A light and electron microscopical study of a new, polymorphic free-living amoeba, Phreatamoeba balamuthi n. g., n. sp

A new amoeba, isolated from well water in Gambia, West Africa, is described and named Phreatamoeba balamuthi n. g., n. sp. Requiring anaerobic conditions for growth, it is easily cultured monoxenically with Escherichia coli or axenically in complex, undefined organic media. Three phenotypes have been observed in the life cycle: an amoeba, a flagellate, and a cyst. The amoeba moves by monopodia, is predominantly multinucleate, and varies from 11 to 160 microns in length. The flagellate has a single flagellum and is from 6 to 50 microns long. The cyst is surrounded by a resistant wall that lacks pores and ranges from 9 to 18 microns in diameter. The transformation from amoeba to flagellate can be induced nutritionally, the exact inducing factor(s) being unknown. Sexual reproduction has not been observed.     

Platyamoeba stenopodia. n. g., n. sp., a Freshwater Amoeba*

SYNOPSIS. Platyamoeba stenopodia n. g., n. sp., isolated from a lake in Alabama, is an amoeba with flattened form, usually more than 2.5 × as long as broad, the anterior half hyaline and the posterior half granular, with a single vesiculate nucleus at the posterior edge of the hyaline region. It forms a transitory floating stage with slender, hyaline pseudopods. Its cyst is spherical, uninucleate, with a smooth inner wall and a thinner, closely applied outer wall, which is often slightly wrinkled. Length of locomotive amoeba 15–36 μ diameter of cyst 7–11.5 μ Reproduction by binary fission with mesomitotic nuclear division, the nuclear membrane disappearing in prophase. The genus Platyamoeba is erected for amoebae including this organism; the type species is P. placida.     

Light and Electron Microscopic Description of a Colorless Euglenoid,Serpenomonas costata n. g., n. sp.1

ABSTRACT. A new genus of rigid, colorless, phagotrophic euglenoid is described from a standing pond on a salt marsh. The cell body measures 21–25 μm long, is about 18 μm wide, has a slight dorso-ventral flattening, and is marked by distinct pellicular ridges. The organism, described as Serpenomonas costata, has two unequal, antapically inserted, heterodynamic flagella. The shorter flagellum is anteriorly directed during swimming and the longer one trails posteriorly. Cells move along the substrate with a creeping motion. The ingestion apparatus is composed of separate ribs extending the length of the cell and is incorporated into the ventral pellicular ridge. The apparatus is independent of the canal and reservoir and is not protrusible. The taxonomic affinities of Serpenomonas with other euglenoids are discussed.     

A New Heterotrophic Cryptomonad: Hemiarma marina n. g., n. sp.

We report a new heterotrophic cryptomonad Hemiarma marina n. g., n. sp. that was collected from a seaweed sample from the Republic of Palau. In our molecular phylogenetic analyses using the small subunit ribosomal RNA gene, H. marina formed a clade with two marine environmental sequences, and the clade was placed as a sister lineage of the freshwater cryptomonad environmental clade CRY1. Alternatively, in the concatenated large and small subunit ribosomal RNA gene phylogeny, H. marina was placed as a sister lineage of Goniomonas. Light and electron microscopic observations showed that H. marina shares several ultrastructural features with cryptomonads, such as flattened mitochondrial cristae, a periplast cell covering, and ejectisomes that consist of two coiled ribbon structures. On the other hand, H. marina exhibited unique behaviors, such as attaching to substrates with its posterior flagellum and displaying a jumping motion. H. marina also had unique periplast arrangement and flagellar transitional region. On the basis of both molecular and morphological information, we concluded that H. marina should be treated as new genus and species of cryptomonads.     

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.     

