黄山陈村水库上游河源溪流的鱼类群落及其纵向梯度格局

确定鱼类群落的分布格局及其对人类活动的响应,是合理保护、恢复和管理鱼类多样性的基础。基于2011年5月和10月自黄山陈村水库上游3条河源溪流共39个样点的调查数据,比较研究了溪流间鱼类群落及其纵向梯度格局的异同,着重探讨了人类活动对溪流鱼类群落纵向梯度格局的影响。研究结果显示,同人为干扰较轻的舒溪相比,人为干扰严重的浦溪和麻溪中水宽、底质和植被覆盖率等局域栖息地条件显著变化,这造成了后者的鱼类多样性显著下降及物种组成的显著变化,主要表现为敏感性的地方物种(如宽鳍鱲、光唇鱼、原缨口鳅等)数量减少、耐受性的广布物种(如泥鳅、麦穗鱼、高体鰟鲏等)数量增多。舒溪的鱼类物种数及其组成均与海拔显著相关,但这种"海拔-鱼类群落"关系在麻溪和浦溪中削弱甚至消失。底质、植被覆盖率对舒溪鱼类群落具有重要影响,但对浦溪和麻溪鱼类群落却无显著影响。研究结果表明,在子流域空间尺度上,诸如城镇化发展、土地利用、河道治理等人类活动可通过对局域栖息地条件的影响,导致溪流鱼类多样性下降及其物种组成的变化,破坏鱼类群落的纵向梯度格局,并改变栖息地与鱼类群落之间的联系。     

黄山陈村水库河源溪流鱼类群落的食性

基于2010年11月在黄山陈村水库河源溪流中所采集的鱼类标本,对其中9种优势鱼类的食性特征进行了研究。结果表明:宽鳍鱲(Zacco platypus)、光唇鱼(Acrossocheilus fasciatus)和麦穗鱼(Pseudorasbora parva)等9种鱼类都以有机碎屑、藻类和无脊椎动物为主要食物,属典型的杂食性或无脊椎动物食性鱼类;食物组成的相似性分析结果表明,不同物种间的食物组成差异显著但存在部分重叠(P<0.001)。不同物种间的食物多样性和食性宽度也存在显著性差异(P<0.05),其中底栖型鱼类具有相对较高的饵料来源,而鱼类的食物多样性可能与其小生境选择性有关。根据食物重叠指数,9种优势鱼类之间存在明显的食物重叠(D>0.3),尤其是宽鳍鱲、光唇鱼、麦穗鱼、高体鰟鮍(Rhodeus ocellatus)和稀有花鳅(Cobitis sinensis)间的食物重叠指数超过0.9。陈村水库河源溪流的鱼类群落所表现出的食物组成、食物多样性、食性宽度和种间食物重叠性等特征,可能与其生态系统所具有的营养外源性和物理栖息地周期动荡性等密切相关。     

三峡水库香溪河鱼类资源现状及渔业管理建议

于20122013 年对香溪河鱼类组成及资源量进行了周年季度调查, 结合历史资料, 分析了三峡水库成库前后香溪河鱼类资源的变动情况, 以期为保护和利用三峡库区的鱼类资源提供依据。共采集鱼类48 种,隶属于 3 目 8 科 35 属, 以湖泊定居性鱼类为主;发现香溪河鱼类优势种是光泽黄颡鱼、鳙、鲢、达氏鲌、贝氏 、大眼鳜、翘嘴鲌、瓦氏黄颡鱼、银 、蛇;肉食性鱼类(达氏鲌、翘嘴鲌、大眼鳜等)占总渔获量的31.54%, 生物量相对较高;对单位捕捞努力渔获量的调查显示, 夏季日均单船渔获量最高, 达到(69.4546.61) kg/(船d)。与历史记录比较, 三峡水库成库后, 香溪河的鱼类群落组成已经发生了显著变化,湖泊定居性鱼类成为优势种群。基于此次调查结果, 文章提出了禁渔期调整、小型鱼类资源利用和肉食性鱼类合理放养等渔业管理建议。       

