西藏黑斑原鮡消化道寄生蠕虫的群落结构和感染情况

为了解西藏特有鱼类黑斑原鮡(Glyptosternum maculatum)消化道寄生蠕虫的群落结构和感染情况, 于2019年5—8月对383尾黑斑原鮡进行了调查。在黑斑原鮡消化道中共发现7种寄生蠕虫, 分别为深槽绦虫未定种(Bothriocephalus sp.)、原头绦虫未定种(Proteocephalus sp.)、异肉吸虫未定种(Allocreadium sp.)、新棘吻虫未定种(Neoechinorhynchus sp.)、裸鲤棘头虫(Echinorhynchus gymnocyprii)、Contracaecum eudyptulae和杆咽线虫未定种(Rhabdochona sp.), 并对各个物种的形态特征进行了描述。将黑斑原鮡按整个群体、不同性别和不同全长群体进行划分, 分别对其消化道寄生蠕虫的群落多样性和优势虫种进行分析, 并对各寄生蠕虫物种的感染情况进行统计。结果表明: 在黑斑原鮡群体中, 消化道寄生蠕虫群落的Shannon-Wiener指数为1.53, Berger-Parker指数为0.37, 优势物种为C. eudyptulae, 其感染数量、感染率、感染强度和平均丰度均为最高; 在黑斑原鮡不同性别群体中, Shannon-Wiener指数为0.26—1.57, Berger-Parker指数为0.34—0.93, 优势物种为C. eudyptulae, 雄性群体中新棘吻虫未定种也为优势虫种, 两者的感染率和平均丰度均较高; 在黑斑原鮡不同全长群体中, Shannon-Wiener指数为0.22—1.59, Berger-Parker指数为0.34—0.94, 优势物种为C. eudyptulae或新棘吻虫未定种, 感染率和平均丰度基本以二者为最高。研究进一步明确了西藏鱼类寄生虫的种类组成和寄生特点, 为研究体内寄生蠕虫的环境适应性及与宿主的协同进化提供基础资料。     

升金湖和菜子湖越冬白额雁肠道寄生线虫多样性研究

肠道寄生虫是鸟类中常见的病原体之一, 可以传播给人类及其他动物, 引起严重的人禽共患病。通过采集菜子湖和升金湖60份越冬白额雁粪便样本, 以肠道寄生线虫特异引物作为标记基因进行高通量测序, 分析两个湖泊越冬白额雁的肠道寄生线虫感染种类、多样性及其群落组成结构。将3299430条reads归属为肠道寄生线虫门, 共定义3249个肠道寄生线虫的OTUs, 鉴定到4个目, 91属和191种; 4个目分别为小杆目(Rhabditida)(62.12 %)、垫刃目(Tylenchida)(32.20%)、疏毛目(Araeolaimida)(3.40%)和单宫目(Monhysterida)(2.27%), 其中小杆目为优势物种。Shannon-wiener指数和Simpson指数显示, 菜子湖越冬白额雁的肠道寄生线虫alpha多样性高于升金湖越冬白额雁, 而差异性不显著, PCA聚类分析表明, 两个湖泊中越冬白额雁肠道寄生线虫群落的组成结构相似。系统发育关系显示, 样品与湖泊匹配度不高, 部分样品分布不均匀。升金湖和菜子湖越冬白额雁的肠道寄生线虫群落群落结构相似, 可能是由于食物来源相似、食性相似、栖息地环境类似等因素引起寄生虫间的交叉传播与感染导致。通过本研究,初步掌握升金湖和菜子湖越冬白额雁的肠道寄生线虫感染现状, 为进一步探讨越冬白额雁的寄生虫流行病学研究积累基础资料。     

湖北四湖泊营养类型与轮虫群落的关系

对湖北梁子湖水系不同营养类型(中营养型、富营养型)4个湖泊中轮虫的群落结构和物种多样性进行了周年研究,分析比较了不同营养类型湖泊的轮虫种类组成、分布、优势种组成、密度、生物量和多样性指数。结果表明：轮虫的种类数、物种多样性与营养水平呈负相关关系,轮虫密度大体上随营养水平提高而增大,富营养化引起轮虫空间异质性降低,受污染湖泊与非污染湖泊轮虫种类数、寡污性种类数及分布差异尤为明显。用多样性指数评价湖泊营养状态与TLIc方法一致。     