Light Microscopic Observations, Ultrastructure, and Molecular Phylogeny of Hicanonectes teleskopos n. g., n. sp., a Deep-Branching Relative of Diplomonads

ABSTRACT. We describe Hicanonectes teleskopos n. g., n. sp., a heterotrophic flagellate isolated from low-oxygen marine sediment. Hicanonectes teleskopos has a ventral groove and two unequal flagella, and rapidly rotates during swimming. At the ultrastructural level H. teleskopos is a "typical excavate": it displays flagellar vanes, a split right microtubular root, "I,""B," and "C" fibres, a singlet microtubular root, and a possible composite fibre. Small subunit rRNA (SSU rRNA) gene phylogenies and an "arched" B fibre demonstrate that H. teleskopos belongs to Fornicata (i.e. diplomonads, retortamonads, and relatives). It forms a clade with the deep-branching fornicate Carpediemonas , with moderate-to-strong bootstrap support, although their SSU rRNA gene sequences are quite dissimilar. Hicanonectes differs from Carpediemonas in cell shape, swimming behaviour, number of basal bodies (i.e. 4 vs. 3), number of flagellar vanes (i.e. 2 vs. 3), anterior root organization, and by having a cytopharynx. Like Carpediemonas and Dysnectes, Hicanonectes has conspicuous mitochondrion-like organelles that lack cristae and superficially resemble the hydrogenosomes of parabasalids, rather than the mitosomes of their closer relatives the diplomonads (e.g. Giardia ).     

Erhardorina n. g., Ascogregarina polynesiensis n. sp., Eimeria golemanskii n. sp., Isospora tamariscini n. sp., Gregarina kazumii n. nom., New Combinations and Emendations in the Names of Apicomplexan Protozoa1

On the basis of a review of the approximately 4300 species of apicomplexan protozoa, the following new species, new names, new combinations, and emendations are given: NEW GENUS,Erhardovina; NEW SPECIES,Ascogregarina polynesiensis, Eimeria golemanskii, Isospora tamariscini; NEW NAME,Gregarina kazumii; NEW COMBINATIONS,Ascogregarina brachyceri (Purrini, 1980),Erhardovina euzeti (Lipa, 1981),E. scutovertexi (Erhardová, 1955),Haemorhormidium batrachi (Chaudhuri & Choudhury, 1983); EMENDATIONS,Selenidium francianum(Arvy, 1952) Tuzet & Ormières, 1965,Pyxinioides bolitoides D. P. Henry, 1938,P. japonicus H. Hoshide, 1951,P. kamenote H. Hoshide, 1951,P. kurofuji H. Hoshide, 1951,P. oshoroensis H. Hoshide, 1951,P. pugetensis D. P. Henry, 1938, Gregarina levinei Haldar & Sarkar, 1980,Retractocephalus halticae Haldar, Chakraborty & Kundu, 1982,Cnemidospora schizophylli Tuzet & Guerin, 1947,Grebneckiella indica (Merton, 1911) Watson, 1916,Quadruspinospora atractomorphae Haldar & Chakraborty, 1978,Haemogregarina acipenseri Nawrotzky, 1914,H. lobianci Yakimov & Kohl-Yakimov, 1912,H. yakimovikohlae Wladimiroff, 1910,Hepatozoon luehi (Sambon, 1909) Pessoa, Cavalheiro & de Souza, 1970,Eimeria beyerae Ovezmukhammedov, 1977, E. (?) gigantea (Labbé, 1896) Reichenow, 1921, E. (?) labbei Hardcastle, 1943, E. rufi Prasad, 1960, E. (?) scylii (Drago, 1902) Levine & Becker, 1933, Isospora corvi Ray, Shivnani, Oommen & Bhaskaran, 1952,I. melopsittaci Bhatia, Chauhan, Arora & Agrawal, 1973, I. seicerci Ray, Shivnani, Oommen & Bhaskaran, 1952,I. stomatici Chakravarty & Kar, 1944,I. triffitae Nukerbaeva & Svanbaev, 1973,Wenyonella mackinnonae Misra, 1947,Octosporetla sanguinolentae Ovezmukhammedov, 1975,Lankesterella millani Alvarez Calvo, 1975,Sarcocystis woodhousei Dogel', 1916,Haemoproteus lari Yakunin, 1972, Babesia ninakohlyakimovae (Yakimoff & Shokhor, 1916),Theileria ninakohlyakimovae (Yakimov, 1916) Krylov, 1974,Haemohormidium batrachi(Chaudhuri & Choudhury, 1983).     

