额尔齐斯河几种鱼类寄生三代虫种类鉴定及系统发育

对采自额尔齐斯河的银鲫(Carassius auratus gibelio Bloch)、东方欧鳊(Abramis brama orientalis Berg)、黏鲈(Gymnocephalus cernua Linnaeus)、金鳟(Oncorhynchus mykiss Walbaum)感染的三代虫(Gyrodactylus sp.)进行了研究, 通过几丁质结构的形态测量与比较, 初步鉴定寄生于银鲫的为细锚三代(G. sprostonae), 寄生东方欧鳊的为秀丽三代虫(G. elegans), 寄生黏鲈的为普氏三代虫(G. prostate), 寄生金鳟的为细鳞鲑三代虫(G. brachymystacis)。同时将测定的三代虫的ITS序列, 与GenBank上三代虫序列进行比对分析, 发现上述4种三代虫分别与细锚三代虫、秀丽三代虫、细鳞鲑三代虫、普氏三代虫的ITS同源性都在99.3%以上, 进一步验证了形态学的鉴定结果。系统发育分析显示细鳞鲑三代虫和细锚三代虫位于G. (Limnonephrotus)亚属的一枝, 秀丽三代虫和普氏三代虫位于G. (Gyrodactylus)亚属的一枝, 而此两亚属亲缘关系较远。     

常用消毒剂次氯酸钠和二氧化氯对小林三代虫的杀灭效果

为了有效控制三代虫病, 实验以寄生于金鱼的小林三代虫(Gyrodactylus kobayashii)为动物模型, 研究了两种常用消毒剂次氯酸钠溶液(NaClO)和二氧化氯(ClO2)的杀虫效果。结果表明: 在离体(in vitro)条件下, 当NaClO的有效浓度0.2 mg/L或ClO2的有效浓度0.15 mg/L 时, 小林三代虫的平均存活时间均少于2h, 而对照组中小林三代虫的平均存活时间是20.8h。当ClO2的有效浓度0.15 mg/L时, 70%以上的虫体发黑, 而其他浓度处理组, 大部分虫体即使死亡, 虫体依然保持透明。在在体(in vivo)条件下, 当 NaClO的有效浓度0.2 mg/L或ClO2的有效浓度0.5 mg/L 时, 驱虫率都几乎达到100%, 并且驱虫率随着药物浓度的增加而提高,但当ClO2的有效浓度为0.6 mg/L时, 养殖水体出现了白色絮状物。在在体条件下, NaClO的驱虫效果好于ClO2。在金鱼的急性毒性实验中, NaClO和ClO2的安全浓度分别是0.18和0.48 mg/L, 仅稍低于其在在体条件下完全驱除小林三代虫的最小浓度(0.2、0.5 mg/L), 说明次氯酸钠溶液和二氧化氯在驱除三代虫时对金鱼不太安全, 因此, 在治疗金鱼的三代虫病时要慎使次氯酸钠溶液和二氧化氯。然而, 这两种消毒剂能否适用于其他鱼类三代虫病的治疗则有待进一步研究。     

铜鱼寄生三代虫一新种的记述

本文报道我国长江中游铜鱼鳃部寄生的三代虫一新种,即:铜鱼三代虫(新种)Gyrodactylus coreiusisp.nov.,新种的形态特征及其与相近种之间的差别在文中进行了描述和比较。     

秦岭山区虹鳟寄生三代虫一新纪录

记述了秦岭山区寄生于虹鳟的单殖亚纲一新纪录种：细鳞鲑三代虫Gyrodactylus brachymystacis Ergens,1978,比较了其与我国东北寄生于虹鳟的细鳞鱼三代虫Gyrodactylus lenoki Gussev,1953的区别。初步判断其来源可能一是通过水源来源于秦岭的细鳞鲑,另一种是通过早期虹鳟的引进带人的,其真实的途径及其对环境的风险性还有待于进一步研究。     

