西藏湿地外来麦穗鱼生活史特征的适应性研究

研究于2019—2021年对青藏高原拉鲁湿地和茶巴朗湿地的外来麦穗鱼进行了实地调查和样品收集, 对其种群年龄、生长和繁殖等生活史特征进行了分析, 并通过与南京及我国其他低海拔地区的原产地种群的对比分析, 探讨了麦穗鱼对高原环境的适应性。结果表明, 拉鲁湿地和茶巴朗湿地种群的年龄结构以1龄和2龄为主, 最大年龄均为4龄, 而南京江宁的年龄结构以3龄和4龄为主, 最大年龄为5龄; 拉鲁湿地种群体长和体重的关系式为 W_♂=0.021 L2.966(r2=0.982)、 W_♀=0.014 L3.224(r2=0.986), 茶巴朗湿地为 W_♂=0.011 L3.282(r2=0.990)、 W_♀=0.014 L3.123(r 2=0.989), 南京江宁为 W_♂=0.014 L3.146(r2=0.939)、 W_♀=0.028 L2.763(r2=0.894); 拉鲁湿地种群鳞径与体长的关系式分别为 L_♀=21.676 R+7.766(r2=0.886)、 L_♂=29.184 R0.792( r2=0.886), 茶巴朗湿地为 L_♀=16.946 R+15.048 (r2=0.857)、 L_♂=18.290 R+13.157(r2=0.858), 南京江宁为 L_♀=33.710 R0.607(r2=0.686) 、 L_♂=16.194 R+20.485(r2=0.800); 拉鲁湿地繁殖群体的绝对繁殖力(926±476)粒和卵径(0.92±0.10) mm, 茶巴朗为(364)粒和(0.97) mm, 南京江宁为(1220±704)粒和(1.00±0.13) mm。相比于原产地种群, 拉鲁湿地和茶巴朗湿地的年龄结构偏低, 平均体长均较短; 在生长特征上相同年龄段的个体相对较小、生长速度相对较慢; 在繁殖策略上绝对繁殖力较少、卵径较小。高原的低温条件与食物匮乏可能是造成了麦穗鱼生长速率低、怀卵量减少等可塑性变化的重要原因。     

拉鲁湿地夏秋季纤毛虫群落特征及其与水环境的关系

为了解西藏拉鲁湿地夏、秋季纤毛虫群落结构及水环境质量变化特征,于2011年7、10月和2012年7、10月,用活体镜检和固定染色相结合的方法,对拉鲁湿地夏、秋季纤毛虫物种多样性及群落结构特征进行了研究。鉴定纤毛虫110种(包括15个未定名种),隶属于3纲13目44科53属;下毛目和前口目为优势类群,核残迹目和合膜目为偶见类群,其余为常见类群;优势种类夏季有毛板壳虫(Coleps hirtu)、珍珠映毛虫(Cinetochilum margaritaceum)、旋回侠盗虫(Strobilidium gyrans);秋季无优势种类;拉鲁湿地夏、秋季纤毛虫群落结构复杂,物种组成与分布呈现高度的时空异质性;平均多样性指数秋季(3.3)高于夏季(2.7);纤毛虫群落特征参数与水环境主要理化因子的二元变量相关性分析显示,夏季纤毛虫物种数和群落结构与水温呈极显著负相关;综合评价显示,拉鲁湿地水环境受到轻度污染。     

