采样设计对近岸水域鱼类浮游生物物种丰富度估计的影响

优化调查采样设计, 利用有限的调查成本获取准确可靠的调查数据, 对于开展渔业科学调查十分重要。本研究根据 2014 年 8 月(夏季)和 10 月(秋季)、2015 年 2 月(冬季)和 5 月(春季)在黄海中南部海域调查获得的鱼类浮游生物数据, 以鱼类浮游生物物种丰富度估计为采样优化目标, 利用计算机模拟再抽样方法, 比较了不同采样设计估计鱼类浮游生物物种丰富度的效果。结果表明, 随着采样频次以及采样站位数的增加, 鱼类浮游生物物种丰富度探测率逐渐升高, 相对估计误差(REE)和相对偏差(RB)逐渐减小。分层随机采样优于简单随机采样, 分层随机采样 4 次调查设计效应值(D_e)为 0.766。不同采样频次下最优季节组合分别为春、春夏、春夏秋以及全年, 其对应的 REE 和 RB 值在同频次不同季节组合中最小, 物种丰富度探测率最高; 保持 90%的物种丰富度探测率, 分层随机采样每年调查 3 次和 4 次对应的最佳站位数分别是 80 个和 60 个。在保证精确度的前提下优化采样方法和选择不同调查频次下最佳季节组合, 可为鱼类浮游生物调查采样设计进一步优化提供参考。     

海州湾鱼类β多样性变化

海州湾海域渔业资源丰富, 但近年来由于过度捕捞、环境污染的影响, 渔业资源严重衰退。为了解海州湾鱼类 β 多样性的时空变化规律, 本研究根据 2011 年、2013—2019 年在海州湾海域进行的 8 个航次秋季渔业资源底拖网调查数据, 采用 Chao 和自助法两种非参数统计方法, 估算调查海域的鱼类物种丰富度, 并采用 Sorenson 和 Cody 指数等多种 β 多样性的度量方法, 计算了鱼类物种 β 多样性。海州湾海域调查共捕获鱼类 94 种, 鱼类物种数和 β 多样性均在近年间呈现波动下降趋势。利用 K 均值聚类将调查站位按 20 m 等深线划分为组 I (<20 m)和组 II (>20 m), 进一步的 β 多样性空间差异分析表明, 组 II 的 β 多样性呈现相对明显的下降趋势, 而组 I 无明显变化; 两组间 Cody 替代性指数随时间降低, 而 Sorenson 相似性指数略有升高, 表征了深水区与浅水区 β 多样性的变化趋势有着显著差别。研究结果表明海州湾海域的鱼类群落呈现生物同质化趋势, 该趋势的出现可能与过度捕捞、环境变化等原因有关。本研究旨在为渔业资源的养护、海洋保护区的建设提供科学依据。     

高邮湖鱼类群落结构特征

为了解高邮湖鱼类群落结构特征,采用三层刺网和单目地笼网鱼类采样工具,于2019-2020年在该湖泊设置的5个点位进行4次调查,鉴定了渔获物种类,分析了鱼类生态类型和群落结构特征指数。结果显示:高邮湖鱼类24种,隶属20属7科6目。淡水性、肉食性和中上层鱼类为优势生态型。鲫(Carassius auratus)、大银鱼(Protosalanx hyalocranius)、鳙(Hypophthalmichthys nobilis)、黄颡鱼(Pelteobagrus fulvidraco)、刀鲚(Coilia nasus)和鲢(H.molitrix)为高邮湖优势种。平均Shannon-Wiener多样性指数为1.45,Pielou均匀度指数为0.61,Simpson优势度指数为0.6,Margalef种类丰富度指数为1.91。与历史资料相比,鱼类群落多样性和丰富度指数有所提高,但群落结构受干扰程度较高。Cluster聚类和nMDS平面图显示,高邮湖不同空间的鱼类多样性差异较小;而与其北部入湖口河流水域相比,鱼类群落结构差异显著。过水性高邮湖的鱼类多样性高于河道,但总体上鱼类物种多样性处于较低水平。     

