广东北江流域部分野生淡水鱼类种质资源调查

为了解广东省北江流域野生淡水鱼类种质资源和遗传多样性,于2007—2008年开展了广东省北江流域部分野生淡水鱼类的调查,运用线粒体DNA D-loop测序方法开展遗传多样性分析,测定采集鱼类的mtDNA D-loop基因序列并提交GenBank数据库,运用相关软件分析序列并建立聚类树。采集的野生淡水鱼类32种,隶属于3目10科27属,其中鲤形目鱼类21种,占65.6%,鲈形目鱼类4种,占12.5%,鲇形目鱼类7种,占21.9%。在鲤形目鱼类中,鳅科、平鳍鳅科、爬鳅科共12种,占鲤形目鱼类的57.1%。调查结果表明,北江流域存在丰富的野生淡水鱼类物种多样性,须采取有效措施保护北江流域淡水鱼类资源。测定的线粒体DNA D-loop序列均提交GenBank数据库获得序列号：EU380208-EU380236,EU697088-EU697148。测序结果和聚类树分析表明,线粒体DNA D-loop可作为鱼类种类鉴定的分子标记,分析结果印证了传统形态分类学的知识,提供了分子生物学证据。     

长江流域鱼类物种多样性大尺度格局研究

作者以长江流域鱼类编目数据库为基础数据,研究了长江流域鱼类物种多样性的大尺度格局。长江流域内共记录了鱼类378种(亚种),隶属于14目32科144属。其中淡水鱼338种(亚种),以鲤形目为主,达到269种(亚种),洄游鱼类11种,河口鱼类29种;流域内特有种和受威胁物种分别有162种(亚种)和69种(亚种)。根据鱼类分布特点,按水系将长江流域分为19个区域,除了江源区和金沙江中上游外,物种数和G-F多样性指数上游高于中下游,但各区域内差异不大,然而特有种比例从上游到下游随海拔降低而逐渐降低。利用Jaccard物种相似性系数对19个区域进行聚类分析,将整个流域分成三部分:(1)江源区和金沙江中上游,地理上属于青藏高原东南部波状平原部分和横断山区,(2)上游其他流域,地理上属于川西高原、云贵高原、四川盆地及秦巴山区,(3)中下游流域,地理上属于淮阳山地、江南丘陵和长江中下游平原,基本反映了流域内自然地理环境及我国大陆地势三级台阶变化的特点。     

赣江鱼类物种更新名录

赣江是长江的主要支流之一, 淡水鱼类多样性极其丰富, 但是目前对于该河流的鱼类多样性还未有充分的了解。本研究于2016年9月至2017年8月对赣江鱼类进行了实地调查, 结合历史文献资料并参考最新的分类学成果, 更新了赣江淡水鱼类名录。结果表明, 赣江共有淡水鱼类180种, 隶属于12目31科93属。其中, 土著鱼类174种, 外来鱼类6种。赣江鱼类以鲤形目为主; 鲤科种类最多, 其次是鲿科。更新的物种名录中, 包含23个新记录土著种, 其中有5个未被描述的新种; 有36个历史资料记载的种类被剔除出物种名录; 25个物种发生了分类地位的变更。此外, 本次调查有28种鱼类未采集到, 说明这些鱼类的种群数量正在急剧下降, 而这些鱼类分别属于洄游性、流水性和产漂流性卵等独特生态类型, 说明赣江鱼类多样性受到了严重的人为干扰。本研究所给出的赣江鱼类的更新物种名录, 可为今后的赣江鱼类多样性保护提供理论基础。     

