granules and has no endosome. The pelta is crescent-shaped and the parabasal body is rod-like. Perinuclear granules are present in the anterior half of the body. The parasite is 6.0 to 16.5 μ long, 2.0 to 10.3 μ wide and the diameter of nucleus is 2.5 μ.     

Molecular Phylogeny of Parvilucifera prorocentri (Alveolata, Myzozoa): Insights into Perkinsid Character Evolution

ABSTRACT. Perkinsids and colpodellids are lineages that diverged near the origins of dinoflagellates and apicomplexans, respectively, and provide compelling insights into the earliest stages of alveolate evolution. Perkinsids, including Perkinsus and Parvilucifera , are intracellular parasites of animals and dinoflagellates and possess traits also known in syndineans, dinokaryotes (mainly free living dinoflagellates), and colpodellids. An improved understanding of perkinsid biodiversity and phylogeny is expected to shed considerable light on the evolutionary origins of syndineans and dinokaryotes as well as the cellular identities of environmental sequences derived from marine and freshwater habitats. Accordingly, the small subunit (SSU) rDNA sequence from Parvilucifera prorocentri , a tube-forming intracellular parasite of the marine benthic dinoflagellate Prorocentrum fukuyoi , was determined. Molecular phylogenetic analyses demonstrated, with very high statistical support, that P. prorocentri branched as a sister lineage to a divergent clade consisting of Parvilucifera infectans and Parvilucifera sinerae . The entire Parvilucifera clade was nested within a more inclusive and modestly supported clade consisting of Perkinsus and several environmental sequences. Because P. prorocentri possessed a novel combination of ultrastructural features known in Perkinsus, Parvilucifera , and/or syndineans (i.e. germ tubes, trichocysts, and a syndinean-like nucleus), establishing the molecular phylogenetic position of this species enabled us to build a more comprehensive framework for understanding the earliest stages in the evolution of myzozoans.     

Malawimonas jakobiformis n. gen., n. sp. (Malawimonadidae n. fam.): A Jakoba-like Heterotrophic Nanoflagellate with Discoidal Mitochondrial Cristae

Malawimonas jakobiformis n. gen., n. sp., is established for a bacterivorous heterotrophic nanoflagellate isolated from the Malawi shore of Lake Nyasa (eastern Africa). Trophic stages observed were anteriorly biflagellate and naked. The posterior flagellum of a trophic cell resided in a conspicuous groove on the ventral surface, and bore a prominent vane. A Golgi stack and a mitochondrion with discoidal cristae were present anterior to the nucleus. The kinetid consisted of two short, slightly separated basal bodies, four microtubular roots, and associated fibers and bands. The three microtubular roots associated with the posterior basal body were associated with the ventral groove, while the single root associated with the anterior basal body gave rise to secondary cytoskeletal microtubules. Dividing cells became rounded, with persistent flagella. Cysts were uninucleate, and had thin organic walls without clearly differentiated apertures or ornamentation but with conspicuous attachment pads. Kinetid elements were present within cysts. On the basis of microscopical features, especially those of the kinetid, the nearest relatives of M. jakobiformis are the mitochondriate “jakobid” protists (families Histionidae and Jakobidae) and the amitochondriate retortamonads. Malawimonadidae n. fam. is established to accommodate this species.     

Redescription of flagellar arrangement in the duck intestinal flagellate, Cochlosoma anatis and description of a new species, Cochlosoma soricis n. sp. from shrews