海南尖峰岭国家级自然保护区雨季鱼类群落结构特征研究

为了了解海南尖峰岭国家级自然保护区雨季鱼类群落结构和多样性特征,于2018年8月采用地笼、手抄网等网具对该区域内溪流的鱼类资源进行了调查。结果表明:本次调查共采集到鱼类样本310尾,隶属于6目13科21属23种。新记录鱼类共有14种,其中9种为外来物种。鱼类香农-威纳多样性指数(H')为2. 41,物种丰富度(D)为3. 84,均匀度指数(J')为0. 77,优势度为(λ)为0. 14。与历史资料相比,群落多样性显著升高,同时外来物种入侵生态风险也在升高。该研究结果丰富了尖峰岭国家自然保护区鱼类多样性基础资料,为海南热带雨林国家公园生物多样性保护策略制定提供科学依据。     

长山列岛邻近海域鱼类群落种类组成和多样性时空变化

为了解黄、渤海生态系统交错带长山列岛邻近水域鱼类群落种类组成和多样性,根据2016年10月,2017年1月、5月及8月进行的鱼类资源底拖网调查数据,应用相对重要性指数、物种多样性指数、k优势度曲线等方法,研究了长山列岛邻近海域鱼类群落种类组成、物种多样性时空变化及其与环境因子的关系。结果表明: 该海域共计捕获鱼类77种,以温水性、底层、洄游性鱼类为主,优势种组成季节变化明显,春季、冬季主要优势种为黄鮟鱇,夏季以日本鲭、鳀等中上层鱼类为主。全年共计出现洄游性鱼类46种,季节间物种迁移指数均在100以上,其中秋季物种迁移指数最大。鱼类群落物种丰富度指数在春季最高、Shannon多样性指数和均匀度指数在秋季最高。夏季物种丰富度指数与表层水温呈显著负相关;冬季物种丰富度指数与水深、底层水温呈极显著正相关,Shannon多样性指数与底层水温呈极显著正相关。长山列岛邻近海域作为黄、渤海两大生态系统的交错带,鱼类群落表现出高物种多样性、洄游种多以及明显的时空异质性。     

稻田节肢动物群落的营养联系

根据田间调查和室内饲养观察的资料,研究了稻田节肢动物群落的营养结构及类型。在稻田生态系统中,物种之间由于取食与被取食、寄生与被寄生、捕食与被捕食的营养联系,形成了复杂的食物链和食物网。依据物种在食物网中的位置和功能,可将福州市郊区稻田节肢动物群落的营养结构分为3种类型:1)食物网中尚未发现有重寄生环节;2)食物网中有重寄生环节;3)食物网中有兼寄生环节。为了探讨定量研究生物群落营养联系的可能性,本文运用图论的知识把食物网的结构描述为标向图、集合或邻接矩阵,同时用图论的运算法则解决了各种类型的食物网的合并问题,为研究复杂群落的营养关系提供了一种新方法。     

漓江中下游鱼类物种组成及其多样性研究

2014年4月—2015年1月,按季度对漓江中下游进行了4次鱼类物种多样性调查研究,共采集鱼类10 161尾,计74种,隶属于5目15科55属。以鲤形目为主,占总物种数的66.67%,总个体数的64.29%;且鲤科占优势,占总个体数的59.30%。夏季鱼类多样性指数最高,物种最丰富,春季鱼类多样性相对较低,鱼类物种相对较少。秋冬两季多样性指数相差不大,鱼类的季节变化不明显;春季优势度指数λ最高,优势种较明显;鱼类群落结构相似性分析(ANOSIM)结果显示,平乐县鱼类群落结构与其他采样点间存在显著差异;但鱼类群落的季节性差异不明显。     

