大亚湾养殖鱼类寄生车轮虫的种类组成与季节动态

2017年8月至2018年7月对大亚湾8种养殖鱼类的车轮虫感染情况进行了调查, 采用Lom倡导的“统一特定方法”及Van As & Basson提出的“齿体定位描述法”对采获的车轮虫标本进行了形态鉴定与描述。结果在卵形鲳鲹(Trachinotus ovatus)、星点笛鲷(Lutjanus stellatus)、鞍带石斑鱼(Epinephelus lanceolatus)、眼斑拟石首鱼(Sciaenops ocellatus)和虎龙杂交斑[E. fuscoguttatus (♀) × E. lanceolatus (♂)]等5种鱼上共检获5种车轮虫: 亚卓车轮虫(Trichodina jadranica)、莱普斯车轮虫(T. lepsii)、长须鳠车轮虫(T. guliae)、劳牧小车轮虫(Trichodinella lomi)和斜拟车轮虫(Paratrichodina oblique); 其中卵形鲳鲹5种虫均有寄生, 虎龙杂交斑感染了4种虫, 星点笛鲷、眼斑拟石首鱼和鞍带石斑鱼分别感染了3种、2种和1种虫。周年感染数据表明: 5种虫的感染率均以卵形鲳鲹最高, 眼斑拟石首鱼上2种虫的感染率最低; 莱普斯车轮虫平均感染强度最高的宿主是虎龙杂交斑, 其他4种虫的均是卵形鲳鲹。寄生车轮虫的季节动态表明: 冬季的感染率和平均感染强度较低; 不同虫种感染高峰出现的季节不一, 其中斜拟车轮虫的感染高峰出现在秋季, 其春夏秋季的平均感染强度均大于其他4种虫。研究填补了大亚湾海区鱼类寄生车轮虫研究的空缺, 为该海区车轮虫病的诊断与防控提供了参考。     

The salinity tolerance of trichodinids (Protozoa) parasitic on the Three-spined stickleback Gasterosteus aculeatus

Sticklebacks from a variety of habitats have been examined for trichodinids. Two species of trichodinid were found on fish at every site. They were identified as Trichodina domerguei subsp. domerguei and T. tenuidens , and these identifications are discussed in relation to previous observations by other workers. The tolerance to change in salinity has been examined for both species and the activity of the contractile vacuole of T. domerguei has been examined in detail.     

重庆地区鲫外寄生车轮虫形态分类学研究及一新种的描述(英文)

在对重庆地区进行鱼类寄生虫学的调查过程中,从鲫鳃表获得3种隶属于车轮虫属Trichodina Ehrenberg,1830的外寄生车轮虫,其中含一新种,短棘车轮虫Trichodina brevicirra sp.nov,其典型的鉴别性特征为其短细的齿棘。另外两种车轮虫分别为沃玛车轮虫Trichodina ngoma Van As&Basson,1992与网状车轮虫Trichodina reticulata Hirschman&Partsch,1955;沃玛车轮虫为亚洲新记录种。文章对网状车轮虫的3种群进行了详尽的比较讨论研究,尽管该三种群间存在着细微的种群内差异,但网状车轮虫的典型特征则显而易见地存在于三种群间,即为附着盘中央具有8-16个球状或卵圆形的中央颗粒。       

矩形车轮虫的再描述

目的：我们对泸州市鲇类寄生车轮虫进行调查,对于已经发现,但由于原来的技术水限制需要重新描述的,或缺少资料的车轮虫,给予重新描述或补充新的资料。方法：用国际间统一的千银法染色以显示车轮虫的附着盘结构和口围绕度,用Lom（1958）倡导的”统一的特定方法”（Uniform specific characteristic system）进行测量,用Van＆Bassion（1989）提供的方法描述车轮虫的齿体。结果：对寄生在泸州地区养殖鱼类斑点叉尾鲴（Ietalums punetaus）的鳃上的车轮虫进行了描述,该车轮虫是矩形车轮虫（ Trichodina rectangli）。结论：矩形车轮虫是陈启鎏和谢杏人1964年在青鱼、草鱼等鱼身体上发现的,但是没有显微照片。国际上有许多它的同种异名的车轮虫的描述,这些文献也只有附着盘的显微照片。斑点叉尾鲡是矩形车轮虫的新寄主记录。本研究用国际统一的方法对矩形车轮虫进行描述,并绘出了矩形车轮虫的齿体定位图,提供了完整的统计数据,以及完整的显微照片,即附着盘、口围绕度和细胞核显微照片。     