Parauronema virginianum n. g., n. sp., a Marine Hymenostome Ciliate

SYNOPSIS. Parauronema virginianum n. g., n. sp., a marine hymenostome ciliate is described from the Virginia coast. Structural studies were made on specimens treated with the Chatton-Lwoff silver impregnation technic and on animals observed with the phase microscope. Particular attention was given to the buccal ciliature and its importance to generic assignment in the order Hymenostomatida.     

Cthulhu Macrofasciculumque n. g., n. sp. and Cthylla Microfasciculumque n. g., n. sp., a Newly Identified Lineage of Parabasalian Termite Symbionts

The parabasalian symbionts of lower termite hindgut communities are well-known for their large size and structural complexity. The most complex forms evolved multiple times independently from smaller and simpler flagellates, but we know little of the diversity of these small flagellates or their phylogenetic relationships to more complex lineages. To understand the true diversity of Parabasalia and how their unique cellular complexity arose, more data from smaller and simpler flagellates are needed. Here, we describe two new genera of small-to-intermediate size and complexity, represented by the type species Cthulhu macrofasciculumque and Cthylla microfasciculumque from Prorhinotermes simplex and Reticulitermes virginicus, respectively (both hosts confirmed by DNA barcoding). Both genera have a single anterior nucleus embeded in a robust protruding axostyle, and an anterior bundle flagella (and likely a single posterior flagellum) that emerge slightly subanteriorly and have a distinctive beat pattern. Cthulhu is relatively large and has a distinctive bundle of over 20 flagella whereas Cthylla is smaller, has only 5 anterior flagella and closely resembles several other parababsalian genera. Molecular phylogenies based on small subunit ribosomal RNA (SSU rRNA) show both genera are related to previously unidentified environmental sequences from other termites (possibly from members of the Tricercomitidae), which all branch as sisters to the Hexamastigitae. Altogether, Cthulhu likely represents another independent origin of relatively high cellular complexity within parabasalia, and points to the need for molecular characterization of other key taxa, such as Tricercomitus.     

Esquamula lacrimiformis n. g., n. sp., a New Member of Thaumatomonads that Lacks Siliceous Scales

We report a new naked cercozoan flagellate, Esquamula lacrimiformis n. g., n. sp., collected from a sandy beach in Japan. Its cells were 4.5–11.3 μm in length and 3.9–8.8 μm in width and possess two unequal flagella. Cells move in a smooth gliding motion and have a trailing long posterior flagellum. Phylogenetic analyses with small and large subunit ribosomal RNA genes revealed that E. lacrimiformis forms a novel lineage within the Thaumatomonadida, the members of which are flagellates with siliceous scales. However, our light and electron microscopic observations indicated that E. lacrimiformis cells do not possess any siliceous structures. Furthermore, other morphological characteristics, such as the shape of the extrusomes and the structural arrangement of the microbody, were clearly different from those of previously described thaumatomonads. On the basis of a combination of these morphological observations and our phylogenetic analyses, we conclude that E. lacrimiformis should be treated as a new species of a new genus and placed into a new family, Esquamulidae n. fam., under Thaumatomonadida.     

Trachyrhizium urniformis n. g., n. sp., a Novel Marine Filose Thecate Amoeba Related to a Cercozoan Environmental Clade (Novel Clade 4)

A novel cercozoan filose thecate amoeba, Trachyrhizium urniformis n. g., n. sp., was isolated from a marine sediment sample collected at Agenashiku Island, Okinawa, Japan. We performed light and electron microscopic observations, and a molecular phylogenetic analysis using the small subunit ribosomal RNA gene of the isolate. Cells of T. urniformis are spherical in shape and are covered by a thin theca possessing a wide rounded aperture. Branching and occasionally anastomosing filopodia with small granules emerge from the aperture. The granules are transported in the filopodia bidirectionally. Transmission electron microscopy showed that cells of T. urniformis possess nucleus with permanently condensed chromatin, Golgi apparatuses, microbodies, mitochondria with tubular cristae, and extrusomes. Several morphological and ultrastructural features of T. urniformis (the presence of thecae and nucleus with permanently condensed chromatin) show similarities with those of Thecofilosea. In a phylogenetic analysis, T. urniformis included in Thecofilosea with weak statistical supports and formed a clade with two sequences that constitutes a cercozoan environmental clade, novel clade 4. On the basis of morphological and ultrastructural information and the results of the phylogenetic analysis, we propose T. urniformis as a new member of class Thecofilosea.     

