Revision of the Genus Askenasia Blochmann, 1895, with Proposal of Two New Species, and Description of Rhabdoaskenasia minima N. G., N. Sp. (Ciliophora, Cyclotrichida)

ABSTRACT. The planktonic ciliate genus Askenasia Blochmann, 1895 is reviewed and the new genus Rhabdoaskenasia n. gen. is established. Askenasia is characterized by three circumferential kinety belts and a circumoral wreath of paired argyrophilic granules without recognizable cilia and nematodesmata. A "brush" is absent. Askenasia apparently lacks the key characters of the Haptorida and is thus transferred to the Cyclotrichida, family Mesodiniidae. Rhabdoaskenasia differs from Askenasia in having single files of basal bodies in all kinety belts and club-shaped extrusomes. It possesses a circumoral kinety composed of dikinetids from which nematodesmata originate, forming a distinct rhabdos. Although very similar to Askenasia in its general appearance, R. minima n. sp. could belong to another order. Based on an extensive review of the literature and on silver impregnated specimens the following Askenasia species are recognized and described in detail: A. volvox (Eichwald, 1852) Kahl, 1930, A. stellaris (Leegaard, 1920) Kahl, 1930, A. acrostomia n. sp., and A. chlorelligera n. sp. Askenasia faurei Kahl, 1930 and A. humilis Gajewskaja, 1928 are transferred to the genus Cyclotrichium: C. faurei (Kahl, 1930) n. comb., C. humilis (Gajewskaja, 1928) n. comb. The systematic position of the genus Askenasia is discussed and keys to the genera of the Mesodiniidae and to the species of Askenasia are provided.     

Pelagostrobilidium wilberti n. sp. (Oligotrichea, Choreotrichida): morphology and morphogenesis

Morphology, infraciliature, morphogenetic features, and some ecological data for Pelagostrobilidium wilberti n. sp. are described. This new species was collected from a temporary pond in Magdalena, Buenos Aires province, Argentina, which was sampled monthly from August 2003 to July 2005. The species was found in autumn and winter. Observations were made in vivo and after staining with protargol. Pelagostrobilidium wilberti n. sp. measures 63-84 x 42-49 microm in vivo and is conical in shape, with a posterior spine-like cytoplasmic process. It possesses 6 somatic kineties, with kinety 2 sinistrally curved and shorter than the others. The oral apparatus is composed of 25-32 external and two internal membranelles. The macronucleus is horseshoe-shaped and located beneath the oral apparatus; two or three spherical micronuclei lie dorsally. There is a posterior contractile vacuole. Morphogenesis is hypo-apokinetal and begins dorsally between the curved kinety 2 and kinety 3. After the discovery of this new species, the diagnosis of the genus Pelagostrobilidium was amended.     

多核织毛虫─新种,无性生殖周期中的形态及形态发生

本新种的典型特征为:表膜较薄但不弯曲,无表膜下颗粒;区别于该属其它种的最突出特点是具有多个大核(5.4±1.4);背触毛6列,在第3-4列之间具有一些额外散在的背触毛.口围由42.3±2.2片小膜组成;额、腹、横、尾棘毛恒为:5:5:3结构;本新种的形态发生结果与该属其它种类相同,6列新背触毛原基分别来源于背部的3列老背触毛和腹部的老右缘棘毛,在第3及第4列新背触毛列之间可见新出现并散在的几根背触毛.       

Two new marine scuticociliates,Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., with improved definition of Pseudoplatynematum (Ciliophora,Oligohymenophora)

Two new marine scuticociliates, Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., isolated from coastal waters of Qingdao, northern China, were investigated using live observation and silver impregnations. Sathrophilus planus can be recognized by its elongate and conspicuously flattened body, ca. 16 somatic kineties, single postoral kinety, extremely elongated first kinety row of membranelle 1, and its marine habitat. Among these features, the structure of membranelle 1 is the most characteristic and enables this species to be easily distinguished from its congeners. Pseudoplatynematum dengi is characterized by the following features: cell surface conspicuously strengthened and notched; prominent spines both at anterior and posterior ends of cell; membranelles 1 and 2 three-rowed, membranelle 3 single-rowed; paroral membrane composed of two parts, anterior end of upper part extending to about level of membranelle 2; ca. 20 somatic kineties, one postoral kinety; single prolonged caudal cilium; contractile vacuole caudally positioned. The diagnosis of the genus Pseudoplatynematum was renewed to include some new characteristics revealed by silver impregnation methods.     