南中国海野生海水鱼类外寄生车轮虫新记录

研究对采自南中国海的7种海水鱼类进行了调查研究, 并分离获得4种隶属于车轮虫属的种类,分别为浦氏车轮虫Trichodina puytoraci Lom, 1962; 日本车轮虫Trichodina japonica Imai, et al., 1991; 直钩车轮虫Trichodina rectuncinata Raabe, 1958 与鲀车轮虫Trichodina fugu Imai, et al., 1997。研究发现鲀车轮虫Trichodina fugu Imai, et al., 1997为寄主鱼虫纹东方鲀Takifugu vermicularis的病原, 且能在野生条件下将其致死。上述4种车轮虫的形态分类学数据均基于干银法标本获得。研究是对我国南中国海车轮虫的首次报道。       

Host specificity of trichodinid ectoparasites of freshwater fish

Ciliophorons of the family Trichodinidoe comprise seven genera, all of which are commensolists or parasites - mainly on aquatic hosts such as other ciliophorans, coelenterates, planctonic crustaceans, molluscs, echinoderms, amphibians and fish. Although the first species of this family, Trichodina pediculus, was described from material collected from Hydra, most literature concerns the trichodinids of fish-particularly cultured freshwater fish. These ciliophorans have been implicated in severe disease and mortalities of fish, causing severe economic losses in various parts o f the world. In spite o f the confused taxonomy o f the Trichodinidae, it now appears that they fall into four distinct groups representing a line of specialization towards a more exclusive niche on the host fish. The more opportunistic species, with a broad host range, tend to be larger skin parasites, while the more specialized are smaller and usually only parasitize the gills o f their specific host.     

Fecundity of the newts Triturus cristatus, T. marmoratus and their natural hybrids in relation to species coexistence

The two larger newt species in Europe, Triturus cristatus and T. marmoratus , have largely exclusive distributions but live in sympatry in a small area in western France, where they also hybridize. Triturus cristatus is increasing in abundance in the area at the expense of T. marmoratus , although this study shows that T. marmoratus has higher relative lifetime reproductive success. Triturus marmoratus lays more eggs than its relative under controlled conditions, and more T. marmoratus eggs in relation to its relative abundance are found in natural breeding sites. The hybrids are even more fecund, but their eggs and embryos have a lower survival rate.
The data are compared for age at maturity and species longevity, and estimates of lifetime reproductive success show that T. marmoratus females are more fecund than T. cristatus females. There are no differences between the species in survival of the embryos. It is therefore not clear why T. cristatus is replacing T. marmoratus , but changes in terrestrial habitats due to human activity might be the explanation.     

A phylogeny for the Old World newts, genus Triturus: biochemical and behavioural data

A reconstruction is presented of the phylogenetic relationships withing Triturus . Two different data sets are used. Protein electrophoretic data were scored for 19 presumptive gene loci in nine species (Rafinski & Arntzen, 1987) and a set of 16 behaviour characters from the courtship of Triturus was scored for the same nine species. When these are analysed in concernt, a single, fully resolved and robust solution is found. Consequently, two subgenera are recognized: Triturus and Palaeotriton , the former including all te medium- and large-bodied species: T. alpestris, T. vittatus, T. marmoratus, T. cristatus and its three former subspecies ( T. carnifex, T. dobrogicus and T. Karelini ); the latter comprising the small-bodied species: T. bascai, T. italicus, T. helveticus, T. vulgaris and T. montandoni . Within the subgenus Triturus, T. alpestris and T. vittatus are sister taxa to the remaining members of the subgenus. Similarly, T. boscai and T. italicus are a monophyletic group, sister to T. vulgaris, T. helveticus and T. montandoni . Alternative solutions may be found on the basis of a quantitative analysis of the behavioural characters employed in this study. An alternative phylogenetic tree is included as an example.     