浙江大雷山夏蜡梅群落植物物种多样性及其与土壤因子相关性

分别采用物种丰富度、物种多样性指数和群落均匀度等指标对浙江省大雷山夏蜡梅群落植物物种多样性进行测定,并通过相关分析对各种指数与土壤因子的关系进行研究。据10个样地统计,共有维管植物74科、165属、193种。从种子植物属的地理成分来看,温带分布的类型居多。不同群落木本植物的物种丰富度和多样性指数以杉木+木荷林最高,群落均匀度以杉木林最高,毛竹林的各项指数最低。草本植物的物种丰富度以杉木+马尾松林最高,杉木林最低;多样性指数和群落均匀度以竹林最高,短柄枹+格药柃林最低。在不同群落的垂直结构中,乔木层的物种丰富度和多样性指数均小于灌木层,草本层的物种多样性在不同群落间变化较大。相关分析表明,夏蜡梅群落物种多样性与土壤有机质含量相关性较大,其中,木本植物物种多样性与有机质含量显著正相关,草本植物与有机质含量显著负相关。     

鄱阳湖鱼类多样性的时空变化特征研究

研究基于2010年4月、7月和2018年8月、2019年5月在鄱阳湖9个区域的鱼类多样性调查数据,分析鱼类物种多样性、功能多样性和分类差异指数的时空变化以及其与环境之间的关系,了解鄱阳湖近十年来鱼类群落多样性的时空变化特征。结果显示, 2010年和2018—2019年分别调查到鱼类74种和93种,群落结构差异显著(P<0.05),差异贡献率最高的物种为短颌鲚、似鳊、鲫、光泽黄颡鱼和鲤;水温、总悬浮物和叶绿素等环境因素具有显著的年际和季节差异(P<0.05)。与2010年相比, 2018—2019年鱼类物种多样性和功能多样性指数有一定增加,分类差异指数没有显著变化。分类差异指数的随机检验显示(Randomization test),与2010年相比, 2018—2019年位于95%概率置信范围下方的区域增加。水温、总悬浮物和叶绿素等环境因素对物种多样性、功能多样性和分类差异指数有显著的影响(P<0.05)。结果表明,近十年来,鄱阳湖鱼类群落结构发生明显改变,但是小型鱼类依旧是优势种,鱼类群落小型化明显,主要原因可能是过度捕捞的影响。同时,鄱阳湖的人类活动干扰增大,鄱阳县...     

太湖鱼类群落结构及多样性

为了解太湖鱼类群落结构和多样性的分布特征,于2009-2010年利用拖网等网具对该水域的鱼类资源进行了调查.结果表明:本次调查共采获鱼类50种,隶属10目15科40属,其中鲤形目种类最多,占总数的68％;鱼类生态类型以湖泊定居性种类为主,群落优势种为湖鲚(Coilia ectenes taihuensis)、间下鱵(Hyporhamphus intermedius)和陈氏短吻银鱼(Salangichthys jordani)等小型鱼类;与历史资料相比,太湖鱼类的物种数量下降,优势种组成发生较大变化,鱼类群落中体质量＜30 g的小型鱼类占绝对优势,渔业资源小型化趋势明显.由于过度捕捞和湖泊环境恶化,鱼类群落生物多样性指数均表现偏低,物种丰富度指数D为1.54,多样性指数H’N、H’w分别为0.21和0.46,均匀度指数J'N、.J'w分别为0.07和0.14;太湖各湖区间鱼类种群和多样性的差别一定程度上反映出鱼类群落结构与湖泊营养盐、透明度等环境特征相适应的特点.     