青藏高原天然湿地水环境特征和水质净化能力分析

研究以拉萨市拉鲁湿地及其相连干渠和茶巴朗湿地水体为研究对象, 分别于2020年8月(夏季)和2021年4月(春季)各采集22个水样, 测定水体氮磷营养盐和高锰酸盐指数, 分析了夏季和春季湿地的水环境特征和水质净化能力。结果表明, 拉鲁湿地和茶巴朗湿地由于流域人为污染水平不同进水水质存在差异, 拉鲁湿地进水水质主要受氮磷营养盐影响, 茶巴朗湿地水质主要受耗氧有机物影响。两湿地对水质都具有净化作用, 不同季节湿地对不同污染物的去除效果也有所差异。夏季, 拉鲁湿地对TN、NH₃-N、NO₃-N、TP和SRP的最大去除率分别为75.0%、65.2%、89.5%、82.2%和35.3%。茶巴朗湿地对TN、NH₃-N、NO₃-N、TP和SRP的去除率分别为60.7%、73.5%、12.7%、35.9%和5.0%。夏季两湿地对COD_Mn均未表现出去除作用。春季, 拉鲁湿地对TN、NH₃-N、NO₃-N、TP、SRP和COD_Mn的最大去除率分别为35.2%、65.9%、56.8%、59.5%、62.3%和17.9%。茶巴朗湿地的水质净化效果较差, 对TN、NH₃-N、NO₃-N、TP、SRP和COD_Mn的去除率分别为2.2%、10.2%、11.3%、11.3%、9.0%和26.0%。湿地水生植物、湿地结构、特殊的水动力特征及水污染负荷都可能影响高原湿地的水质净化能力, 春季高原湿地较低的水温、植物丰度和水文条件可能会降低湿地对污染物的去除效果。     

海口五源河国家湿地公园鱼类群落结构及多样性研究

湿地是自然界生物多样性丰富、人类赖以生存和发展的环境之一，在生态系统中扮演着十分重要的角色。以往对湿地鱼类的研究一直相对匮乏，不利于进行湿地保护和湿地公园的开发和建设，本研究基于2021—2022年期间对海口市典型湿地——五源河湿地公园的鱼类群落调查数据，研究了该湿地公园鱼类群落结构及多样性。调查发现该湿地公园鱼类70种，隶属9目28科61属，其中纯淡水鱼类41种，河口鱼类29种；纯淡水鱼类中土著鱼类29种，外来鱼类12种；受威胁鱼类6种，海南特有种2种。湿地公园鱼类生态类型以杂食性、底层性、定居性鱼类为主；海南似鱎（Toxabramis houdemeri）、齐氏非鲫（Coptodon zillii）、须鲫（Carassioides acuminatus）、豹纹翼甲鲇（Pterygoplichthys pardalis）为该湿地公园的优势种；鱼类群落的Shannon-Weiner指数、Margalef指数、Pielou指数和Simpson指数平均值分别为2.11、5.19、0.59和0.26。结果表明，五源河湿地公园的鱼类多样性较高，但部分河段受到外来物种入侵和人为干扰的影响较大，亟需实施针对性的保护措施。     

拉萨国家级自然保护区拉鲁湿地发现牛蛙

原产于美国落基山脉以东地区的牛蛙(Rana Catesbeiana )是一种非常危险的外来物种。 2014年6月14-24日在拉萨市国家级自然保护区拉鲁湿地内发现成 、幼体 的牛蛙。建议借助政府、知名宗教人士、媒介等力量,以制度、呼吁、宣传等有效渠道,尽快解决湿地放生牛蛙的问题,以降低湿地现有牛蛙的种群增长及栖息地的进一步扩大。     

拉萨拉鲁湿地夏季鸟类调查初报

20 0 4年 8月采用样线法调查了拉萨市拉鲁湿地夏季鸟类的种类和数量 ,共记录到 2 6种鸟。鸟类群落中以灰沙燕 (Ripariariparia)、红脚鹬 (Tringatotanus)为优势种 ,优势度明显 (D =0 . 40 8) ,但群落多样性不高 (H′=1 . 5 3 1 )。拉鲁湿地夏季鸟类群落中涉禽和草甸鸟类占主导地位 ,标示着湿地表面水位下降、趋向于草原化的环境变化特点     