厦门湾春、秋季鱼类群落结构及其多样性

根据 2016 年春、秋季在厦门湾海域进行的渔业资源底拖网调查, 使用种类组成更替率、相对重要性指数、 相对资源量指数、物种多样性指数和多元统计分析等指标及方法对该海域鱼类种类组成、群落结构和多样性进行研究。结果表明, 厦门湾海域春、秋季共捕获鱼类 100 种, 隶属于 2 纲 13 目 46 科 74 属; 湾内鱼类春、秋季种类组成更替率为 59.60%, 优势种组成的变化主要由鱼类洄游导致, 短吻鲾(Leiognathus brevirostris)、皮氏叫姑鱼 (Johnius belengerii)和孔虾虎鱼(Trypauchen vagina)为春、秋季共有优势种; 春季平均网获质量和平均网获数量分别为 1744.24 g/h 和 160.51 ind/h, 秋季分别为 3086.18 g/h 和 153.30 ind/h, 鱼类相对资源量存在明显的季节变化; Margalef 种类丰富度指数(D)变化范围为 0.46~4.07, Shannon-Wiener 多样性指数(H′)变化范围为 0.61~2.73, Pielou 均匀度指数(J′)变化范围为 0.44~0.89; Pielou 均匀度指数(J′)春季高于秋季, Margalef 种类丰富度指数(D)和 ShannonWiener 多样性指数(H′)秋季高于春季; 等级聚类(CLUSTER)和非度量多维尺度分析(NMDS)表明, 春、秋季厦门湾鱼类群落均可大致划分为东北部和南部两个站位组群。厦门湾春、秋季鱼类群落空间结构具有明显季节差异。     

嵊泗列岛邻近海域鱼类种类组成及多样性分析

根据2017年4月于嵊泗列岛邻近海域开展渔业资源底拖网调查的渔获数据,运用相对重要性指数、Shannon-Weaver指数、均匀度指数、丰富度指数、等级聚类和非度量多维度分析、生物量曲线等方法分析该海域鱼类种类组成、优势种、物种数量空间分布、生物多样性。该海域共鉴定出鱼类33种,其中优势种有棘头梅童鱼(Collichthys lucidus)、银鲳(Pampus argenteus)、龙头鱼(Harpodon nehereus)、凤鲚(Coilia mystus)等4种;与历史数据相比,该海域春季鱼类种类数锐减,优势种更替显著。根据适温性可分为暖温性和暖水性2类,分别为17和16种。各站位鱼类物种数在9～20种之间,整体呈嵊泗列岛北部海域高于南部海域的趋势。生物多样性分析表明,均匀度指数(J′)值较低,可能是舟山水域的污染导致多样性指数偏低。聚类分析结果表明,该海域鱼类群落结构空间差异较大。ABC曲线结果表明,舟山嵊泗列岛邻近海域鱼类群落结构处于严重干扰状态。综上所述,嵊泗列岛邻近海域鱼类资源受人类活动影响强烈,鱼类多样性指数偏低,群落结构空间差异较大。     

西沙群岛珊瑚礁海域鱼类分类学多样性

为评价南中国海西沙群岛珊瑚礁海域鱼类分类学多样性和更好地保护其鱼类,根据西沙群岛珊瑚礁海域鱼类物种组成的历史资料对西沙群岛及其16座岛礁的珊瑚礁水域鱼类物种数目、平均分类差异指数和16座岛礁的G-F多样性指数作了分析。结果显示,西沙共记录鱼类661种,隶属于25目、93科、305属。其中,永兴岛(351种),华光礁(173种),东岛(160种)记录鱼类物种数目较多。西沙鱼类平均分类差异指数(Δ⁺)约为60.2,各岛礁的Δ⁺与物种数目无关。中建岛、晋卿岛、玉琢礁等岛礁鱼类平均Δ⁺显著低于西沙鱼类Δ⁺。西沙鱼类Δ⁺小于陆架和河口区鱼类Δ⁺,说明珊瑚礁海域鱼类亲缘关系比陆架和河口区域的都要接近,此外大尺度上,一般纬度越低,中国海洋鱼类Δ⁺越小。但G-F多样性测度各指数由物种数目的大小决定,一般物种数目较大的岛礁G-F多样性各指数也相对较高,而R_G-F指数更适合该海域鱼类多样性的测度。以石岛为例初步探讨了G-F指数为负的原因,一是物种数目较少,二是多样性测度的关键函数Y=-XLnX并不是单调函数所致;物种数目较大的岛礁如永兴岛、华光礁、东岛等应该成为西沙珊瑚礁海域鱼类保护的重点区域。     