跨流域调水背景下汉江流域洋县段的鱼类多样性及资源现状

汉江是南水北调中线工程和引汉济渭等跨流域调水工程重要的水源区, 了解其鱼类多样性的现状及变化对于水生态保护尤为重要。作者于2016-2017年间对汉江洋县段干流与6条主要支流的鱼类多样性组成进行了两次调查, 以Margalef丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数和Jaccard相似性系数对洋县境内7条河流进行评估, 同时通过相对重要性指数(index of relative importance,IRI)判定优势种, 利用鱼类丰度生物量(abundance biomass comparison, ABC)曲线分析鱼类受干扰情况。结合历史记录, 调查区域内共分布有土著鱼类76种, 隶属于6目14科57属, 以鲤形目鲤科和鲇形目鲿科鱼类为主, 分别占土著鱼类总数的57.89%和11.84%; 珍稀濒危鱼类共计5种, 包括3种国家级保护水生野生动物。鱼类多样性分析结果显示汉江干流的丰富度指数和多样性指数显著高于6条支流。7条河流的IRI指数显示优势种为宽鳍鱲(Zacco platypus)。ABC曲线显示目前调查区域内鱼类小型化现象明显、鱼类受到较严重干扰。水利水电工程建设对于调查区域鱼类多样性影响最大, 干流大型水库(大坝)通过改变原有流水生境、阻断河流纵向连通性、淹没重要鱼类产卵场等对鱼类多样性和群落组成产生不利影响; 支流引水式的中小型电站造成下游河段减、脱水而使河道发生断流以及生境破碎化, 从而威胁土著鱼类的生存。在跨流域调水过程中, 应重视不同水系鱼类引入的潜在生态风险。对引汉济渭工程的水源区鱼类多样性现状的调查, 有助于未来跨流域调水过程中鱼类变化的动态监测和外来物种的预警。     

海南岛陵水河流域淡水鱼类群落结构及历史变化研究

根据2019年4月至2021年3月的调查数据,对海南岛陵水河流域淡水鱼类群落结构、多样性及其历史变化进行了研究。共调查到鱼类47种,隶属于6目19科,其中海南特有种7种,陵水河流域历史未记录种21种。鲤形目（Cypriniformes）鱼类种类最多,为23种,占物种总数的49%。Shannon-Wiener多样性指数（H′）为3.12、物种丰富度（D）为6.10、均匀度指数（J''）为0.81、优势度（λ）为0.06。与历史资料相比陵水河流域土著鱼类缺失种类达16种,其中受威胁鱼类种类锐减明显,同时外来鱼类种类显著增加。本研究结果为陵水河流域淡水鱼类多样性保护策略制定提供科技支撑,同时为海南省热带淡水鱼类多样性保护研究积累基础数据。     

黄河流域淡水鱼类多样性和保护

本文介绍了黄河流域鱼类研究的历史、淡水鱼类的物种组成、整体分布格局、特有性、濒危性, 以及鱼类多样性在黄河上、中、下游等的特点。历史上对于黄河鱼类多样性的研究, 历经了四个阶段, 从最初的零星记录一直到现阶段的深入研究。综合历史记录和野外调查, 已知黄河流域分布的淡水鱼类共计147种, 隶属于12目21科78属, 其中鲤形目种类占据绝对优势。另外, 全流域黄河特有种计有27种, 受危物种24种, 分别占总数的18.37%和16.32%。同中国主要江河相比, 黄河鱼类在高级分类阶元上的多样性较高, 但物种多样性则处在较低水平; 尽管黄河特有鱼类和受危物种比例低于全国平均水平, 但上游特有鱼类和珍稀濒危鱼类的占比很高。目前黄河鱼类多样性大幅降低, 现状调查仅能采获历史记录种类的53.06%。梯级水电开发、水资源过度利用、外来物种、水域污染和过度捕捞都是威胁鱼类多样性的重要因素, 但对各河段和支流的影响不一, 应做出有针对性的保护部署。     

2011年第3期《遗传》封面说明

老挝纹胸鮡(Glyptothorax laosensis),俗名又称石扁鱼、石扁头、石贴子、老虎鱼、刺古头,隶属鲇形目(Siluriformes)、鮡科(Sisoridae)、纹胸鮡属(Glyptothorax),分布于我国云南以及泰国、老挝、缅甸、柬埔寨、越南的澜沧江-湄公河流域,模式产地在泰国湄公河。老挝纹胸鮡为澜沧江-湄公河流域特有鱼类。     