拉萨河流域外来鱼类的分布、群落结构及其与环境的关系

为揭示当前拉萨河流域外来鱼类的现状及其主要影响因素,于2010、2012及2014年对该流域的鱼类群落结构及水体环境进行了调查。共捕获4目6科17属25种鱼类,包括13种外来鱼类和12种土著鱼类。在42个采样点中的19个发现了外来鱼类,包括12处的湿地、6处的河流及1处水库采样点。外来鱼类基本都分布在下游,除了鲫（Carassius auratus）分布到了上游,鲤（Cyprinus carpio）、鳙（Aristichthys nobilis）和泥鳅（Misgurnus anguillicaudatus）分布到了中游。分布最广、数量最多的土著鱼类是拉萨裸裂尻鱼（Schizopygopsis younghusbandi younghusbandi）、东方高原鳅（Triplophysa orientalis）和西藏高原鳅（Triplophysa tibetana）,最常见的外来鱼类为泥鳅、鲫和麦穗鱼（Pseudorasbora parva）。典范对应分析表明,该流域的鱼类群落同时受局域和区域环境因素的作用,二者对鱼类群落变异的总解释量为33.9%。海拔、圆石的比例和沙的比例与鱼类群落结构的关系最为紧密。今后应当开展外来鱼类的监控和清除工作,减少人为活动对河流生态系统的干扰,以促进该地区外来鱼类的防控工作及土著鱼类的保护。     

西藏拉鲁湿地水体冬季可培养丝状真菌多样性及其与理化因子的关系

【背景】拉鲁湿地是我国海拔最高、面积最大的城市天然湿地。开展拉鲁湿地微生物群落结构分析,可为青藏高原生物资源的开发利用和保护提供理论依据,并为湿地生态系统的微生物多样性研究奠定基础。【目的】开展拉鲁湿地水体丝状真菌的多样性研究,探究影响该环境丝状真菌群落分布特征的主要理化因子。【方法】从拉鲁湿地11个水样中分离丝状真菌,应用nr DNA ITS序列分析,并结合经典分类学方法对获得的菌株进行鉴定,运用SPSS和CANOCO软件分析丝状真菌群落结构及其与环境因子的关系。【结果】从拉鲁湿地水体分离的丝状真菌菌株分属于6属13种。拉鲁湿地冬季水体丝状真菌优势属为Mucor、Cladosporium和Galactomyces,优势种为M.hiemalis、M.racemosus和G.geotrichum。总氮与拉鲁湿地水体丝状真菌数量呈显著负相关(P0.05),总氮和总磷对于丝状真菌的分布具有较明显的影响,这2种理化因子与M.racemosus的多度呈正相关性,而与M.hiemalis呈较强的负相关性。【结论】环境因子是影响高原湿地生态系统微生物群落结构的主要因素之一,探讨西藏典型脆弱生态环境中微生物多样性与环境因子的关系具有重要意义。     

西藏拉鲁湿地水体酵母菌多样性及其与理化因子相关性

【目的】开展拉鲁湿地水体酵母菌多样性研究,探究理化因子与酵母菌群落结构的相互关系。【方法】采用原位培养法从拉鲁湿地11个水样中分离酵母菌,应用26S r RNA D1/D2区域序列分析,并结合经典分类法对获得的菌株进行分类鉴定,运用SPSS和CANOCO软件分析酵母菌多样性及其与环境因子相关性。【结果】从拉鲁湿地水体中分离得到169株酵母菌,鉴定分属为15个属31个种。优势种为Ustilentyloma graminis和Filobasidium magnum,优势属为Naganishia、Ustilentyloma、Filobasidium和Cystofibasidium。统计分析结果表明,化学需氧量(COD)是影响拉鲁湿地水体酵母菌数量的显著因素,另外,此理化因子是影响Ustilentyloma分布的重要环境条件。【结论】西藏拉鲁湿地酵母菌资源比较丰富,且存在明显的空间异质性。     

Testing Strength of Biotic Resistance against an Introduced Fish: Inter-Specific Competition or Predation through Facultative Piscivory?