Ontogenetic variation in parasite infracommunities of the clingfish Sicyases sanguineus (Pisces: Gobiesocidae)

This study analyzed the variation of the parasite infracommunities and their relationship with the diet and spatial distribution of the clingfish Sicyases sanguineus during its ontogeny. In total, 154 clingfish were collected from the intertidal and the upper subtidal zone of Pacific Ocean along the central Chilean coast. A wide range in body length (1.4-34.5 cm) was observed, including juvenile and adult specimens. Eleven parasite species were found in the clingfish, i.e., 2 Copepoda, 2 Hirudinea, 1 Monogenea, 5 Digenea, and 1 Cestoda. The prevalence, total abundance, Brillouin's diversity index, and the infracommunity species richness increased with fish body length. The parasite communities, the diet, and the spatial distribution changed during clingfish ontogeny, specifically between juveniles (<20 cm body length [BL]) and adults (>20 cm BL). When fish reached a 20-cm BL, a considerable increment in abundance and species richness of parasites was observed; this coincided with an increase in the number of prey items in the diet and with a change of the fish from the intertidal into the subtidal zone. Therefore, the ontogeny of S. sanguineus is important for the variation of parasite infracommunities, which also was associated with dietary and spatial distribution shifts of this fish.     

Metazoan parasite infracommunities of Florida pompano (Trachinotus carolinus) from the coast of the Yucatan Peninsula,Mexico

Metazoan parasite infracommunities of the Florida pompano (Trachinotus carolinus) were studied in terms of species composition, species richness, diversity, numerical dominance, and similarity. Seventy-five fishes were collected from 4 localities along the Yucatan Peninsula coast and 24 parasite species recovered. Most were digeneans (8 species) and nematodes (7). Other species were monogeneans (3). aspidogastreans (2), cestodes (1), acanthocephalans (1), and crustaceans (2). Only 4 species were common in at least I locality. Mean values for species richness, abundance, diversity, numerical dominance, and similarity in total (all species in the individual fish), gastrointestinal, and ectoparasite infracommunities were within ranges observed for most helminth infracommunities of marine fishes from temperate and tropical latitudes. These infracommunities had low species richness, abundance, diversity, and predictability (except ectoparasite infracommunities) and high dominance. Within the predictable element (common species), the specialist monogenean Pseudobicotylophora atlantica was the main reason for the increase in predictability because it was the only common species at all 4 localities. Host feeding habits, the distribution of intermediate hosts and infective stages, the local species pool, and a phylogenetic component seem to be determining the characteristics of these metazoan parasite infracommunities.     

Richness and diversity of helminth communities in the Japanese grenadier anchovy, Coilia nasus, during its anadromous migration in the Yangtze River, China

To determine the relationship between the species richness, diversity of helminth communities, and migration distance during upward migration from coast to freshwater, helminth communities in the anadromous fish Coilia nasus were investigated along the coast of the East China Sea, the Yangtze Estuary, and 3 localities on the Yangtze River. Six helminth species were found in 224 C. nasus . Changes in salinity usually reduced the survival time of parasites, and thus the number of helminth species and their abundance. Except for the 2 dominant helminths, the acanthocephalan Acanthosentis cheni and the nematode Contracaecum sp., mean abundance of other 4 species of helminths was rather low (<1.0) during the upward migration in the Yangtze River. Mean abundance of the 2 dominant helminths peaked in the Yangtze Estuary and showed no obvious decrease among the 3 localities on the Yangtze River. Mean species richness, Brillouin's index, and Shannon index were also highest in the estuary (1.93 ± 0.88, 0.28 ± 0.25, and 0.37 ± 0.34, respectively) and did not exhibit marked decline at the 3 localities on the Yangtze River. A significant negative correlation was not seen between the similarity and the geographical distance (R = -0.5104, P = 0.1317). The strong salinity tolerance of intestinal helminths, relatively brief stay in the Yangtze River, and large amount of feeding on small fish and shrimp when commencing spawning migration perhaps were responsible for the results.     

Parasite community similarity between four Irish lakes

A total of 140 trout were examined from four lakes in north west Ireland, Loughs Craghy, Waskel, Meela and Owennamarve. Eleven species of metazoan parasite were recorded, ten of which were of freshwater origin and Anisakissp. was the only marine species. No acanthocephalan species were found. Diphyllobothrium ditremum, D. dendriticum and Anisakissp. were the only allogenic species. Lough Owennamarve had the largest component community with nine species recorded. Lough Meela, the only brackish water lake had the smallest component community with six species recorded. Lough Waskel and Craghy had intermediate component community values. Lough Meela showed the lowest levels of similarity to any of the other lakes. Values for the Shannon-Wiener diversity index were highest for Lough Owennamarve and lowest for Lough Meela and intermediate for the other two lakes. Lough Meela had the highest values for the Simpson's dominance index and the Berger-Parker index. Lough Owennamarve had the highest Brillouin's index and Lough Meela had the lowest. The use of multiple regression techniques to control for the potentially confounding effect of geographical distance as a predictor of community similarity was discussed. No parasite species found could be considered as regionally and locally abundant and therefore described as a core species. The helminth community appears to have some degree of predictability, but chance colonization events are also important.     