Cochlosoma anatis Kotlán (Zoomastigophorea, Retortamonadida, Cochlosomidae), isolated from the large intestines of domestic Rouen ducks, and Cochlosoma soricis n. sp., isolated from the small intestines of shrews, were observed by light and scanning electron microscopy. In both organisms, a single flagellum inserted on the dorsal surface at the same level as the insertion of 4 other flagella on the ventral surface. The 4 ventro-lateral flagella emerged from the left side of the anterior attachment disk below the margin and just above the lateral groove which extended the length of the organism. A 6th flagellum emerged from the margin of the attachment disk. The proximal ends of the flagella formed a bundle with the distal ends becoming unraveled like a rope. During motility, the bundle portion extended straight out from the cell and the free ends of the flagella produced a whipping motion. In C. anatis, the dorsal surface was covered with knob-like lumps and small pits and the cells had an axostyle that emerged slightly to the right of the midline in the posterior 1/3 of the body. The axostylar tip was shorter and thicker than the flagella and in most cells it also had an irregular, knobby appearance. The irregular cell surface and axostyle were absent from C. soricis. The margin of the attachment disk curved toward the center and terminated in C. anatis as a straight edge while in C. soricis it continued as a spiral. Indentations in the mucosal brush border similar to those produced by Giardia, but distinctly belonging to Cochlosoma, were interpreted as points of attachment to the host.     

Effects of calcium on the longituindal flagellum of Oxyrrhis marina

Summary— 2–4 nm filaments represent a new class of cytoskeletal components. They are found in ciliary and flagellar roots and centrosomes of all eucaryotes. They are also the major components of paraflagellar rods (PFR) in Euglena, trypanosomes and dinoflagellates. Oxyrrhis marina, a marine dinoflagellate, possesses a transverse and a longitudinal flagellum. Only the longitudinal flagellum carries the PFR along the proximal two-thirds of its length. This flagellum is not only capable of the classic flagellar beat but is also able to retract and bend, a property mediated by external calcium. To determine if calcium has a direct role in the bending, experimental conditions were established to permeabilization and reactivation. Our conditions to reactivate the axoneme function (wave propagation) appear similar to those observed in the case of the sea urchin sperm. The results show that in vitro, an increase in calcium concentration induces a conformational change of the longitudinal flagellum in the absence of ATP with a half maximum effect at 0.1 μM. In the presence of ATP, this morphology modification causes a total inhibition of the wave propagation which is replaced by non-propulsive contractions of low amplitude. As these properties are not shared by reactivated sea urchin sperm flagella or the transverse flagellum of O marina devoid of PFR, we propose that PFR are responsible for the bending phenomenon. A calcium shock also induces flagellar excision with a half maximum effect at 0.3 μM, and immunofluorescence results suggest that a centrin-like protein is present in O marina and is responsible for this excision.     

<Emphasis Type="Italic">Steinernema costaricense</Emphasis> n. sp. and <Emphasis Type="Italic">S. puntauvense</Emphasis> n. sp. (Rhabditida: Steinernematidae), two new entomopathogenic nematodes from Costa Rica

Steinernema costaricense n. sp. and S. puntauvense n. sp. were recovered during a survey for native entomopathogenic nematodes in Costa Rica. Morphological data, molecular (28S rDNA sequence data) studies and cross-hybridisation tests were used for diagnostic and identification purposes. Additionally, 28S rDNA sequence data were used to assess the evolutionary relationships of the new species with other Steinernema spp. Morphological diagnostic features for S. costaricense n. sp. include: the body size of the infective juvenile (av. 1,696); the presence of protruding 'horn-like' cephalic papillae; the position of the excretory pore in the infective juvenile (av. 77 microm) and the first generation male (av. 117 microm); the D% value of the infective juvenile (av. 53) and the first generation male (av. 56); the E% value of the infective juvenile (av. 85); and the morphology of the spicules and gubernaculum of the first generation male. Diagnostic traits for S. puntauvense n. sp. are: the position of the excretory pore in the infective juveniles (av. 25 microm); the shape and size of the spicules and gubernaculum of the first generation male; and the shape of the tail of the first generation female. In addition to these traits, 28S rDNA sequences analysis and hybridisation tests showed that both new Steinernema species are distinct and unique entities.     