Morphology and morphogenesis of a freshwater ciliate, Epistylis chlorelligerum Shen, 1980 (Ciliophora, Peritrichia)

An oligohalobic peritrichous ciliate, Epistylis chlorelligerum Shen, 1980, was collected from a ditch in Hangzhou, China. The morphology, oral infraciliature, and morphogenesis of the species were studied using living and protargol-impregnated specimens. Zooids of E. chlorelligerum are 160-230 × 50-60 μm in vivo, and characterized by green-colored endoplasm containing symbiotic algae. The oral infraciliature presents a well-developed filamentous reticulum linked to the circular fiber of the cytostome; the outer two rows of P3 extend adstomally over P1 and usually enfold it. During binary fission, one daughter cell inherits most part of the old buccal apparatus and the reorganized haplokinety and germinal kinety (Hk' and G'), and new buccal apparatus of the other daughter cell is mostly developed from the original germinal kinety (G) and haplokinety (Hk): new peniculi 2, 3 (2P2, 2P3), new haplokinety (2Hk), and new germinal kinety (2G) are formed from G, while the new peniculus 1 (2P1) and its peristomial extention (2Pk) originate from Hk. The epistomial membrane can be observed until the two sets of buccal apparatus begin to separate from each other.     

Ogasawaracris gloriosus, a new genus and species of possibly extinct grasshopper (Orthoptera: Acrididae) from the Ogasawara Islands

A new grasshopper genus and species of the subfamily Eyprepocnemidinae, Ogasawaracris gloriosus, is described from the Ogasawara Islands, oceanic islands south of Japan. This species has unique characteristics, such as an extraordinarily large body, rugose and very coarse punctation on the lateral surface of the pronotum, and very strong pronotal lateral carinae. Specimens of this new species have rarely been collected and they are known only from the Ogasawara Islands. The species may already be extinct.     

Updated hypothesis on the evolution of oligotrichid ciliates (Ciliophora, Spirotricha, Oligotrichida) based on somatic ciliary patterns and ontogenetic data

The two recently established genera ApostrombidiumXu et al., 2009 and VaristrombidiumXu et al., 2009 and the analysis of ontogenetic data in Strombidium constrictum, S. montagnesi, S. wilberti, Omegastrombidium elegans, and Paratontonia gracillima necessitated a revision of the hypothesis about the somatic ciliary pattern evolution in oligotrichid ciliates. As a consequence, the species-rich genus Strombidium was split, establishing two genera for species with a horizontal girdle kinety posterior to the oral primordium: Opisthostrombidium nov. gen. with the extrusome attachment sites along the anterior margin of the girdle kinety and posterior to the oral primordium and Foissneridium nov. gen. with the extrusome attachment sites distinctly apart from the girdle kinety and anterior to the oral primordium. The ontogenetic data revealed that the Ω-shaped girdle kinety pattern evolved convergently from the Pseudotontonia pattern with its horizontal girdle kinety in the tailed genus Paratontonia and from the Novistrombidium pattern with its dextrally spiralled girdle kinety in the tailless genus Omegastrombidium. The somatic ciliary pattern of the latter genus probably gave rise to the patterns of Apostrombidium and Varistrombidium.     

中国须鳗属鱼类一新种(鱼纲,鳗鲡目,蛇鳗科)

在编写中国动物志(鳗鲡目)过程中,检测了保存于中国科学院动物研究所和上海水产大学历年采集的蛇鳗科鱼类标本,发现其中有1新种,定名为元鼎须鳗Cirrhimu-raena yuanding sp．nov．,以纪念中国第一代鱼类学家朱元鼎教授对中国鱼类学研究的贡献。该新种由于其上颌下表面中央所具有的凹槽和头背部后1/3处的背鳍起点等特征,是已知的其他9种须鳗属鱼类中所特有的特征,可明显区别于本属的已知种类。     