丹江口水库鲤肠道寄生蠕虫群落结构与季节动态

2004年2月到2005年11月在丹江口水库库区206尾鲤(Cyprinus carpio)肠道中检获蠕虫11种,其中复殖吸虫3种,线虫5种,棘头虫2种,绦虫1种。总体感染率为45.63%,平均感染丰度为4.23±12.65,平均感染强度为9.29±17.48,其中饭岛盾腹吸虫(Aspidogaster ijimai)的总感染率(25.24%)和平均感染丰度(1.76±6.46)最大,瓣睾鲫吸虫(Carassatrema lamellorchis)的感染强度(25.00±46.68)最大。除部分平均感染丰度较低的线虫如鲤带巾线虫(Cucullanus cyprini)外,其他蠕虫的分布类型均为聚集分布,蠕虫群落多样性指数为4.63,均匀度指数为0.60,对群落多样性的季节动态分析表明,各季节群落多样性和均匀度波动较大,并无明显变化规律。每尾鲤感染蠕虫种数多在1—4种之间,所有感染的11种蠕虫中优势种为饭岛盾腹吸虫;次优势种为日本侧殖吸虫(Asymphylodora japonica)、中华许氏绦虫(Khawia sinensis)、瓣睾棘吸虫和鲤长棘吻虫(Rhadinarhynchus cyprini);非优势种为对盲囊线虫(Contracaecum sp.)、鲤带巾线虫、鲤杆咽吸虫(Rhabdochona cyprini)、黄颡刺盖线虫(Spinitectus gigi)、毛细线虫(Capillaria sp.)和木村小棘吻虫(Micracanthorhynchina motomurai)。在种间协调关系方面,鲤杆咽线虫和瓣睾鲫吸虫、鲤长棘吻虫和饭岛盾腹吸虫、对盲囊线虫和木村小棘吻虫、鲤长棘吻虫和木村小棘吻虫之间分别存在显著正关联。对优势种和次优势种蠕虫中种群的季节动态分析表明,鲤寄生蠕虫各组分的感染率和平均感染丰度存在显著的季节差异,在秋、冬季节的感染水平普遍比较高,而到春夏则急剧下降,但中华许氏绦虫无显著季节变化。     

Spatial and temporal predictability of the parasite community structure of a benthic marine fish along its distributional range

The search for consistent patterns of organisation in parasite communities remains a central theme in parasite community ecology. However, to date, much evidence comes from studies without replication in both space and time; when replicate communities are examined, repeatable patterns are rarely observed. Here we determine, using nested subset analyses, whether the infracommunities of ectoparasites and endoparasites of a benthic marine fish (Sebastes capensis) show non-random structure. Then we examine the spatial repeatability of parasite community structure across the host's distribution in the southern Pacific, and the temporal repeatability of ectoparasite community structure from one locality. In total, 537 fish were captured from different latitudes (between 11 degrees S and 52 degrees S) along the Pacific coast of South America; a further 122 specimens were captured in two other years from one of the sampling localities, Valdivia (40 degrees S). In spite of variation in fish sizes among samples, fish size generally did not correlate with either ecto- or endoparasite species richness. The ecto- and endoparasite species richness of the component communities were also not correlated with fish sample size across the nine localities. Significant nested patterns were found in the ectoparasite communities of S. capensis at all eight localities, except at latitude 52 degrees S. Significant nested patterns were also found in the endoparasite infracommunities of S. capensis at seven of the nine localities, the exceptions being those from latitudes 11 degrees S and 20 degrees S. On a temporal scale, significant nestedness was observed in the ectoparasite infracommunities of S. capensis during each of the 3 years of sampling at Valdivia. In general, the same parasite species are responsible for the repeatability of nested patterns, though their importance varies among localities. The spatial and temporal predictability of the parasite community structure in S. capensis may be associated with the fish's benthic habitat and territorial behavior, suggesting that host biology may be a key determinant of the structure of parasite communities.     