Gyrodiniellum shiwhaense n. gen., n. sp., a new planktonic heterotrophic dinoflagellate from the coastal waters of western Korea: morphology and ribosomal DNA gene sequence

The heterotrophic dinoflagellate Gyrodiniellum shiwhaense n. gen., n. sp. is described from live cells and from cells prepared for light, scanning electron, and transmission electron microscopy. Also, sequences of the small subunit (SSU) and large subunit (LSU) of rDNA have been analyzed. The episome is conical, while the hyposome is ellipsoid. Cells are covered with polygonal amphiesmal vesicles arranged in 16 horizontal rows. Unlike other Gyrodinium-like dinoflagellates, the apical end of the cell shows a loop-shaped row of five elongate amphiesmal vesicles. The cingulum is displaced by 0.3-0.5 × cell length. Cells that were feeding on the dinoflagellate Amphidinium carterae Hulburt were 9.1-21.6 μm long and 6.6-15.7 μm wide. Cells of G. shiwhaense contain nematocysts, trichocysts, a peduncle, and pusule systems, but they lack chloroplasts. The SSU rDNA sequence is >3% different from that of the six most closely related species: Warnowia sp. (FJ947040), Lepidodinium viride Watanabe, Suda, Inouye, Sawaguchi & Chihara, Gymnodinium aureolum (Hulburt) Hansen, Gymnodinium catenatum Graham, Nematodinium sp. (FJ947039), and Gymnodinium sp. MUCC284 (AF022196), while the LSU rDNA is 11-12% different from that of Warnowia sp., G. aureolum, and Nematodinium sp. (FJ947041). The phylogenetic trees show that the species belongs in the Gymnodinium sensu stricto clade. However, in contrast to Gymnodinium spp., cells lack nuclear envelope chambers and a nuclear fibrous connective. Unlike Polykrikos spp., cells of which possess a taeniocyst-nematocyst complex, G. shiwhaense has nematocysts but lacks taeniocysts. It differs from Paragymnodinium shiwhaense Kang, Jeong, Moestrup & Shin by possessing nematocysts with stylets and filaments. Gyrodiniellum shiwhaense n. gen., n. sp. furthermore lacks ocelloids, in contrast to Warnowia spp., Nematodinium spp., and Proterythropsis spp. Based on morphological and molecular data, we suggest that the taxon represents a new species within a new genus.     

Structure of trichomonads as revealed by scanning electron microscopy.

A scanning electron microscope (SEM) study of Hypotrichomonas acosta (Moskowitz), Trichomonas vaginalis Donné, Pentatrichomonas hominis (Davaine), and Tritrichomonas foetus (Riedmüller) provided new information about the structure of the periflagellar canal; emergence of the flagella from the cell body; structure of the undulating membrane; and position, shape, and size of the pelta. Of special interest were the spatial relationships of the attached part of the recurrent flagellum and the accessory filament in Hypotrichomonas and in the members of Trichomonadinae, i.e. Trichomonas and Pentatrichomonas.     

特殊涡鞭毛虫——尖尾虫染色体与典型涡鞭毛虫染色体的比较研究

我们实验室与上海细胞生物学研究所的有关同志多年来在特殊涡鞭毛虫──尖尾虫（Ｏｘｙｒｒｈｉｓｍａｒｉｎａ）的细胞生物学和生物化学上作了一系列的研究,本文所报道的是这些工作中的一部分。对尖尾虫（Ｏｘｙｒｒｈｉｓｍａｒｉｎａ）的永久浓聚染色体的精细形象以及不同固定方法对其精细形象的影响作了观察,并与人肠道细菌的类核体、典型涡鞭毛虫原甲藻（Ｐｒｏｒｏｃｅｎｔｒｕｍｍｉｃａｎｓ）和鞭毛虫眼虫（Ｅｎｇｌｅｎａｓｐ．）的永久浓聚染色体作了比较。结果表明,细菌的类核体的精细形象受固定方法的影响极大。反之,不同的固定方法对于眼虫染色体的精细形象则看不出有任何显著的影响。至于典型涡鞭毛虫类的染色体,单用ＯｓＯ４或用戊二醛－ＯｓＯ４双固定法固定,都会得到典型涡鞭毛虫类染色体的横带样结构,然而单纯用戊二醛固定,却会得到大不相同的形象。在这方面尖角虫的染色体与一般的涡鞭毛虫类的染色体相距甚远,其染色体的精细形象本身也与眼虫类的染色体较为相似,而与一般涡鞭毛虫类的大不相同。本工作所得到的结果与以前我们在不同方面所得到的结果一致。研究结果全都表明,失足虫与典型涡鞭毛虫有着一系列重大的差异,实际上代表着一个介于一般鞭毛虫类与典型涡鞭毛虫类     