怒江流域鱼类多样性及空间分布格局

怒江是我国西南地区重要的国际河流, 也是全球生物多样性热点区域之一。受地理位置和地形条件限制, 目前尚缺乏怒江流域鱼类物种多样性及其分布格局的系统研究。本研究利用近5年的全流域实地采样数据, 结合文献资料, 系统整理了怒江流域鱼类物种组成信息; 利用聚类和排序方法分析了怒江流域鱼类空间分布格局。结果表明, 怒江流域共有土著鱼类85种, 隶属于5目12科47属; 外来鱼类18种, 隶属于3目8科16属, 另外实地调查发现新记录外来种2种。怒江流域鱼类多样性从上游至下游呈明显的递增趋势。根据土著鱼类组成的聚类和排序分析结果, 可以将怒江25个亚流域分为3个部分: (1)西藏自治区内的上游河段, 分布有鱼类15种, 组成以裂腹鱼类、高原鳅类为主, 具有明显青藏高原冷水性鱼类区系特征。(2)贡山至泸水的中游河段, 分布有鱼类36种, 组成兼有上游冷水性鱼类和下游喜温的鲃亚科、野鲮亚科鱼类。(3)泸水以下的下游河段, 分布有鱼类74种。下游河段干流广泛分布有喜温的鲃亚科、野鲮亚科和 亚科鱼类, 支流则分布有数量众多的南鳅属(Schistura)、纹胸鮡属(Glyptothorax)鱼类, 鱼类组成以适应流水、激流环境的热带亚热带鱼类为主。2017-2021年的多次调查仅发现土著鱼类43种(占历史记录的50.6%), 土著鱼类资源衰退明显。过度捕捞、支流小水电开发、外来鱼类入侵等是主要威胁因素。随着人类活动的急剧增多, 怒江流域鱼类将面临更大的威胁, 亟需从流域层面开展系统的鱼类资源管理和保护规划。     

中国新石器时代以来淡水及河口鱼类考古遗存的地理分布及其生物地理学意义

考古遗址中出土的鱼类遗存是探讨现生种类在历史时期的地理分布的重要资料。本文系统整理了中国新石器时代至明代考古遗址中出土的淡水及河口鱼类考古遗存记录, 对比了鉴定至物种的遗存记录分布与现状分布, 探讨了个别物种古今分布变迁的可能成因。结果显示: (1)目前中国淡水及河口鱼类考古遗存共鉴定记录了72个类群, 分属于8目12科, 其中以鲤形目的类群数量最多(43); 鉴定至物种的共42种, 其中以鲤(Cyprinus carpio)和青鱼(Mylopharyngodon piceus)的出土遗址(群)数量最多(各46个)。(2)有淡水及河口鱼类遗存出土记录的遗址中, 属新石器时代的遗址(群)数量最多(68), 从这些遗址(群)中出土鉴定的类群数(60)也在各时期中居于首位。(3)淡水及河口鱼类遗存鉴定记录的类群最多的流域是长江流域(55个), 其次为淮河流域(24个)和黑龙江流域(22个); 而南海流域、西南流域和台湾岛流域各仅有1个类群。(4)有8个物种在其现存自然分布范围以外的流域至少有1处遗存鉴定记录: 团头鲂(Megalobrama amblycephala)、须鲫(Carassioides acuminatus)、龙州鲤(Cyprinus longzhouensis)、鳙(Aristichthys nobilis)、草鱼(Ctenopharyngodon idella)、青鱼、黄鳝(Monopterus albus)和日本花鲈(Lateolabrax japonicas); 除草鱼和青鱼之外, 其余6种在其各自现存分布区以北的流域至少有1处遗存记录。研究结果表明, 中国新石器时代以来的淡水及河口鱼类考古遗存记录所展现的区系地理格局整体上与现今格局一致。个别物种在历史时期的分布较现今分布区范围更广, 这可能是因为遗存出土地区的古气候普遍较现今温暖, 亦或是因其后气候变化或水系变迁使部分鱼类的分布区变狭窄。     

江西赣江源自然保护区鱼类物种多样性初步研究

江西赣江源自然保护区地处武夷山脉南端.2007年11月和2008年5月,对保护区鱼类资源进行实地调查.调查发现保护区内野生淡水鱼类共计16种,隶属于4目8科15属,以鲤形目鲤科鱼类为主,多为山区溪流小型鱼类.鱼类物种多样性在空间分布上有所不同,低海拔处鱼类种类较高海拔处丰富;其多样性在时间上夏季高于冬季.     