额尔齐斯河白斑狗鱼假尾复口吸虫的分子鉴定

利用分子生物学方法对采自额尔齐斯河（中国段）的白斑狗鱼（Esox lucius Linnaeus）晶状体内寄生的复口吸虫（Diplostomum）进行了种类鉴定,结果显示其种类为假尾复口吸虫（D.paracaudum）,为中国新记录种。通过PCR扩增待鉴定种的部分18S-ITS1-5.8S序列,测序后与GenBank中假尾复口吸虫的序列进行比对,发现其相似度达到99.6%。将该序列与7种复口吸虫的ITS1序列进行比对后构建系统进化树,进化树以单殖吸虫Gyrodactylus parvae为外类群,结果显示:待鉴定种与假尾复口吸虫（D.paracaudum）聚为一支,其支持率达到了50%以上,支持它们为同一虫种。     

恶性横纹肌样瘤（MRT）的起源研究——高变异率HeLa细胞致裸鼠产生MRT的实验研究

HeLa细胞KB株、X株、NM20／X株、H株的染色体众数依次为60±3（超二倍体）、62±3（超二倍体）、68±3（超二倍体和亚四倍体）和78±2（亚四倍体）,所占比率分别为72%～76%,69%,52%和40%。在纯化3代的肿瘤阴性对照二倍体猫肾（染色体众数38所占比率80%）和犬肾原代细胞皮下接种裸鼠的致癌／致瘤率分别为0%（0／22）和0%（0／10）,X株HeLa细胞冻融裂解物皮下接种裸鼠产生进行性缩小肿瘤的比率为20%（1／5）的前提下,HeLa细胞KB株、X株、NM20／X株皮下接种裸鼠产生进行性生长恶性肿瘤的比率分别为100%（10／ 10）,100%（25／25）和100%（5／5）,H株细胞皮下接种裸鼠产生恶性肿瘤的比率为50%（5／10）。其中,只有HeLa细胞KB株10～11代（染色体结构畸变率高达20%,出现18%双着丝点和2%断片）以超高数量接种的1组4只裸鼠（0.17ml12.75×10     

北极、南极和西藏有壳虫区系与分布

有壳虫(Testacea)是一类常见的自由生活的原生动物,在生态系统物质循环和能量流动中发挥重要作用.作者在分析地球三极(北极、南极、西藏)地区有壳虫种类名录(62属315种)基础上,对有壳虫区系特征、地理分布及其影响因素进行了研究.结果显示,北极地区已记录25科51属232种;南极地区20科30属131种;西藏地区22科42属173种.三个地区物种丰富度最高的属均为砂壳虫属(Difflugia)、匣壳虫属(Centropyxis)、梨壳虫属(Nebela)、鳞壳虫属(Euglypha)和表壳虫属(Arcella);5个属的种数分别占北极、南极、西藏总种数的51.3%、63.4%和60.1%.此外,3个地区共有种数是73(23.2%),共有属数是24(38.7%);仅在1个地区记录的种数是167种(53.0%).在三极地区40个亚区域,苔藓鳞盖虫(Assulina muscorum)和旋匣壳虫(Centropyxis aerophila)的分布最广泛,出现频率均高达90%.聚类分析显示,三个地区种水平相似性系数为51.3-56.3%,属于中等相似,北极和西藏相似系数最大.相似性分析表明,虽然有壳虫具有较强的长距离被动扩散能力,但是一些大于100μm的种类不是全球性分布.有壳虫的地理分布格局与个体大小、生境类型、地质历史事件等密切相关,分析结果受物种鉴定标准、样品数量、空间尺度大小等因素影响.     

新疆叶甲区系及地理分布的初步研究

通过新疆叶甲的系统调查,区系和地理分布的初步研究查明：1）新疆叶甲已知种类有404种（17亚种）,分隶于11亚科78属,其中以隐头叶甲亚科Cryptocephalinae,叶甲亚科Chrysomelinae和跳甲亚科Alticinae的种类最为丰富,分别为87种（7亚种）,97种（2亚种）和71;2）区系组成以古北种占绝对优势,有390种（17亚种）,占种数的96.5%,非古北种14种,仅占3.5%.在古北种中,中亚细亚种156种,占种类数的38.6%,泛古北种102种,占25.2%及特有种、中央亚细亚种和欧洲-西伯利亚种等多种成分;3）叶甲地理分布区域分化明显,北疆阿尔泰山、伊犁-塔城谷盆地、准噶尔盆地、天山北部山地和准噶尔西部山地种类较多,分别有111、159、151、122和77种;占新疆2/3以上面积的东疆和南疆,种类较少,尤其是昆仑山山地,还不足10种;4）地域分化亦明显表现在区系组成上,阿尔泰山的中亚细亚种只有14种,仅占该地叶甲种数的12.6%,欧洲-西伯利亚种、欧洲-鄂毕种和西伯利亚种3种成分合计为45种,占到40.5%;伊犁-塔城谷（盆）地和准噶尔盆地的上述3种成分分别为22种和21种都仅占所在盆地14%左右,而中亚西亚种前者占到46%,后者占到34%;5）将新疆动物区系分为12个省级地理区划单元,根据叶甲在各区划单元的分布,进行区系相似性系数聚类分析,其结果同我们所作的2亚界、3区、5亚区和12个省级单元的区划基本相吻合.     