Biotic resistance is the process where aspects of the receiving environment inhibit the establishment and invasion of an introduced species. Resistance against an introduced fish can be through strong competition and/or predation from resident fishes. Here, the biotic resistance against introduced topmouth gudgeon Pseudorasbora parva (a highly invasive fish in Europe) by resident carp Cyprinus carpio was tested in experimental mesocosms. The introduction scenario was six adult P. parva (three male, three female) on a single occasion. Resistance to their establishment was provided by three and six resident C. carpio whose effects on P. parva growth and reproduction were compared to a Control (no resident fish at the time of introduction) and treatments containing three and six P. parva. After 120 days, the growth rates of the introduced P. parva were significantly depressed in C. carpio presence and in mesocosms with three C. carpio present, significantly decreased numbers of 0+P. parva were recorded. Where six C. carpio were present, no 0+P. parva were recorded, indicating resistance strength increased with carp abundance. In contrast, there were no differences in P. parva reproduction and growth rates between the Control and treatments containing conspecifics. Stable isotope analysis (δ(15)N, δ(13)C) revealed C. carpio were feeding at one trophic level above 0+P. parva, suggesting the process of resistance was predation (facultative piscivory) rather than competition. Thus, if P. parva are to establish and invade following an introduction, they must overcome this biotic resistance from cyprinid fishes such as C. carpio.     

Seasonal patterns in feeding ecology of three small fishes in the Biandantang Lake, China

Feeding ecology of three small fish species, Hypseleotris swinhonis, Ctenogobius giurinus and Pseudorasbora parva was studied seasonally in the Biandantang Lake, a small, shallow lake in central China. Gut length, adjusted for total body length, was significantly higher in spring than in other seasons for all the three species. Seasonal changes in gut length were not associated with changes in food quality. Weight of fore-gut contents, adjusted for body weight, was significantly higher in winter and spring than in summer and autumn in H. swinhonis and C. giurinus , and significantly higher in autumn than in spring and summer for P. parva. Percentage of empty fore-guts was highest in summer and lowest in spring for H. swinhonis and C. giurinus , and highest in winter and lowest in autumn for P. parva. Diet of the three small fishes showed apparent seasonal changes, and these changes reflected partly the seasonal fluctuations of food resources in environment. Diet breadth was high in winter and low in autumn for H. swinhonis , high in winter and low in spring and summer for C. giurinus , and high in autumn and low in spring for P. parva. Diet overlaps between pairs of species were biologically significant in most cases, except between H. swinhonis and P. parva in summer and autumn and between C. giurinus and P. parva in autumn.     

海河流域拒马河鱼类群落结构特征及其与环境因子的关系

为了解拒马河鱼类时空分布及影响因子,基于2019—2021在拒马河的6次季节性鱼类调查,分析了拒马河鱼类群落结构及其与环境因子的关系。结果显示:共采集37种鱼类,隶属5目11科,鲤形目最多,占总种数的64.86%。相对重要指数(Index of relative importance,IRI>)显示,IRI>≥500的优势种鱼类有10种,以鲫Carassius auratus Linnaeus、麦穗鱼Pseudorasbora parva Temminck & Schlegel、黑鳍鳈Sarcochilichthys nigripinnis Günther和宽鳍鱲Zacco platypus Temminck&Schlegel为主。单因素方差分析(ANOVA)表明,春、夏、秋季鱼类群落的个体数(N)、物种数(S)、Shannon-Wiener多样性指数(H’)和Margalef丰富度指数(D_Ma)存在显著差异,Pielou均匀度指数(J’)无显著差异。SNK多重比较检验(Student-Newman-Keuls)显示个体数、种类数以20...     

Non-native freshwater fishes in Norway: history, consequences and perspectives

At present, there are 43 self-sustaining fish species in Norwegian fresh waters, 11 (26%) of which are non-native, representing four families (Salmonidae, Cyprinidae, Centrarchidae and Ictaluridae). Human-mediated fish introductions probably began in the 15th century with common carp Cyprinus carpio, but most have occurred between the late 1800s and late 1900s. The number of known established populations varies from one (goldfish Carassius auratus ) to nearly 250 (tench Tinca tinca ). Dispersal risk is also highest with tench, which is being spread by anglers for its appeal as a trophy fish. Intentional introductions to improve amenity angling have been part of fisheries management programmes ( e.g. brook trout Salvelinus fontinalis ), so this appears to be an increasingly common introduction vector despite the prohibition under legislation of introducing any species of non-native fishes. Some introduced species, such as brook trout, have declined in abundance and number of populations as the quality of acidified waters has been restored, being replaced by native brown trout Salmo trutta . Further range expansion by some species ( e.g. common carp, goldfish and pumpkinseed Lepomis gibbosus ) is probably restricted by current climatic conditions.     