Helminth assemblages of the turtle Emydura macquarii (Pleurodira: Chelidae) Queensland, Australia

The helminth fauna of 76 Emydura macquarii from 3 river systems in central and northern Queensland was examined. Eleven species were found, including 2 nematodes, 6 trematodes, 1 aspidogastrean, 1 cestode, and 1 monogenean. Analysis of helminth diversity showed that the Fitzroy and Ross River turtles had communities of comparable diversity, but the helminth communities in Proserpine River turtles were much less diverse. The helminth communities in all localities were dominated by trematodes. Polystomoides australiensis was the most prevalent, being found in 60% of the Ross River turtles, 57% of the Fitzroy River turtles, and 46% of the Proserpine River turtles. Notopronocephalus peekayi was the most abundant species, with mean abundances of 5.9 in the Ross River turtles and 9.8 in the Fitzroy River turtles. Species richness, Simpson's Reciprocal Index, was highest, 4.68, for the Ross River helminth community, Sorensen's Qualitative Index showed 95% similarity between the Ross River and Fitzroy River communities, although Sorensen's Quantitative Index indicated only 35% similarity between the 2 sites. Host feeding patterns are likely the most important factor affecting species richness of the helminth infracommunities, as the majority of helminth species are transmitted by food-web interactions involving intermediate hosts.     

The predictability of helminth community structure in space: a comparison of fish populations from adjacent lakes

Patterns in helminth community structure can suggest that various processes are acting to shape parasite communities into organised, non-random assemblages of species. It is not clear, however, whether a pattern observed in one host population at one time would be observed again at another time, or at the same time in a different but comparable host population. Here, we test the repeatability of parasite community structure in space, and to a lesser extent time, with data on helminth parasites of two fish species, perch Perca fluviatilis and roach Rutilus rutilus, collected in different seasons from four adjacent lakes in Central Finland. Since populations of the same fish species harbour the same parasite species and were sampled in the same way, we would expect similar patterns in the structure of their helminth parasites if the same structuring processes are acting in all lakes. We found that no pairwise association between the most common helminth species were observed consistently between seasons within lakes, or among lakes during the same season. Similarly, nested subset patterns of species assembly were observed in some samples, but not consistently between seasons or among lakes. The lack of repeatability in space and between seasons shown by these analyses indicates that although helminth community structure often departs from randomness, it does not do so in a consistent and predictable manner. There may be some general, large-scale processes acting to structure helminth communities, but local or seasonal influences can often either mask their action, or play more important roles themselves.     

Helminth parasites of the tropical gar, Atractosteus tropicus Gill, from Tabasco, Mexico

A total of 8 helminth species were recorded in an examination of 43 tropical gar, Atractosteus tropicus Gill, collected at the Pantanos de Centla Biosphere Reserve, Tabasco, Mexico. The parasite species included 1 adult trematode, 3 metacercariae, 1 cestode, 1 adult nematode, and 2 nematode larvae. Six of these 8 species were rare, with low prevalence (< 17%) and abundance (< 1.0 helminths per examined fish). The larvae of Contracaecum sp. were the most abundant in the sample, constituting 60% of the total helminths (64% prevalence, 3.8 +/- 5.2 abundance), followed by the cestode Proteocephalus singularis, constituting 18% of the worms (30.5% prevalence, 1.1 +/- 3.0 abundance). Species richness, individual parasite abundance, and diversity were low in the infracommunities. The recording of 3 specialist species in the tropical gar confirms that the helminth fauna of gar has an appreciable degree of specificity. This study indicates the importance of ecological determinants of richness in helminth communities of the tropical gar.