Observations on trichodinid ectoparasites (Ciliophora: Peritricha) from the gills of maricultured molluscs in China, with descriptions of three new species of Trichodina Ehrenberg, 1838

During surveys of the trichodinid parasites in mariculture beds off the coast of Shandong Province, China, four species of the genus Trichodina from the gills of marine molluscs were investigated and morphologically studied. Of these, three are described as new: T. ruditapicis n. sp. from Ruditapes philippinarum (Veneridae), T. scapharcae n. sp. from Scapharca subcrenata (Arcidae) and T. mactrae n. sp. from Mactra veneriformis (Mactridae). One little-known species, T. macomarum Raabe & Raabe, 1959, is redescribed from M. veneriformis. Taxonomic and morphometric data for these trichodinids based on wet silver nitrate and protargol-impregnated specimens are presented. For each of the new species, comparisons with closely related species are provided.     

Morphological and molecular characterization of two Trichodina (Ciliophora,Peritrichia) species from freshwater fishes in China

In the present study, we provide morphological and molecular characterization of two Trichodina species, T. acuta Lom, 1970 and T. funduli Wellborn, 1967, isolated from koi (Cyprinus carpio) and loach (Paramisgurnus dabryanus), respectively. Morphological characters of the two Trichodina species were mainly investigated on the basis of dry silver nitrate-impregnated specimens. Both species are medium-sized and possess well-developed denticles comprising strongly sickle-shaped blades, well-developed central parts, and straight rays. Trichodina acuta can be easily distinguished from the other Trichodina species that possess a clear central circle by the well-developed sharp blade apophysis, and the gap between ray tip and central circle. Trichodina funduli is a poorly known species that is easily confused with T. heterodentata Duncan, 1977, however the latter species has thinner denticles. The small subunit ribosomal RNA gene sequences of Trichodina acuta and T. funduli were incorporated into phylogenetic analyses. Our findings suggest that the phylogenetic lineage of trichodinids might not correspond with their living environments, host species or even some morphological characteristics.     

Trichodinid ectoparasites (Ciliophora: Peritrichida) from the gills of cultured marine fishes in China,with the description of Trichodinella lomi n. sp.

Three species of cultured percoids, each heavily infested by trichodinid ectoparasites, were examined from over-wintering pools in Qingdao, China during the winter of 1995. A total of five species of trichodinids belonging to three genera, Trichodinella Sramek-Husek, 1953, Dipartiella Shtein, 1961 and Trichodina Ehrenberg, 1838 were recorded. One new species, Trichodinella lomi n. sp., is described, the denticle of which is characterised by its acutely triangular blade, comma-like central part and inconspicuous ray. The morphology of Trichodina murmanica Poljansky, 1955 was re-investigated. Three other little-known species are redescribed: Dipartiella simplex (Raabe, 1959) Shtein, 1961, Trichodina japonica Imai, Miyazaki & Nomura, 1991 and T. domerguei (Wallengren, 1897).     

Predation and competition within an assemblage of larval newts (Triturus)

The impact of crested newts (Triturus cristatus) on the smaller-bodied palmate and smooth newts (T helveticus and T vulgaris) was studied during the larval stages using a combination of field and laboratory experiments In pond enclosures T cristatus larvae had no effect on the two smaller species over the first four weeks of development By eight weeks, however. T cristatus had achieved a size advantage which enabled it to eliminate T helveticus and severely reduce T vulgaris by predation In laboratory trials under food-limited conditions, T helveticus and T vulgaris were slightly smaller when raised with T cristatus, suggesting that this predatory effect was complemented by interspecific competition during early development Predation of the smaller species started when T cristatus reached a threshold size of c 27 mm No reciprocal effects on T cristatus growth or survival were observed Although T cristatus may be a significant predator of congeneric species in natural ponds, other factors, such as differences in microhabitat selection, higher-order predator-prey interactions and the occasional desiccation of pond habitats may facilitate coexistence between the species     

Trichodinid ectoparasites (Ciliophora: Peritricha) from Misgurnus anguillicaudatus (Cantor) and Anodonta woodiana (Lea) in China, with descriptions of two new species of Trichodina Ehrenberg, 1838