秋浦河源国家湿地公园溪流鱼类群落的时空格局

确定溪流鱼类群落的时空格局及其形成机制是开展鱼类物种多样性保护和管理的科学基础。该文于2012年5月和10月两次对秋浦河源国家湿地公园境内的24个可涉水河段取样,共采集鱼类29种,隶属10科4目。研究了溪流鱼类群落结构及其多样性的时空格局,并解析了局域栖息地条件与支流空间位置变量对鱼类群落的影响。鱼类多样性的时空变化显著,鱼类多样性总体上为二级溪流高于一级溪流,10月份高于5月份。流量量级、底质粗糙度及异质性、水温和水深等对鱼类多样性及群落结构的空间变化影响显著。鱼类群落结构符合嵌套格局,季节动态不显著,上游鱼类群落呈现为下游群落的嵌套子集。一、二级溪流间的群落结构尽管存在部分重叠但差异显著,且这种差异主要源于稀有花鳅(Cobitis rarus)、吻虾虎鱼(Ctenogobius spp.)、宽鳍鱲(Zacco platypus)、尖头鱥(Phoxinus oxycephalus)、高体鰟鲏(Rhodeus ocellatus)和原缨口鳅(Vanmanenia stenosoma)等鱼类相对多度的空间变化,其中,除尖头鱥的多度在一级溪流中更高外,其他5种鱼类均在在二级溪流更高。     

中国吻虾虎鱼属一新种：鲈形目：虾虎鱼科

在浙江省灵江水系上游横溪镇附近溪流中,采到１种吻虾虎鱼属鱼类,经鉴定为１新种。根据该种鱼类颊部具１－４条明显的细斜纹,定名为颊纹吻虾虎鱼Ｒｈｉｎｏｇｏｂｉｕｓ ｇｅｎａｎｅｍａｔｕｓ Ｚｈｏｎｇ ｅｔ Ｔｚｅｎｇ ｓｐ．ｎｏｖ．     

人为干扰对溪流鱼类功能多样性及其纵向梯度格局的影响

溪流鱼类多样性沿着河流纵向梯度的空间分布规律已得到大量报道, 但这些研究大多聚焦基于物种组成的分类α多样性, 而有关分类β多样性和功能多样性的纵向梯度分布规律及其对人类干扰的响应研究较少。本文以青弋江上游3条人为干扰程度不同的河源溪流为研究区域, 比较研究了人为干扰对溪流鱼类功能α和β多样性及其纵向梯度分布格局的影响。结果显示, 人类干扰改变了河源溪流鱼类功能多样性的纵向梯度格局——由线性变化变为二项式分布。此外, 我们发现, 人为干扰导致土著种被本地入侵种取代, 且较强的土地利用和水污染排放可能增大环境的不连续性, 而群落周转和嵌套变化往往取决于环境的变化。尽管功能β多样性由嵌套成分主导, 但周转成分占比相对于人为干扰较小的溪流而言明显增加。人为干扰显著改变了受干扰溪流鱼类的物种组成和功能多样性, 且功能多样性的纵向梯度格局在不同的多样性指标上存在差异。本研究强调, 在评估人为干扰下多样性的变化时, 需要从多方面考虑, 包括空间尺度和多样性指标等。     

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。     

溪流大小及其空间位置对鱼类群落结构的影响

2008年10月和2009年10月分别对黄山地区阊江流域与青弋江流域1-3级浅水溪流中鱼类群落结构进行了研究,着重探讨了溪流大小及其空间位置对鱼类群落空间分布的影响。研究共捕获35种鱼类,阊江和青弋江分别为26和29种,其Jaccard相似性系数为57.1%;两流域间每样点的物种数差异显著,个体数差异极显著。在溪流级别梯度(1-3级)下,鱼类的物种数和个体数都呈上升的变动趋势,且物种数的变化相对个体数较显著。综合相关分析、逐步多元回归分析与典范相关分析的结果,阊江和青弋江中鱼类物种数的空间变化主要与下游量级相关,而个体数的空间变化主要与水宽相关。因此,阊江和青弋江1-3级浅水溪流中鱼类群落结构的空间分布格局是溪流大小和空间位置的共同作用结果,且溪流大小和空间位置分别决定鱼类的个体数与物种数的空间分布。       