鳑鮍亚科鱼类鳃部寄生的四种三代虫的记述

据文献记载 ,有关我国三代虫 (Ｇｙｒｏｄａｃｔｙｌｉｎａｅ)的研究始于 1 948年[1],迄今为止 ,已报道三代虫 42种[1—3]。作者在整理、鉴定三代虫标本时发现 ,寄生于两种鳃部的四种三代虫在我国均未见报道 ,其中有两新种 ,现记述如下。量度均以毫米为单位。模式标本保存在中国科学院水生生物研究所鱼病学研究室。1　东湖三代虫 ,新种Ｇｙｒｏｄａｃｔｙｌｕｓｄｏｎｇｈｕｅｎｓｉｓｓｐ .ｎｏｖ .(图 1 )宿主与寄生部位 :中华ＲｈｏｄｅｕｓｓｉｎｅｎｓｉｓＧ櫣ｎｔｈｅｒ的鳃。图 1　东湖三代虫Ｇ .ｄｏｎｇｈｕｅｎｓｉｓｓｐ…     

夏季蓝藻水华期间太湖河口区和敞水区纤毛虫群落组成及水平分布

在太湖北部主要河口区及敞水区域采集纤毛虫样品, 并用定量蛋白银法进行分析。河口区设10个采样点, 敞水区设14个采样点。调查中共检出3纲15目60属的105种纤毛虫, 种类最多的是钩刺目（21种）, 其次是寡毛目（20种）。纤毛虫优势种及其在河口区和敞水区占总丰度比例分别为: 寡毛目的双叉弹跳虫Halteria bifurcate Tamar （12.3%、18.1%）、大弹跳虫H. grandinella Dujardin （12.3%、10.9%）、短列裂隙虫Rimostrombidium brachykinetum Krainer （8.0%、13.4%）、圆筒状似铃壳虫Tintinnopsis cylindrata Kofoid Campbell （11.8%、4.5%）、盾纤目的银灰膜袋虫Cyclidium glaucoma Mller （3.1%、10.8%）。其他常见种类还有: 前口目的趣尾毛虫Urotricha farcta Claparde Lachmann、寡毛目的杯铃壳虫Codonella cratera Leidy、小裂隙虫R. humile Penard、奇异急游虫Strombidium mirabile Penard、小筒壳虫Tintinnidium pusillum Entz、缘毛目的水生钟虫复合种Vorticella aquadulcis complex和钟形钟虫V. campanula Ehrenberg。河口区和敞水区纤毛虫平均丰度分别为31407 cells/L（范围1 600-80 900 cells/L）和18618 cells/L（范围1225 -36000 cells/L）, 平均生物量分别为1322.6 g/L（范围44.6-3119.7 g/L）和543.6 g/L（范围44.0-1570.4 g/L）。两个区域的优势类群相似, 均以寡毛目、前口目、盾纤目和缘毛目为主。但河口区纤毛虫生物多样性（种类丰富度、Simpson多样性指数、Margalef多样性指数、Shannon多样性指数）显著高于敞水区的（P0.05）。统计分析发现, 食藻种类与叶绿素a含量之间无显著相关, 而食菌种类的丰度和叶绿素a含量呈显著正相关关系（P0.001）。由此推测, 纤毛虫群落结构的空间差异可能与水华暴发程度有较大关系。       

Description of Gyrodactylus banmae n. sp. (Monogenea,Gyrodactylidae) parasitic on zebrafish,Danio rerio