Effects of damming on the biological integrity of fish assemblages in the middle Lancang-Mekong River basin

The Lancang-Mekong River basin contains a diverse assemblage of freshwater fish species; however, their populations are threatened by current and planned dam construction along the river. Fish assemblages are sensitive indicators of environmental degradation and can be used to assess aquatic ecosystem health. This research compared the fish fauna at the Xiaowan hydropower dam located on the middle reaches of the Lancang-Mekong River at three time periods: in 2008 (before impoundment), 2010 (water storage) and 2011 (full operation). A modified fish index of biological integrity (modified F-IBI) was developed and it synthesized information on the taxonomic composition, trophic guilds, and tolerance levels of the fish and habitat diversity to quantitatively assess the condition of fish populations before and after damming. This index also was used to assess the longitudinal diversity of the fish fauna along the river channel and could assess the barrier effect associated with the dam. Jaccard's index of similarity was used as a feasible tool to assess fish diversity loss and biotic homogenization. The analysis clearly showed a homogenization of the fish communities after damming, and the reservoir impoundment region showed much more serious homogenization than the downstream region. The Xiaowan dam had an immediate and profound effect on the fish fauna in this region of the Lancang-Mekong River. A total of eight cascading dams are planned for development in this region, and, unless conservation mitigation efforts are considered, the results could be devastating on the native fish populations of middle reaches of the Lancang-Mekong River basin.     

Freshwater fish biodiversity in the Yangtze River basin of China: patterns, threats and conservation

We synthesized information on freshwater fish biodiversity in the Yangtze River basin. We documented 361 species and subspecies that had been recorded and described from the basin. Of these, 177 species are endemic. The basin is usually divided into three parts, i.e. the upper reaches, the middle reaches and the lower reaches. This study indicated that the three reaches approach was not supported by fish distribution patterns. Hydrological alterations are perhaps the largest threat to fish biodiversity in the basin. Fishes in the upper reaches will be seriously affected by the construction of the Three Gorges Dam and other dams, and action should be taken for priority conservation. The most immediate restoration need is reconnection of the Yangtze River with its lakes. The cluster of lakes in the Central Yangtze should be protected to maintain habitats for spawning, feeding and migration of migratory fishes. Our study indicates a need to identify areas of high fish biodiversity and to select nature reserves to mitigate the loss of fish biodiversity in the Yangtze River basin.     

Distribution pattern, threats and conservation of fish biodiversity in the East Tiaoxi, China

East Tiaoxi River is one of the largest inflowing rivers into Taihu Lake, and the fish fauna in the river is poorly understood. In the present study, an extensive survey of fish was conducted in October and November 2009, May and September 2010 and May 2011 covering a total of 55 sites along the whole river. A total of 84 freshwater fish species belonging to 8 orders, 18 families and 52 genera have been recorded. Among these are 35 species endemic to China, and 3 newly recorded exotic species. The fish composition varies greatly from headwaters to downstream. Based on cluster analysis with presence-absence data, the East Tiaoxi River is divided into four regions, specifically, the upper reach, middle-up reach, middle reach and lower reach. It is observed that species richness and the proportion of omnivorous species increased from upstream to downstream while the proportion of invertivorous species decreased consequently. Habitat alteration, overfishing, pollution and inland navigation adversely affect the fish diversity and ecosystem functioning in the East Tiaoxi River. To protect fish diversity more effectively in the area, the conservation of fish biodiversity in the North Tiaoxi River and Middle Tiaoxi River should be considered as a priority. Meanwhile, shallow zones or backwater areas should be created in the middle-lower reaches. Furthermore, river restoration, in terms of habitat creation, should be considered to protect the structure and diversity of fish communities, halt the progressive deterioration of freshwater ecosystems and sustain a valuable ecological resource for humans.     