滇池土著鱼类现状

于2000年4月－12月对滇池区域的土著鱼类进行调查发现,滇池土著鱼类由20世纪60年代的26种减少到目前的11种,这11种滇池土著鱼类中,仅有4种生活于滇池湖体,其余7种均生活于滇池湖周一些溪流的上游或溶洞中,通过对土著鱼类及其栖息地的实地调查并结合文献资料,分析了滇池土著鱼类多样性的历史变化,各种类在空间上的变化方式以及滇池土著鱼类多样性迅速降低的原因,并就保护滇池土著鱼类提出具体的解决方法和途径。     

低头坝驱动山区溪流局域栖息地和鱼类群落的同质化

确定溪流鱼类多样性对环境变化和人类干扰的响应,可为溪流生态系统及鱼类多样性的保护和管理提供科学基础。本文基于对安徽省青弋江流域上游的4条一级河源溪流中39个低头坝、78个调查样点(针对每个低头坝所处河段,分别设置坝上蓄水区(impounding area)和坝下非蓄水区(free-flowing area)各1个调查样点)的调查数据,研究了低头坝对局域栖息地和鱼类群落同质化的驱动作用。共采集鱼类27种,隶属5目10科,其中蓄水区和非蓄水区的物种分别为23种和27种。主坐标分析和主坐标典范分析结果显示,蓄水区与非蓄水区间的局域栖息地存在显著差异,同非蓄水区相比,蓄水区的底质粗糙度和异质性较小但水深和水宽较大;置换多元分散分析结果显示,蓄水区局域栖息地特征的空间变异显著低于非蓄水区,呈现出明显的同质化现象。以非蓄水区为对照,蓄水区鱼类群落的相似性在研究的4条溪流、2个不同季度呈现出相似的变化趋势,即:一些鱼类群落间的相似性上升但另外一些群落间的相似性下降,且其相似性变化大小(ΔCS_J)与初始相似性显著负相关;当初始相似性较低时,ΔCS_J0;当初始相似性较高时,ΔCS_J0。本研究表明,低头坝导致了坝上蓄水区局域栖息地特征空间变异的下降,呈现出明显的栖息地同质化;但蓄水区鱼类群落同时存在同质化和异质化2个过程,群落间初始相似性大小决定了其同质化或异质化:初始相似性较低呈同质化、较高则异质化。     

Spatial and temporal variation of fish assemblages in a subtropical small stream of the Huangshan Mountain

Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities (...     

皖南凹耳臭蛙地理分布格局与生境选择

凹耳臭蛙(Odorrana tormota)是一种小型山溪蛙类,由于叫声独特,种内具有超声通讯功能而引起国内外相关专家的广泛关注。首次针对皖南凹耳臭蛙地理分布、生境选择以及人为干扰强度对种群密度的影响进行了研究。共调查了9县1区32条不同的山溪,发现其中的16个有凹耳臭蛙分布,除黄山区的香溪和浮溪具文献记录外,其余14个分布点均为首次报道。基于现存凹耳臭蛙分布点的水系关系,推测该物种在皖南的分布呈现出以青弋江、新安江和水阳江三大水系为纽带、间断分布的格局。对其中10个分布点222只凹耳臭蛙生境选择的统计结果表明,在夜晚活动周期内,该物种对乔木、灌木丛、草本植物、岩石、沙滩和倒伏朽木等不同生境的选择具有显著差异(F5,54=25.75,P0.001),栖息在草本植物和灌丛中蛙的数量明显多于栖息在其它几种生境类型中的蛙类。暗示溪流沿岸的草本植物和灌丛对该物种的生存和繁衍具有重要意义,乔木对其非活动周期的隐蔽可能具有不可替代的作用。根据人类活动对其栖息地破坏程度,将人为干扰程度划分为强、中和弱3种不同强度,对不同干扰强度下种群相对密度进行单因素方差分析。结果表明,中等干扰强度下的种群密度显著高于其它两种强度下的种群密度(F2,13=8.155,P=0.005)。推测适度的人为干扰可能增加了栖息地内昆虫的种类和数量,对蛙类的生存和繁衍更为有利。但随着人为干扰强度的增强,对溪流沿岸植被的破坏更为剧烈,种群密度显著下降。     

Shifts in zooplankton communities in high-mountain lakes induced by singular events (fish stocking,earthquakes): evidence from a 20-year survey in Slovenia (Central Europe)