南海珊瑚礁海域鱼类分类多样性大尺度分布格局

珊瑚礁区生物多样性是当今生态学研究热点之一,为更全面地了解南海诸岛珊瑚礁海域鱼类物种多样性分布格局,系统整理了20世纪70年代以来南海东沙、西沙和中沙及南沙群岛珊瑚礁海域鱼类资源调查的历史资料,研究了南海珊瑚礁鱼类分类学多样性.种类统计结果表明,目前东沙记录鱼类种类514种,西沙和中沙632种,南沙548种;各礁区记录鱼类物种数目少于预测数目,也少于全球其他生境相似的海域记录的鱼类种数.估算了南海珊瑚礁鱼类平均分类差异指数△+和分类差异变异指数∧+,结果显示,东沙△+和∧+分别为55.1、121;西沙、中沙△+为60.2,∧+为164;南沙△+为56.6、∧+为150;各礁区海域鱼类△+值均小于东海陆架海域,而∧+值均高于东海陆架海域.在种和科的分类水平上,计算了南海珊瑚礁海域与卡拉棉群岛、米尔恩湾、南沙群岛西南陆架和南海北部陆架海域鱼类的相似性系数,结果表明,西、中沙群岛与其他礁区海域鱼类在种级分类阶元上的相似性系数相差较大,所有珊瑚礁海域鱼类在科级分类阶元上的相似性系数较为接近;另外,所有珊瑚礁海域鱼类种(科)间相似性均高于其与陆架海域鱼类种(科)间相似性.对南海珊瑚礁、卡拉棉群岛和米尔恩湾等海域典型礁栖性鱼类的科的物种相对丰富度进行了Kruskal-Wallis检验,结果表明,其差异均不显著(P＞0.05).结论认为,物种多样性较高而分类多样性较低是南海珊瑚礁鱼类多样性大尺度分布格局的主要特征.     

渭河干流中下游鱼类组成及多样性分析

为了解渭河治理后中下游鱼类资源状况,于2016年5月调查了渭河陕西段鱼类组成现状及群落结构特征,并对鱼类多样性进行了分析。全河段共采集鱼类样本23种,隶属于3目8科,其中以鲤科鱼类占主导,共有13种,占总种类数56.51%。151尾渔获物统计分析显示,该河段小型鱼类较多,小型化现象明显,优势种为白鲦、鲫以及麦穗鱼。鱼类组成和多样性分析表明,不同断面鱼类群落结构存在空间差异,入黄口的潼关断面物种丰富,多样性水平较高,群落结构稳定。与历史资料相比,渭河干流中下游鱼类物种数减少,群落结构发生较大变化,其中河道改造、偷捕和滥放生等是影响鱼类群落变化的主要因素。     

辽东湾北部海域鱼类群落结构及多样性

根据2006年夏季(8月)、冬季(11月)和2007年春季(4月)、秋季(10月)在辽东湾北部海域进行的底拖网调查数据,应用相对重要性指数(IRI)、生物多样性指数和多元分析方法等研究了辽东湾北部海域鱼类群落结构特征及季节变化。结果表明:本次调查共出现鱼类39种,隶属于8目23科35属,种类组成以暖温性和暖水性鱼类为主。优势种有较明显的季节更替,季节性优势种包括矛尾虾虎鱼、斑尾复虾虎鱼、小黄鱼、梭鱼、印度鲬、大银鱼和黄,无四季共有优势种,季节性优势种组成较1998年发生较大变化。鱼类群落多样性指数季节变化范围分别为Margaler物种丰富度指数D(0.40～1.69)、Shannon-Wiener多样性指数H'(0.39～1.45)、Pielou物种均匀度指数J'(0.43～0.75),方差分析表明,3种多样性指数的季节变化差异显著。单因子相似性分析(AONSIM)表明鱼类群落结构存在明显的季节更替现象。相似性百分比分析(SIMPER)表明,小黄鱼、矛尾虾虎鱼、斑尾复虾虎鱼、斑、黄、梭鱼、印度鲬、蓝点马鲛、横带高鳍虾虎鱼、焦氏舌鳎是造成鱼类群落结构季节变化的主要分歧种。鱼类群落结构与环境因子的相关分析和BVSTEP分析表明,水温是影响辽东湾北部海域鱼类群落结构季节变化的主要环境因素。本研究可为渔业生物多样性保护和渔业资源可持续利用提供科学依据。     

胶州湾中部海域秋、冬季鱼类群落结构及其多样性研究

根据2008年9月2009年2月在胶州湾中部海域进行的逐月定点底拖网调查数据,分析了该海域秋、冬季鱼类群落结构特征和多样性变化。结果表明,该海域秋、冬季共捕获鱼类50种,隶属8目,28科,42属;秋、冬季鱼类的相对资源量存在明显的月间变化,平均网获质量为每网865.29～5173.71g,平均网获尾数为每网111～717ind。秋、冬季优势种组成有明显的季节更替现象,主要由暖温性和暖水性的季节洄游种变为地域性的暖温性和冷温性种,仅六丝钝尾虎鱼(Amblychaeturichthys hexanema)为秋、冬季的共有优势种。种类丰富度指数(R)变化范围为2.08～3.25,多样性指数(H′)变化范围为1.50～2.44,均匀度指数J′为0.52～0.76;秋、冬两季间鱼类群落物种多样性指数差异均不显著(P0.05)。聚类分析和多维标度法(MDS)分析表明,6个月的样本可分为秋季组(9～11月)和冬季组(12～2月)2个组分;单因子相似性分析(ANOSIM)表明,秋、冬季组分间鱼类群落结构无显著性差异(P0.05)。     