Evolution of ciliary patterns in the Oligotrichida (Ciliophora, Spirotricha) and its taxonomic implications

Although the somatic ciliature of the Oligotrichida typically comprises only a girdle and ventral kinety, a considerable diversity of ciliary patterns occurs. The four main girdle kinety patterns are identically found in tailed and tail-less species. The contractile tail has a complicated and unique ultrastructure and is potentially useful for the cell's movement and/or stabilization during feeding. Accordingly, I assume that this structure has evolved only once, namely, in the Tontoniidae nov. fam., and that the different girdle kinety patterns developed convergently in the tailed and tail-less taxa. Further distinct features suggest the establishment of the families Cyrtostrombidiidae nov. fam. (with cyrtos-like pharyngeal fibres and lack of ventral membranelles and endoral) and Pelagostrombidiidae nov. fam. (with neoformation organelle). An attempt is made to reconstruct the evolution of the kinety patterns based on morphologic, ontogenetic, and ultrastructural data. Some genera of tail-less Oligotrichida base on differences in the ciliary pattern; Omegastrombidium nov. gen. is erected for a further girdle kinety pattern. Likewise, the tailed genus Tontonia is split, resulting in two new genera, viz., Pseudotontonia nov. gen. and Spirotontonia nov. gen. Furthermore, the genus Spirostrombidium is split due to the different origin of the parallel course of girdle and ventral kinety, and Parallelostrombidium nov. gen. is established. However, the genus Thigmostrombidium is rejected because its enlarged thigmotactic membranelles are interpreted as an adaptation to the benthic lifestyle, which occurred several times within different girdle kinety patterns.     

Establishment of a new amphileptid genus, Apoamphileptus nov. gen. (Ciliophora, Litostomatea, Pleurostomatida), with description of a new marine species, Apoamphileptus robertsi nov. spec. from Qingdao, China

A new pleurostomatid genus Apoamphileptus is described, which is diagnosed as: Belonging to the Amphileptidae with spica on right side; on each side of the cell, a single perioral kinety, which encircles the cytostome and does not extend to the posterior end of the cell; somatic kineties of both sides near ventral margin shortened and forming a postoral suture; two to several extra fragments with densely arranged dikinetids located in anterior portion of left side. As the type species, the morphology and infraciliature of Apoamphileptus robertsi nov. spec., isolated from a shrimp-farming pond near Qingdao (Tsingtao), China, have been investigated using living observations and the protargol silver impregnation method. The diagnosis for this new species is: Apoamphileptus 90-180 x 30-60 microm in vivo, body elongate pyriform-shaped and slightly flattened; with one cross-striated band along the cytostome; 2-6 (generally 4) large macronuclear nodules, one micronucleus; 33-43 right somatic kineties; left side 6-8 kineties; two extra anterior fragments on left side; about 13 contractile vacuoles dispersed throughout whole body; extrusomes absent or not recognizable; marine habitat. Some morphologically related morphotypes are discussed and tabulated. Regarding the pattern of infraciliature and other morphological features, the well-described fresh-water species, Amphileptus claparedii Stein, 1867 is believed to be a member of this new genus, hence a new combination is suggested: Apoamphileptus claparedii (Stein, 1867) nov. comb.     

Description of Leptopharynx brasiliensis nov. spec. and Leptopharynx costatus gonohymen nov. subspec. (Ciliophora, Microthoracida)

Using standard morphological methods, we describe one new Leptopharynx species and a new subspecies of L. costatus, both from soil of the neotropic region. Further, we studied two populations of L. costatus costatus. Leptopharynx brasiliensis nov. spec., which was discovered in the Mato Grosso, Brazil, is a large member (60μm) of the genus with an enormous oral basket. It differs from similar congeners in having six monokinetids in kinety 6, widely spaced kinetids in kinety 1, and an average of 294 kinetids. Leptopharynx costatus gonohymen nov. subspec., which was discovered in southern Florida, makes a small (35μm) and a large morph (55μm) both with narrow oral basket. The small morph is inseparable from the small morph of L. costatus costatus, while the large morph has right-angled adoral membranelles and widely (vs. narrowly) spaced kinetids in kinety 1. The small morphs of a Brazilian and an Austrian L. costatus match Mexican and other European populations, all having on average 181-187 kinetids. As yet, we know four morphs of L. costatus that differ by body size (small vs. large), the oral basket (narrow vs. wide), membranelle 1 (present vs. absent), and the arrangement of the membranelles (flat vs. angled).     

