Archiv für Protistenkunde最新文献

Larssoniella n. gen. (Microspora, Unikaryonidae) is characterized by uninucleate stages with a tuft of tubules arising in the cuticle of sporoblasts and in the posterior pole of the young spore in its exospore. L. resinellae n. sp., the type species, has sporoblasts and spores with distinct tubular tufts. Mature spores are smooth, tubular (4.5-5×1.7-2 gym), uninucleate, with polar filament in 10/11 coils. It infects the silk glands, Malpighian tubules, the fat body and gonads of larvae and adults of the Pine resin gall moth, Petrova resinella.

The morphology and morphogenesis of the hypotrichous ciliate Pseudoamphisiella lacazei (Maupas, 1883) SONG, 1996 (formerly Holosficha lacazeiMaupas, 1883) isolated from coastal waters of Qingdao (Tsingtao), People’s Republic of China are described using protargol silver impregnation. Improved diagnoses of the genus Pseudoamphisiella and of P. lacazei are presented. Some characters (the origin of the right marginal cirri and the absence of frontoterminal cirri) are sufficiently different from other hypotrichs to suggest the erection of a new family, Pseudoamphisiellidae, nov. fam. The morphogenetic investigation on P. lacazei shows that the numerous oblique frontoventral transverse (FVT) streaks generate only three rows of cirri: two ventral rows and a row of highly developed transverse cirri. Thus it has midventral rows which, nevertheless, occur in an unusual interphase pattern as two distinctly separate ventral ones. The right marginal row in both proter and opisthe originate, uniquely, from the last FVT-anlage. Generally, all anlagen develop de novo except those of the left marginal row and dorsal kineties, which derive from disaggregated parental cirri or kineties. The parental adoral membranelles and undulating membranes are completely renewed during the cell division. The caudal cirri, which develop from the posterior end of each dorsal kinety anlage, connect with the left and right marginal rows and are therefore very difficult to recognize in the interphase. The phylogenetic position of the new family is discussed but for the time being remains Hypotrichida incertae sedis.

The ultrastructure of Postgaardi mariagerensis is reported for the first time. This biflagellated protist, which is covered by closely and regularly arranged rod-shaped bacteria, was obtained from the sulphidic zone of Burton Lake, Antarctica. There is a large nucleus containing apparently permanently condensed chromatin. The flagella have paraxial rods and emerge from a deep, anteriorly opening pocket. The basal bodies are associated with three asymmetrically arranged microtubular roots. Near the opening of the flagella pocket there is an MTR structure that is continuous with the microtubules of the feeding apparatus. The cell membrane is supported by a corset of evenly spaced and linked parallel microtubules subtended by an electron-dense layer. The cell has batteries of tubular, thick-walled extrusomes with a cruciform internal structure. These ultrastructural features indicate that Postgaardi mariagerensis cannot be regarded as a euglenid (as had been suggested previously) but that it is a member of the Glade Euglenozoa. On current evidence, Posfgaardi cannot be placed in any established subgroup of the Euglenozoa, nor can any subgroup be nominated as a sister taxon to Postgaardi. We therefore suggest that Postgaardi be regarded as Euglenozoa incertae sedis.