A new species of Gyrodactylus was described on the body surface of zebrafish (Danio rerio) in China. Basing on morphological characteristics and ITS sequence, we identified the parasite as a new member of the Gyrodactylus-wageneri group. Morphologically, Gyrodactylus sp. nov. is greatly similar to “G. zebrae”, another species parasitic on zebrafish: both have moderately stout hamulus, marginal hook sickle with a prominent heel and toe, as well as a curved blade. However, distinct haptoral shape differences were detected between these two species. The dorsal bar is straight in Gyrodactylus sp. nov. but strongly curved in “G. zebrae”, and the sickle shaft in Gyrodactylus sp. nov. is approximately perpendicular to the base, but in “G. zebrae” it is slanted downwards. The ITS1-5.8S-ITS2 sequence also indicate that Gyrodactylus sp. nov. exhibits the highest similarity to “G. zebrae”: 95.7% sequence identity suggests interspecific differentiation. Phylogenetic analysis of the ITS1-ITS2 sequence showed that Gyrodactylus sp. nov. formed a sister clade with “G. zebrae”, and exhibited a relatively close phylogenetic relationship with G. kobayashii, G. gurleyi, and G. longoacuminatus, all of which parasitise on goldfish, Carassius auratus. To test the susceptibility of zebrafish and goldfish to the Gyrodactylus sp. nov., ten gyrodactylids were inoculated to the caudal fin of zebrafish and goldfish. The gyrodactylids exhibited the ability to attach themselves to the goldfish, and some gyrodactylids reproduced a few days after the inoculation. On day 9, however, the mean abundance sharply decreased to zero on goldfish and increased to more than 30 on zebrafish. The result suggested that golfish is an unsuitable host for Gyrodactylus sp. nov. Therefore, on the basis of morphology, molecular sequence similarity, and host susceptibility, we conclude that the gyrodactylid found on the zebrafish is a new species, which we named Gyrodactylus banmae.     

A description of a new species Gyrodactylus moldovicus sp. n. (Monogenea: Gyrodactylidae) from the European mudminnow Umbra krameri Walbaum, 1792 from the lower Dnester basin

Gyrodactylus moldovicus sp. n. found on gills, body and in nasal cavities of the European mudminnow (Umbra krameri) differs from G. slovacicus Ergens, 1963 also living on the this host by bigger size of the body, anchors and marginal hooks; from G. cylindriformes Mueller et Van Cleave, 1932 living on the American mudminnow Umbra limi--by bigger size of the body; from G. limi Wood et Mizelle, 1957 also from U. limi--by the form of ventral and dorsal bars and form of marginal hooks. It differs from other freshwater gyrodactylids by special type of marginal hooks which have a hook-like end of the blade. Gyrodactylus moldovicus, G. slovacicus and G. limi have marginal hooks of quite different morphological types. By the morphology of anchors, ventral and sometimes dorsal bars and also morphology of cirrus, G. moldovicus is most related to three species from Cyprininae: G. stankovichi Ergens, 1970, G. longoacuminatus Zitnan, 1964 f. typica and G. shulmani Ling, 1962.     

The description of Gyrodactylus mulli sp. n. (Monogenea: Gyrodactylidae) from the Black Sea blunt-snouted mullet Mullus barbatus ponticus

A new species Gyrodactylus mulli sp. n. is described from the thorax fins of blunt-snouted mullet Mullus barbatus ponticus by the collections of B. E. Bychowsky made in 1947 near Karadag on the Black Sea. Gyrodactylus mulli sp. n. differs from G. alviga Dmitrieva et Gerasev, 2000 (described from blunt-snouted mullet too) in having another morphotype of the marginal hooks. The new species differs from G. proterorhini Ergens, 1967, which has the identical type of the marginal hooks, in having longer membrane of the ventral connective bar, longer point of the anchors, shorter marginal hooks, and lesser size of the cirrus.     

Molecular and morphological comparisons between Gyrodactylus ostendicus n. sp. (Monogenea: Gyrodactylidae) on Pomatoschistus microps (Krøyer) and G. harengi Malmberg, 1957 on Clupea harengus membras L.