Reconciling cladistic and genetic analyses in choreotrichid ciliates (Ciliophora, Spirotricha, Oligotrichea)

Fifty-six features of halteriid, oligotrichid, and choreotrichid ciliates are cladistically analysed, including an updated hypothesis about the evolution of the somatic ciliary patterns. Based on its morphology, Lynnella clusters with Parastrombidinopsis, Parastrombidium, and Strombidinopsis, while it is basal to the other choreotrichids in the molecular phylogenies. The two clusters of Favella species in small subunit rRNA gene trees are supported by morphological features, justifying a separation at genus and family level. The genus Favella has a smooth lorica surface and a somatic ciliary pattern comprising a left and lateral ciliary field as well as two dorsal kineties and a monokinetidal ventral kinety abutting on the right ciliary field. The new genus Schmidingerella n. gen., established for the second Favella cluster, groups with Metacylis and Rhabdonella in the molecular trees. It differs from Favella in (i) a lorica wall with reticulate surface ridges and minute openings and (ii) a ventral kinety that is distinctly apart from the right ciliary field and composed of a monokinetidal anterior and a dikinetidal posterior portion. The genera Codonaria, Codonella, and Codonellopsis are affiliated with the family Dictyocystidae, whose diagnosis is improved to include the lorica sac.     

A new Diacyclops (Copepoda,Cyclopoida, Cyclopidae) from northwestern Argentina

No species of the genus Diacyclops has been so far cited from continental Argentina. Specimens collected from a roadside pool in the province of Catamarca on a plateau at 3700 m a.s.l. turned out to belong to a new species, Diacyclops andinus, which is described and illustrated in detail for both sexes. Main diagnostic features are: spine formula of swimming legs 3, 4, 4, 4; terminal spines of the distal endopod segment of leg 4 subequal; smooth furcal rami. The new species is a member of the D. bicuspidatus group, and is probably near the base of this line.     

Soil Ciliates from Saudi Arabia, Including Descriptions of Two New Genera and Six New Species

Six soil samples from natural and cultivated sites of Saudi Arabia were investigated for ciliate diversity, using the non-flooded Petri dish culture method, live observation, and silver impregnation. We identified 135 species, all new for the fauna of Saudi Arabia, of which seven were undescribed: Spathidium alqasabi nov. spec.; Enchelyodon alqasabi nov. spec.; Metauroleptus arabicus nov. gen., nov. spec.; Pseudohemisincirra arabica nov. gen., nov. spec.; Saudithrix terricola? Berger, Al-Rasheid and Foissner, 2006; Oxytricha arabica nov. spec.; and Erimophrya monostyla nov. spec. Based on Spathidium alqasabi, S. seppelti foissneri? Vd'a?ny et al., 2006 and S. seppelti etoschense? Foissner et al., 2002 are raised to species rank; for the latter, a new name is required to avoid homonymy: Spathidium fraterculum nov. nom. The new genus Metauroleptus, which possesses two long and two to three short ventral cirral rows, generates all dorsal kineties intrakinetally and produces caudal cirri exclusively in dorsal kinety 1. Metauroleptus belongs to the hypotrichs, while family classification remains doubtful. The same applies to the new hypotrich genus Pseudohemisincirra, which has frontoventral and transverse cirri, while buccal cirri and caudal cirri are absent. The number of species contained in Saudi Arabian soils, including sand dunes, is in the range reported from other regions of the earth, suggesting that ciliates are well adapted to dry habitats, possibly mainly by their ability to produce very resistant resting cysts, most surviving for a long time due to reduced metazoan predation.     