Thirteen mountain lakes, originally fishless, at 1325 and 2150 m a.s.l., with the maximum depths ranging from two to 15 m, and areas of 0.3 to 4.5 ha, were monitored between 1991 and 2012 in the Triglav National Park (Slovenia, Central Europe). The lakes are located on limestone bedrock, with no surface inflow or outflow. They range from ultra-oligotrophic to hypertrophic. They were stocked with fish between late 1920s and 1996. The zooplankton samples were collected as composites from the bottom to the surface at the deepest point of the lake, for both qualitative and quantitative analyses. In situ physical parameters in the water column were measured, and the samples for chemical analyses were collected in parallel with the zooplankton sampling. Thirty-two species, including Copepoda, Cladocera, Rotifera and Ciliata, were recorded. They belonged to three ecological groups: (1) constitutive, (2) scout and (3) benthic species. In some of the lakes, the species composition remained stable over the study period, but in lakes stocked with fish, significant changes occurred, in both species composition and biomass. Large-bodied species of Copepoda and Cladocera were eliminated by fish allowing small-bodied planktonic species of Copepoda, Cladocera and Rotifera to dominate the community, along with benthic species, associated with algal mats. The lake, stocked with fish in the 1920s, was hit by two strong consecutive earthquakes, in 1998 and 2004, after which a significant change in species composition and biomass was recorded.

     

Eradication of Nonnative Fish by Gill Netting from a Small Mountain Lake in California

Nearly all mountain lakes in the western United States were historically fishless, but most now contain introduced trout populations. As a result of the impacts of these introductions on ecosystem structure and function, there is increasing interest in restoring some lakes to a fishless condition. To date, however, the only effective method of fish eradication is the application of rotenone, a pesticide that is also toxic to nontarget native species. The objective of this study was to assess the effectiveness of intensive gill netting in eradicating the trout population from a small subalpine lake in the Sierra Nevada, California. We removed the resident trout population and a second trout population accidentally stocked into the study lake within 18 and 15 gill net sets, respectively. Adult trout were highly vulnerable to gill nets, but younger fish were not readily captured until they reached approximately 110 mm. To determine the utility of gill netting as a fish eradication technique in other Sierra Nevada lakes, we used morphometry data from 330 Sierra Nevada lakes to determine what proportion had characteristics similar to the study lake (i.e., small, isolated lakes with little spawning habitat). We estimated that gill netting would be a viable eradication method in 15–20% of the high mountain lakes in the Sierra Nevada. We conclude that although gill netting is likely to be more expensive and time consuming than rotenone application, it is a viable alternative under some conditions and should be the method of choice when sensitive native species are present.     

基于水声学探测的香溪河鱼类资源时空分布特征评估

为了掌握三峡水库香溪河鱼类资源时空分布特征, 2013 年5 月和11 月运用Simrad EY60 型分裂波束回声探测仪在香溪河进行了水声学探测, 辅以常规渔获物分析方法。渔获物调查共发现鱼类7 科41 种, 其中似鳊、贝氏、、银和蛇等小型鱼类在数量上占据优势地位。水声学探测结果表明, 香溪河春季鱼类密度显著高于秋季, 采用加权平均法求得2013 年5 月和11 月探测的鱼类密度分别为53.4 和15.4 ind./1000 m3。鱼类资源在空间上不均匀分布, 从高岚河至香溪河口鱼类密度逐渐降低;在垂直方向上, 春季和秋季水声学探测的鱼类密度显示出相同的趋势, 即表层 中层 底层。在运用鱼类生物操纵改善水质途径方面, 建议通过壮大肉食性鱼类种群来控制小型鱼类资源量, 同时通过增殖放流鲢、鳙以加强对浮游植物的滤食作用。       

Trophic consequences of non‐native species for commercial fish in a backwater bay of the Three Gorges Reservoir,Southwest China