Gyrodactylus ostendicus n. sp. was exclusively found on fins of the common goby Pomatoschistus microps (Krøyer). The haptoral hard parts are among the smallest described for species of Gyrodactylus. A presumed similarity between the new species and G. harengi Malmberg, 1957 (subgenus Metanephrotus Malmberg, 1964) encouraged a comparative approach. A morphological analysis showed the marginal hook sickles of G. ostendicus to be of quite a different type and similar to those of G. arcuatus Bychowsky sensu Bychowsky &; Poljansky (1953) (subgenus Mesonephrotus Malmberg, 1964). The new species has a pharynx with short pharyngeal processes. Its protonephridial system has small bladders, indicating an association with the subgenera Mesonephrotus or Metanephrotus. Molecular phylogenetic analyses, including all of the species of Mesonephrotus and Metanephrotus currently available on the GenBank database, suggested that the new species belongs to Mesonephrotus. Combined morphological and molecular studies of the new species show that G. ostendicus is more closely related to G. arcuatus than to G. harengi.     

Four new species of Gyrodactylus von Nordmann, 1832 (Monogenea,Gyrodactylidae) on gobiid fishes: combined DNA and morphological analyses

Four Gyrodactylus species parasitising four closely related gobiid species in European coastal waters were studied and compared with G. arcuatus Bychowsky sensu Bychowsky & Poljansky (1953) from Gasterosteus aculatus . These were G. gondae n. sp. from Pomatoschistus minutus and P. lozanoi , G. flavescensis n. sp. from Gobiusculus flavescens , G. arcuatoides n. sp. from P. minutus and G. branchialis n. sp. from P. microps. Combined molecular and morphological analyses, as well as morphometric and statistical methods, were used. The ssrRNA V4 region and the complete ITS rDNA region were sequenced. Genetically the four new species are clearly distinct from G. arcuatus . From a morphological point of view, the haptoral hard parts of G. gondae n. sp., G. flavescensis n. sp. and G. arcuatoides n. sp. are related to those of G. arcuatus, while these parts of G. branchialis n. sp. are different, but related to those of G. quadratidigitus Longshaw, Pursglove & Shinn, 2003. For the latter two species, a new species group is formed. The V4 and ITS sequence analyses, however, indicate a close relationship between G. branchialis and the three G. arcuatus-like species.     

Parasitic infections in freshwater ornamental fish in Sri Lanka

A total of 1520 ornamental fish of 13 species from 26 export farms in Sri Lanka were collected between October 1999 and March 2000 and examined for parasites. Fish species examined were guppy Poecilia reticulata, goldfish Carassius auratus, platy Xiphophorus maculatus, molly Poecilia sphenops, angel Pterophyllum scalare, swordtail Xiphophorus helleri, tetras Hyphessobrycon species, barbs Capeota and Puntius spp., gourami Colisa sp., carp Cyprinus carpio, fighters Betta spelendens and others (Brachydanio and Astronotus spp.). Nine species of monogenean trematodes (Dactylogyrus extensus, Dactylogyrus cf. extensus, D. vastator, Dactylogyrus cf. vastator Dactylogyrus spp., Gyrodactylus turnbulli, G. katherineri, Gyrodactylus cf. katherineri, Gyrodactylus spp.), 7 protozoan species (Trichodina nigra, Trichodina spp., Tetrahymena corlissi, T. pyriformis, Ichthyophthirius multifiliis, Ichthyobodo necator, Piscinoodinium spp.), 3 species of copepod arthropods (Lernaea cyprinacea, Ergasilus ceylonensis, Argulus foliaceus), 1 metacercarial stage of a digenean trematode (Centrocestus spp.) and 1 nematode (Capillaria spp.) were identified. Parasites were found in fish from 23 of the 26 farms with an overall prevalence of parasitism in 45.3% of fish. The variation in farm prevalence among different parasites was significant (p < 0.01). Fish infection rates with monogenean trematodes, protozoans, copepod crustaceans, digenean trematodes and nematodes were 28.3, 18.4, 4.8, 0.8 and 0.4%, respectively. In all, 50 out of 590 (50/590) guppies were infected with Tetrahymena, compared with 13/930 for all other species, which is a statistically significant result (p < 0.01). Similarly, 13/44 and 18/44 carp were infected with Argulus foliaceus and Lernaea cyprinacea, compared with 7/1476 and 15/1476, respectively, for all other species combined (p < 0.01). Capillaria spp. was found only in guppies (4/590) and angel fish (3/92) while Centrocestus spp. was found in goldfish (12/153) only.