Taxonomic redescriptions of two ciliates, Protogastrostyla pulchra n. g., n. comb. and Hemigastrostyla enigmatica (ciliophora: spirotrichea, stichotrichia), with phylogenetic analyses based on 18S and 28S rRNA gene sequences

The morphology and infraciliature of two stichotrichid ciliates, Gastrostyla pulchra(Perejaslawzewa 1886) Kahl, 1932 and Hemigastrostyla enigmatica(Dragesco and Dragesco-Kernéis 1986) Song & Wilbert, 1997, collected from marine and brackish sediments, were investigated by using living observations and protargol impregnations. Both 18S and 28S rRNA genes of these two species were sequenced. The 18S rDNA show high similarities (98.4%-99.7%) among populations of each species. There is about 94% similarity in 18S rDNA genes between G. pulchra and Gastrostyla steinii, the type species of the genus, which has been confirmed to be an oxytrichid by previous studies. In the phylogenetic trees of 18S, 28S, and combined 18S and 28S rDNA, both G. pulchra and H. enigmatica are consistently placed outside the well-established oxytrichid clade. Based on our analyses and previous ontogenetic data, we conclude that these two species may represent some lower groups in the subclass Stichotrichia, and that G. pulchra should represent a new genus, Protogastrostyla n. g. This new genus, which is morphologically similar to Gastrostyla, differs in its morphogenesis: the apical part of the old AZM is retained combining with the newly built membranelles that develop from the proter's oral primordium; the primary primordia of the dorsal kinety; and marginal primordia commence de novo without a definite contribution from the old structure.     

Dexiotrichides pangi n. sp. (protozoa,ciliophora, scuticociliatia), a new marine ciliate from the north China sea

The morphology, infraciliature, and silverline system of a new marine scuticociliate, Dexiotrichides pangi n. sp. were investigated. The new species is characterized by: size about 45-65 x 20-25 microm in vivo with kidney-like body shape and obliquely truncated semicircle-shaped apical plate; cytostome at bottom of conspicuously depressed oral cavity, which is located at the cell equatorial level; paroral membrane extending anteriorly to membranelle 3; scutica multi-rowed; 33-38 somatic kineties; contractile vacuole near ventral side and subcaudally positioned, opening at posterior end of somatic kinety 3; one oval macronucleus and one small micronucleus; caudal cilium positioned in a small pouch; marine habitat. Based on the data obtained, an improved diagnosis for the genus Dexiotrichides is suggested: body with circular cross-section and conspicuous cilia-free apical plate; buccal cavity conspicuously depressed with cytostome located near or at equatorial level; three membranelles transversely orientated each with 2-3 rows; paroral membrane zigzaging structure, extending to about half of the length of buccal field; multi-rowed scutica; somatic kinety one strongly shortened and terminating anteriorly at posterior end of buccal field; basal bodies in equatorial region arranged usually in circular pattern, while in the anterior portion of somatic kinety 2, basal bodies characteristically in pairs and separated from the posterior part of kinety 2; one caudal cilium.     

缺脊姬蜂属一新种(膜翅目,姬蜂科)

报道在江西省发现的姬蜂科1新种:并斑缺脊姬蜂Arhytis consociata sp.nov..指出了与近似种的主要区别特征.编制了我国已知种检索表.     

Styloconops hamariensis n. sp. in Somalia (Diptera, Ceratopogonidae)

A new species of the genus Styloconops (S. hamariensis n. sp.) is described on material collected in Somalia in the coastal area near Mogadiscio. This ceratopogonid midge is common during the rainy seasons and it has been observed biting on man and cattle. The new species is morphologically similar to S. spinosifrons from which it can be clearly differentiated for at least some diagnostic characters both in the female and male adults.     

New genus and species of the family stichaeidae from Hokkaido,Japan

Specimens of a new genus and species of the stichaeid fish,Leptostichaeus pumilus, were collected from the Okhotsk Sea off Hokkaido in Japan. The present new genus and species clearly differs from all the other genera and species of the stichaeid fishes in the following characters: 3 or 4 pectoral fin rays; 10 or fewer caudal principal rays; 79–82 dorsal spines; no pelvic fin; last interneural spine supporting a single dorsal spine; infraorbital, occipital and lateral line canals absent; moderate size of dorsal spine shorter than eye diameter; membranes of dorsal and anal fins widely connected with caudal fin; a large black spot divided by a yellow band present just above gill cover.