Alveolate phylogeny inferred using concatenated ribosomal proteins

Dinoflagellates and apicomplexans are a strongly supported monophyletic group in rDNA phylogenies, although this phylogeny is not without controversy, particularly between the two groups. Here we use concatenated protein-coding genes from expressed sequence tags or genomic data to construct phylogenies including "typical" dinophycean dinoflagellates, a parasitic syndinian dinoflagellate, Amoebophrya sp., and two related species, Oxyrrhis marina, and Perkinsus marinus. Seventeen genes encoding proteins associated with the ribosome were selected for phylogenetic analysis. The dataset was limited for the most part by data availability from the dinoflagellates. Forty-five taxa from four major lineages were used: the heterokont outgroup, ciliates, dinoflagellates, and apicomplexans. Amoebophrya sp. was included in this phylogeny as a sole representative of the enigmatic marine alveolate or syndinian lineage. The atypical dinoflagellate O. marina, usually excluded from rDNA analyses due to long branches, was also included. The resulting phylogenies were well supported in concatenated analyses with only a few unstable or weakly supported branches; most features were consistent when different lineages were pruned from the tree or different genes were concatenated. The least stable branches involved the placement of Cryptosporidium spp. within the Apicomplexa and the relationships between P. marinus, Amoebophrya sp., and O. marina. Both bootstrap and approximately unbiased test results confirmed that P. marinus, Amoebophrya sp., O. marina, and the remaining dinoflagellates form a monophyletic lineage to the exclusion of Apicomplexa.     

Symbiomonas scintillans gen. et sp. nov. and Picophagus flagellatus gen. et sp. nov. (Heterokonta): two new heterotrophic flagellates of picoplanktonic size

Two new oceanic free-living heterotrophic Heterokonta species with picoplanktonic size (< 2 microm) are described. Symbiomonas scintillans Guillou et Chrétiennot-Dinet gen. et sp. nov. was isolated from samples collected both in the equatorial Pacific Ocean and the Mediterranean Sea. This new species possesses ultrastructural features of the bicosoecids, such as the absence of a helix in the flagellar transitional region (found in Cafeteria roenbergensis and in a few bicosoecids), and a flagellar root system very similar to that of C. roenbergensis, Acronema sippewissettensis, and Bicosoeca maris. This new species is characterized by a single flagellum with mastigonemes, the presence of endosymbiotic bacteria located close to the nucleus, the absence of a lorica and a R3 root composed of a 6+3+x microtubular structure. Phylogenetical analyses of nuclear-encoded SSU rDNA gene sequences indicate that this species is close to the bicosoecids C. roenbergensis and Siluania monomastiga. Picophagus flagellatus Guillou et Chrétiennot-Dinet gen. et sp. nov. was collected in the equatorial Pacific Ocean. Cells are naked and possess two flagella. This species is characterized by the lack of a transitional helix and lateral filaments on the flagellar tubular hairs, the absence of siliceous scales, two unequal flagella, R1 + R3 roots, and the absence of a rhizoplast. SSU rDNA analyses place this strain at the base of the Chrysophyceae/Synurophyceae lineages.