During parasitological surveys in Chongqing, China, three trichodinids infecting a freshwater fish, Misgurnus anguillicaudatus (Cantor), and a mollusc, Anodonta woodiana (Lea), were investigated. Two of these species were found to be new. Trichodina lechriodentata n. sp., from the fish, was identified by its small-sized body and irregularly rectangular blade, while T. rara n. sp., from the mollusc, is characterised by its overall dimensions, denticle morphology and the presence of a white speckle in some specimens. T. modesta Lom, 1979 is also described from the fish. Photomicrographs and morphometric data are presented for all of the species.     

寄生于罗非鱼的刺纹车轮虫种群分析及其寄主偏好性研究

文章在刺纹车轮虫Trichodina centrostrigata Basson, Van As & Paperna, 1983的重描述基础上, 基于形态学特征、分子特征及系统发育分析, 对其种群多样性及寄主偏好性进行了研究。结果表明, 刺纹车轮虫三个种群: Trichodina centrostrigata (KP295473)、Trichodina centrostrigata (W)和Trichodina centrostrigata (Q)在历经4年的时间里, 未发生明显的种群分化; 其次, 刺纹车轮虫与寄生于海水寄主的车轮虫聚支, 表明二者具有较近的亲缘关系; 再次, 刺纹车轮虫主要寄生于鲈形目的广盐性罗非鱼, 少数寄生于其他淡水鱼类, 具有较强的寄生特异性; 最后, 此研究中的寄主罗非鱼对于刺纹车轮虫具有100%的高感染率, 表明刺纹车轮虫为罗非鱼养殖业中一类潜在病害性微生物。     

The effect of pH on feeding behaviour in newt larvae (Triturus: Amphibia)

The feeding responses of three species of newt larvae were compared under circumneutral and sublethal acid conditions. Under acid conditions (pH 4.5) feeding behaviour was suppressed in palmate newts, Triturus helveticus, and smooth newts. T. vulgaris , but not in crested newts, T. cristatus. At low pH, approach and orientation towards food occurred in T. helveticus and T. vulgaris , but snapping was inhibited; T. cristatus snapped and consumed food immediately it was offered under the same conditions. These differences are not consistent with the apparent greater tolerance of T helveticus for acidified ponds. The observations suggest that the chemosensory system of T. helveticus and T. vulgaris may be impaired at low pH.     

Microhabitat selection and feeding relations of smooth and warty newts, Triturus vulgaris and T. cristatus, at an upland pond in mid-Wales

The utilization of microhabitat and food resources by Triturus vulgaris and T. cristatus was studied in an upland pond in mid-Wales. From April to June T. vulgaris was more evenly distributed across the pond than T. cristatus , which showed a preference for the middle of the pond and the bottom of the water column. From July to September however, when most T. vulgaris had left the pond, T cristatus was evenly distributed within the water column and a much higher proportion was captured around the shorelines. Both species appear to be generalist predators with diets limited by prey size. Zooplankton were the most important prey for T. vulgaris , while leeches formed the bulk of the diet of T. cristatus . However, T. cristatus did not select larger-sized zooplankton than T. vulgaris . Large body size therefore enables T. cristatus to consume a wider range of prey sizes than T. vulgaris . Microhabitat niche overlap was greater than feeding niche overlap between the species.     

寄生于重庆地区鲢、鳙及草鱼五种外寄生车轮虫的描述

对采自重庆地区寄生于鲢、鳙及草鱼鳃上的5种外寄生车轮虫进行了形态学及分类学研究,其分别隶属于：车轮虫属、小车轮虫属及三分虫属,其中包含1新种和中国2新纪录。即钝圆车轮虫Trichodina obtusiformis sp．nov．,急尖车轮虫T．acuta Lom,1961,显著车轮虫T．nobilis Chen,1963,周丛小车轮虫Trichodinella epizootica（Rabbe,1950）Sramek-Husek,1953和大型三分虫Tripartiella macrosoma Basson ＆ Van As,1987。文中对新种进行了详细的描述并提供了新种及已知种的附着盘银染标本之显微照片及齿体线条图。