Downstream migration of juvenile fish in the Krasnaya River (Vietnam)

The first material is presented on downstream migration of fish juveniles in the Krasnaya River, one of the largest rivers in South-East Asia. The spatial-temporal structure of distribution of downstream-migrating fish juveniles in the Krasnaya River has traits usually characteristic of migration in rovers with turbid water. Concentration of fish was extremely variable by the time of the day, river length, and depth. In length-wise distribution, there was a tendency to increasing concentration of downstream migrants from the upper stretches to the downstream stretch. In the upper reaches, Perciformes prevailed, in the middle part, Cypriniformes prevailed, and in the lower reaches of the river Clupeiformes prevailed. During 24 h, Clupeiformes and Perciformes migrated more intensively at night and Cypriniformes migrated more in the daytime. By depth horizons, Clupeiformes made downstream migration predominantly at the surface and Cypriniformes and Perciformes did at the bottom. These differences may be caused by species differences in fish biology, local specific traits of stream hydraulics, anthropogenous factors, etc.     

长江流域两栖动物物种多样性的大尺度格局

根据两栖动物分布依赖于水系的特点,依据主要水系将长江流域分为18个区域,共记录了两栖动物145种,隶属于2目10科30属,特有种和受威胁物种分别有49和69种。除了海拔最高的江源区和金沙江中上游流域外,两栖动物种类以及受威胁物种种类,从上游到下游逐渐降低,特有种比例同样从上游到下游随海拔降低逐渐降低;分析G-F多样性指数发现,G指数的分布与物种数分布规律相似,F指数与G-F指数相似,除了江源区、汉江和赣江较低外,其他区域内比较均匀。利用Jaccard物种相似性系数对流域内18个区域进行聚类分析,发现整个流域分成6部分江源区,横断山区,云贵高原,川西高原东缘、四川盆地和秦巴山区,洞庭湖水系、鄱阳湖流域和下游流域,以及赣江流域,基本反映了长江流域内自然地理环境及我国大陆地势三级台阶变化的特点。     

Fish taxonomic,functional, and phylogenetic diversity and their vulnerabilities in the largest river in southeastern China

1. Freshwater biodiversity is currently under multiple threats. Conservation of freshwater fish biodiversity needs to be prioritized because natural conservation resources are always limited.
2. Samples were collected at 24 sites in the Min River, the largest basin in southeastern China. Taxonomic, functional, and phylogenetic diversity were analyzed. Biodiversity vulnerability was measured by removing one species each time out of the community with replacement.
3. Results suggested that hotspots for taxonomic and phylogenetic diversity were located at two impounded sites, while for functional diversity were those sites with no upstream dams. Little congruence was observed between taxonomic, functional, and phylogenetic diversity. Fragmentation of river network connectivity caused by dams was a significant factor affecting the biodiversity patterns. Beta turnover was the driving component for beta diversity, indicating that biodiversity dissimilarity along the river was mostly explained by environmental sorting. Fifteen out of 16 species that contributed the most to different facets of biodiversity were mostly endemic, either they had distinctive functional traits or they were the most prevalent species. Sites with the highest diversity vulnerability were characterized by these distinctive species. Functional diversity was more vulnerable to species loss comparing with the other two biodiversity facets.
4. Prioritizing those biodiversity hotspots, sites with extreme functional vulnerability, and those distinctive endemic species which contributed the most to biodiversity vulnerability is suggested in the Min River. The study found evidence that congruence among different facets of biodiversity is hard to achieve, and functional diversity is the most vulnerable in a freshwater system fragmented by intensive dam constructions. This work will help to develop systematic conservation planning from the perspective of different biodiversity facets.