Two amphistomes,Lobatodiscus australiensis n.g., n.sp. and Elseyatrema microacetabularis n.g., n.sp., from the Australian turtle Elseya dentata (Gray)

Summary Lobatodiscus australiensis n.g., n.sp. (family and subfamily uncertain) and Elseyatrema microacetabularis n.g., n.sp. (family Paramphistomidae, subfamily Dadaytrematinae?), from the intestine of the freshwater turtle Elseya dentata (Gray) in Queensland, Australia, are described. Lobatodiscus has a large lobed acetabulum, small oral diverticula which do not protrude out of the oral sucker, two pairs of lymph vessels and no oesophageal bulb. Elseyatrema has a small acetabulum, large protruding oral diverticula, an oesophageal bulb, juxtaposed testes, one pair of rudimentary lymph vessels and no cirrus-sac. ac]19830626     

A Light- and Electron-Microscopical Study of Protacanthamoeba caledonica n. sp., Type-Species of Protacanthamoeba n. g. (Amoebida,Acanthamoebidae)1

In its amoeboid stage, Protacanthamoeba caledonica n. g., n. sp. closely resembles the genus Acanthamoeba, on both light- and electron-microscopical levels, including possession of a centrosphere with a plaque-shaped centriole-like body. The cyst wall differs from that of Acanthamoeba in lack of preformed exit pores and in fine structure; the occasional apparent division into exocyst and endocyst is due to irregular splitting. The strain isolated from a Scottish estuary did not grow at 37°C and did not grow normally on agar made with 25% sea water, but cysts remained viable after a week in full-strength sea water. Protacanthamoeba n. g. is distinguished from Acanthamoeba on the basis of cyst structure, but it is assigned to the family Acanthamoebidae.     

Occurrence of a New Microsporidan: Enterocytozoon bieneusi n. g., n. sp., in the Enterocytes of a Human Patient with AIDS1

A new microsporidium is reported infesting the enterocytes of a Haitian patient with AIDS. The stages observed were diplokaryotic cells, sporogonial plasmodia, unikaryotic sporoblasts, and spores. Neither a sporophorous vesicle (pansporoblastic membrane) nor parasitophorous vacuole were differentiated around the developmental stages, which were in direct contact with the host cell cytoplasm. The polar tube (5-6 coils) was differentiated before fission of the sporogonial plasmodium. The mature spores measured 1.5 m?m × 0.5 m?. The spore wall was very thin as the endospore was absent or poorly differentiated. The organism is named Enterocytozoon bieneusi n. g., n. sp. and is assigned to the suborder Apansporoblastina.     

Pseudonotohymena antarctica n. g., n. sp. (Ciliophora,Hypotricha), a New Species from Antarctic Soil

A new soil ciliate, Pseudonotohymena antarctica n. g., n. sp., from King George Island, Antarctica, is described based on live observation, protargol impregnation, and its 18S rRNA gene. The new genus Pseudonotohymena is morphologically similar to the genus Notohymena Blatterer and Foissner 1988 in the following characteristics: 18 fronto‐ventral‐transverse cirri, a flexible body, undulating membranes, dorsomarginal kineties, and the number of cirri in the marginal rows. However, Pseudonotohymena differs from Notohymena particularly in the dorsal ciliature, that is, in possessing a nonfragmented dorsal kinety (vs. fragmented). In addition, the molecular phylogenetic relationship of the new species differs from that of Notohymena species. On the basis of the morphological features, the genetic data, and morphogenesis, we establish P. antarctica n. g., n. sp. In addition, the cyst morphology of this species is described.