Trophic niche overlap in native and alien fish species can lead to competitive interactions whereby non‐native fishes outcompete indigenous individuals and eventually affect the viability of natural populations. The species Erythroculter mongolicus and Erythroculter ilishaeformis (belonging to the Culterinae), which are two commercially important fish species in the backwater bay of the Pengxi River in the Three Gorges Reservoir (TGR), were threatened by competition from the non‐native Coilia ectenes (lake anchovy). The latter is an alien species introduced into the lower reaches of the Yangtze River in China and now widespread in the TGR. The trophic consequences of non‐native lake anchovy invasion for E. mongolicus and E. ilishaeformis were assessed using stable isotope analysis (δ¹³C and δ¹⁵N) and associated metrics including the isotopic niche, measured as the standard ellipse area. The trophic niche of native E. mongolicus had little overlap (<15%) with the alien fish species and was significantly reduced in size after invasion by lake anchovy. This suggests that E. mongolicus shifted to a more specialized diet after invasion by lake anchovy. In contrast, the trophic niche overlap of native fish E. ilishaeformis with the alien fish species was larger (>50%) and the niche was obviously increased, implying that fish in this species exploited a wider dietary base to maintain their energetic requirements. Thus, marked changes for the native E. mongolicus and E. ilishaeformis were detected as the trophic consequences of invasion of non‐native lake anchovy.     

洪湖鱼类多样性研究

根据1992～1993年洪湖鱼类资源调查,结合1959年和1982年的历史资料,分析了洪湖鱼类物种多样性和群落结构多样性的变化。结果表明,洪湖鱼类从江湖阻隔初期的湖泊定居性鱼类为主、江湖洄游性鱼类和少数河海洄游性鱼类亦有一定的产量、大型和中型鱼类占较大比例,逐渐演变成以鲫占绝大多数的“众小”局面;鱼类群落的营养结构从草食性种类的比例高达23%～35%、肉食性种类比例波动于10%～20%之间,逐渐演变成以鲫为主的杂食性鱼类占绝大多数,草食性种类基本上从湖内消失;种类组成从阻隔前的推测应不下100种演变成50余种,且实际能在洪湖生息的只有30余种;多样性指数、均匀度指数均有不同程度的降低。     

Phylogeny and historical demography of endemic fishes in Lake Biwa: the ancient lake as a promoter of evolution and diversification of freshwater fishes in western Japan

To elucidate the origins of the endemic fish of Lake Biwa, an ancient lake in Japan, and the role of the lake in the diversification of freshwater fish in western Japan, we established a molecular phylogenetic framework with an absolute time scale and inferred the historical demography of a large set of fish species in and around the lake. We used mtDNA sequences obtained from a total of 190 specimens, including 11 endemic species of Lake Biwa and their related species, for phylogenetic analyses with divergence time estimations and from a total of 2319 specimens of 42 species (including 14 endemics) occurring in the lake for population genetic analyses. Phylogenetic analysis suggested that some of the endemic species diverged from their closest relatives earlier (1.3–13.0 Ma) than the period in which the present environmental characteristics of the lake started to develop (ca. 0.4 Ma), whereas others diverged more recently (after 0.4 Ma). In contrast, historical demographic parameters suggested that almost all species, including endemic and nonendemic ones, expanded their populations after the development of the present lake environment. In phylogeographic analyses, common or very close haplotypes of some species were obtained from Lake Biwa and other regions of western Japan. The phylogenetic and historical demographic evidence suggests that there was a time lag between phylogenetic divergence and population establishment and that phenotypic adaptation of some endemic species to the limnetic environment occurred much later than the divergences of those endemic lineages. Population structure and phylogeographic patterns suggest that Lake Biwa has functioned not only as the center of adaptive evolution but also as a reservoir for fish diversity in western Japan.     

A New Species of the Genus Achalinus from Huangshan,Anhui, China(Squamata: Xenodermidae)

A new species of the genus Achalinus is described based on five specimens collected from the villages of Huangjialing and Fuxi, Huangshan, Anhui, China. It can be morphologically differentia ted from all the other species in Achalinus except for A. spinalis and A. werneri by the presence of a dotted black streak in the middle of the subcaudal. It can be distinguished from A. spinalis in that its two anterior temporals are in contact with eye, and A. werneri by its light brown flanks. The phylogenetic rela tionship of Achalinus was reconstructed using the mitochondrial locus of cytochrome coxidase subunit 1(CO1). The five new specimens form a monophyletic clade with strong support. The uncorrected p-dista nces between the new species and other representatives of Achalinus range from 13.6% to 21.7%. The recognition of the new species increases the number of described Achalinus species to 14.