Dietary-morphological relationships of fishes in Liangzi Lake, China

Species in Liangzi Lake were clustered into four trophic groups: Hemiramphus kurumeus and Hemiculter bleekeri bleekeri fed predominantly on terrestrial insects; Carassius auratus auratus and Abbottina rivularis on non-animal food; Hypseleotris swinhonis, Ctenogobius giurinus, Pseudorasbora parva and Toxabramis swinhonis on cladocerans or copepods; Culterichthys erythropterus on decapod shrimps. Gut length, mouth width, mouth height, gill raker length and gill raker spacing, varied widely among species. With the exception of three species pairs ( H. swinhonis, C. giurinus; C. erythropterus, H. kurumeus; T. swinhonis, H. bleekeri bleekeri ), principal components analysis of morphological variables revealed over-dispersion of species. Canonical correspondence analysis of dietary and morphological data revealed five significant dietary-morphological correlations. The first three roots explained > 85% of the total variance. The first root reflected mainly the relationship of gut length to non-animal food, with an increase in gut length associated with an increase in non-animal food. The second root was influenced strongly by the relationship of the gill raker spacing to consumption of copepods, with an increase in gill raker spacing associated positively with copepods in the diet. The third root was influenced by the relationship of mouth gape to consumption of fish and decapod shrimps, with an increase in mouth gape associated with more fish and decapod shrimps in the diet. These significant dietary-morphological relationships supported the eco-morphological hypotheses that fish morphology influence food use, and morphological variation is important in determining ecological segregation of co-existing fish species.     

西藏两种裂腹鱼鱼肉质构特征比较分析

巨须裂腹鱼Schizothorax macropogon和双须叶须鱼Ptychobarbus dipogon是雅鲁藏布江特有的重要经济鱼类, 具有多种人体必需脂肪酸, 营养价值高, 但其组织结构和内部性状可直接影响口感。为明确西藏2种裂腹鱼鱼肉的质构特征差异, 保护西藏裂腹鱼资源及其合理开发利用, 采用质地多面剖析法(TPA)分析了西藏雅鲁藏布江日喀则江段和林芝江段的2种裂腹鱼(巨须裂腹鱼、双须叶须鱼)的12项鱼肉质构特征指标, 主成分分析(PCA)表明雅鲁藏布江林芝江段双须叶须鱼鱼肉质构特征较日喀则江段2种裂腹鱼及林芝江段巨须裂腹鱼存在较大差异。析因分析表明可将雅鲁藏布江2种裂腹鱼鱼肉质构特征归纳为硬度、克服鱼肉表面与接触物吸引力及收缩性等3大类4个主成分指标, 前4个主成分累计方差贡献率达81.472%, 可将这3大类4个主成分指标作为雅鲁藏布江裂腹鱼鱼肉质构特征的主要判定参数。研究为后续合理开发利用雅鲁藏布江不同江段的裂腹鱼类提供科学数据。     

Clinostomum complanatum (Trematoda: Clinostomatidae) in five new fish hosts in Japan.

Metacercariae of Clinostomum complanatum were found in six species of natural freshwater fishes collected at Koyama Pond in Tottori City of Tottori Prefecture, Japan. Five of these fish species are reported here as new records for second intermediate hosts of C. complanatum in Japan: the silver crucian carp (Carassius gibelio langsdorfi), the deepbodied crucian carp (Carassius cuvieri), the carp (Cyprinus carpio), the topmouth gudgeon (Pseudorasbora parva) and the rose bitterling (Rhodeus ocelatus).