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Zusammenfassung Die Art ist durch eine bedeutende Variation der Zellgröße, damit auch des Chromatophors und des Kerns ausgezeichnet. Mit steigender Zellgröße nimmt die Zahl der kontraktilen Vakuolen von zwei auf mindestens acht zu. — Unter Umständen erfolgt exzessive animalische Ernährung; es werden auch im Vergleich zum Zellkörper sehr große Algenzellen aufgenommen und verdaut.  相似文献   

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A new tribe, genus and species of straight-snouted weevils (Dominibrentus leptus, n. gen., n. sp., Dominibrentini, n. tribe; Coleoptera: Brentidae; Cyphagoginae) has been described from Dominican amber. The new taxon is characterised by compressed, ventrolateral concavities on the prothorax and abdomen and lateral concavities on the metathorax for reception of the legs. This is the first representative of a straight-snouted weevil in amber.  相似文献   

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SYNOPSIS. A new species of Paramecium, P. jenningsi , n. sp., from South India, is described. It is like P. aurelia except that nuclei are larger, the cell size is somewhat larger, and the macronuclear anlagen ("placentae") have long-persisting chromatinic centers.  相似文献   

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Several stages of the copepodBasipodella harpacticola n. gen., n. sp., which lives as a parasite on harpacticoid copepods, are described on the basis of four individuals obtained from the Peruvian deep-sea. The taxonomic position of the new species is discussed.  相似文献   

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A new fungal species has been described and placed in the genus Endomyces. Endomyces tetrasperma forms a true septate, multinucleate mycelium which breaks up into arthrospores. Ascus formation occurs after isogamous copulation between sexual protuberances which develop at the ends of arthrospores or between two cells, adjacent mycelial cells, or arthrospores. The asci which dehisce at maturity release two to four smooth, ovoid, thick-walled spores, each containing two oil droplets. The proposed life cycle is based on morphological and cytological observations.  相似文献   

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The morphologies of two novel ciliates, Arcanisutura chongmingensis n. gen., n. sp. and Naxella paralucida n. sp., collected from Shanghai, China, have been investigated using live observation and silver staining methods. Arcanisutura n. gen. can be easily distinguished from related genera by its inconspicuous, oblique anterior suture. Arcanisutura chongmingensis n. sp. is mainly recognized by its elongated body with a tail‐like posterior end, 25–33 somatic kineties, and 4–11 excretory pores. Naxella paralucida n. sp. can be distinguished from its congeners based on its two short nassulid organelles, fusiform trichocysts, 37–49 somatic kineties, and 16 nematodesmal rods. The small‐subunit (SSU) rRNA gene sequences of these two species are presented, revealing the phylogenetic positions of Arcanisutura and Naxella. Phylogenetic analyses show that Arcanisutura forms a sister clade to other synhymeniid genera, namely, Chilodontopsis, Orthodonella, and Zosterodasys; Naxella is most closely related to Nassula spp. and is located within the monophyletic clade of the family Nassulidae.  相似文献   

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From Upper Ordovician Öjlemyrflint erratic boulders of the Kaolinsand (Plio-/Pleistocene) of the Isle of Sylt (North Sea) a problematical microfossil is described which possibly represents an ontogenetical stage of a bilateral-symmetrical animal (? trilobite).  相似文献   

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A problematical, axial-symmetrical microfossil is described from Upper Ordovician Öjlemyrflint erratic boulders of the Isle of Gotland (Baltic Sea) and of the Kaolinsand (Plio-/Pleistocene) of the Isle of Sylt (North Sea).  相似文献   

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Two new yeast species are described:Endomycopsis vini has been isolated from grapes,Pichia etchellsii from fermenting cucumber brines.  相似文献   

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ABSTRACT The morphology and infraciliature of two new, mycophagous soil ciliates are described. Specimens were isolated from dried, rewetted soil samples with the non-flooded Petri dish method and investigated in vivo and with various silver impregnation techniques. Fungiphrya strobli n. g., n. sp. was discovered in the mud of rock-pools on the summit of Table Mountain, Republic of South Africa. It is a holotrichously ciliated, about 50 × 40 μm-sized grossglockneriid with the oral apparatus on the right side of the cell. The adoral ciliature, minute in all other members of the group, is well developed and has a mean of eight kineties forming a conspicuous left, oral polykinetid, highly reminiscent of that found in small species of the genus Colpoda . The ejected extrusomes have a unique, inflated distal end. Grossglockneria ovata n. sp. was discovered in leaf litter from the Lackawanna State Forest in Pennsylvania, USA. It differs from the other members of the genus by the ovate shape, smooth cortex, and the sparse, irregularly-shaped mucocysts. Taxonomic characters and ranking of grossglockneriids are discussed. Because of the complex, unique feeding tube associated with a unique feeding strategy, mycophagy, it is argued that grossglockneriid ciliates should be classified in a separate order, in spite of their close genetic relatedness to members of the order Colpodida.  相似文献   

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In alveolate evolution, dinoflagellates have developed many unique features, including the cell that has epicone and hypocone, the undulating transverse flagellum. However, it remains unclear how these features evolved. The early branching dinoflagellates so far investigated such as Hematodinium, Amoebophrya and Oxyrrhis marina differ in many ways from of core dinoflagellates, or dinokaryotes. Except those handful of well studied taxa, the vast majority of early branching dinoflagellates are known only by environmental sequences, and remain enigmatic. In this study we describe two new species of the early branching dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp. from marine intertidal sandy beach. Molecular phylogeny of the small subunit (SSU) ribosomal RNA and Hsp90 gene places Psammosa spp. as an early branch among the dinoflagellates. Morphologically (1) they lack the typical dinoflagellate epicone-hypocone structure, and (2) undulation in either flagella. Instead they display a mosa?c of dinokaryotes traits, i.e. (3) presence of bi-partite trychocysts; Oxyrrhis marina-like traits, i.e. (4) presence of flagellar hairs, (5) presence of two-dimensional cobweb scales ornamenting both flagella (6) transversal cell division; a trait shared with some syndineansand Parvilucifera spp. i.e. (7) a nucleus with a conspicuous nucleolus and condensed chromatin distributed beneath the nuclear envelope; as well as Perkinsus marinus -like features i.e. (8) separate ventral grooves where flagella emerge and (9) lacking dinoflagellate-type undulating flagellum. Notably Psammosa retains an apical complex structure, which is shared between perkinsids, colpodellids, chromerids and apicomplexans, but is not found in dinokaryotic dinoflagellates.  相似文献   

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In a preliminary cladistic analysis of the bivalve family Cardiidae (Schneider 1992), members of the subfamilies Protocardiinae, Lahilliinae, and Laevicardiinae, plus the genus Nemocardium , were found to be the least derived taxa of cardiids. A cladistic analysis is undertaken of the genera and subgenera of these cardiid taxa, plus several Mesozoic taxa which have never been assigned to any subfamily. The Late Triassic Tulongocardium , which is placed in Tulongocardiinae subfam. n., is the sister taxon to all other cardiids. Protocardiinae is restricted to the genus Protocardia. Most other Mesozoic taxa which have been placed in the Protocardiinae are found to be members of the Lahilliinae. Nemocardium is placed in the Laevicardiinae. Incacardium, Pleuriocardia , and Dochmocardia form a monophyletic group, Pleuriocardiinae subfam. n. Pleuriocardiinae, Laevicardiinae, and the remaining members of the Cardiidae (herein informally termed "cucardiids") form a monophyletic group.  相似文献   

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