舟山渔场衢山岛海域春夏季鱼类数量变化

利用2008年3月和6月衢山岛海域渔业资源调查资料,研究衢山岛海域鱼类种类组成和多样性的变化,分析主要优势种密度对鱼类总密度的贡献率。结果表明,两个航次拖网调查,共鉴定鱼类30种,其中暖温种15种,暖水种13种。3月的鮸和刀鲚,6月的六丝矛尾虾虎鱼分别是本海域较重要的优势种。3月和6月鱼类重量密度分别为125.05 kg/km2和95.01 kg/km2,尾数密度为8.41×103ind/km2和37.74×103ind/km2。鱼类重量密度与尾数密度分布趋势一致,呈现调查水域南部高于北部的分布趋势。依据贡献β值,衢山岛海域鱼类数量的变化与主要优势种数量变化有关。鱼类的种类组成与水团有着密切关系。     

黄河口及其邻近水域浮游动物群落结构特征及其季节变化

根据2013年8月、10月和2014年2月、5月在黄河口及其邻近水域4个航次的调查数据,分析了该海域浮游动物的种类组成、数量变动、优势种、种类多样性及其季节变化。本次黄河口及其邻近水域调查共鉴定浮游动物43种,其中原生动物、毛颚动物、尾索动物和栉水母各1种,刺胞动物8种,浮游甲壳类18种,浮游幼体及鱼卵、仔稚鱼共13种(类)。浮游动物的平均丰度为2115.64 ind/m~3,不计夜光虫的平均丰度为95.93 ind/m~3,其中浮游甲壳类占71.43%。浮游动物丰度存在显著的季节变化,数量高峰出现在春季(5月),其次为冬季(2月)、秋季(10月)和夏季(8月)。毛颚动物强壮箭虫(Sagitta crassa)和双刺纺锤水蚤(Acartia bipinnata)、小拟哲水蚤(Paracalanus parvus)等桡足类为夏、秋、冬三个季节的主要优势种,夜光虫(Noctiluca scintillans)为春季的绝对优势种。浮游动物群落物种丰富度指数(D)、Shannon-Wiener指数(H')和均匀度指数(J')的变化趋势一致,表现为夏秋季高,冬春季低。黄河口及其邻近水域浮游动物的群落结构特征具有明显的季节变化;桡足类和浮游幼体是主要类群,对该水域浮游动物的数量变动及种类多样性的变化具有较大影响。     

On species and speciation with reference to the fishes

The nature of species and the processes in which they participate are subjects of continuing debate among evolutionary biologists. I begin by examining how ichthyologists treat species empirically. Such treatments provide a pattern of species and their relationships over time and space. I suggest that this empirical record points to a predominant mode of speciation: vicariant, Model I, allopatric speciation. I also suggest that species are real and that they are individuals. There is a single species concept, the evolutionary species concept (ESC), that best captures the way we think about fish species. This concept is also well integrated with the manner in which species are treated in Phylogenetic Systematics and with the philosophical concept that species are particulars rather than universals.     

中国渔业生物DNA条形码信息平台构建及应用

构建DNA条形码数据信息系统是规范管理DNA条形码数据和实现数据共享的有效解决方案。项目在采集我国重要渔业生物的凭证标本及相应DNA条形码的基础上,通过统一提交数据的规范格式,实现物种、凭证标本和DNA条形码的三级关联,构建了中国渔业生物DNA条形码信息平台(http://www.fishery-barcode.cn)。该平台数据信息由物种名录数据库、凭证标本数据库和DNA条形码数据库组成,涵盖6020种渔业生物的凭证信息和DNA条形码资源。平台能够提供方便的网络查询,实现未知渔业生物样本的DNA条形码物种鉴定。研究首次构建涵盖我国重要渔业生物的DNA条形码信息平台,通过平台实现国内外数据共享和合作交流,为渔业生物分类、种质资源利用、濒危物种保护和水产品物种物种鉴定提供重要数据资源。     

Rainbow trout effects on zooplankton in the reproductive area of the critically endangered hooded grebe

1. Aquaculture in arid Patagonia is potentially affecting the hooded grebe (Podiceps gallardoi), a critically endangered endemic waterbird. Exotic rainbow trout (Oncorhynchus mykiss) were stocked from 1994 in naturally fishless lakes, the primary reproductive habitat of this grebe.
2. Trout and grebes are visual predators, whose diets overlap. Consequently, trout could reduce the abundance of prey of the hooded grebe.
3. This study compared the size distribution and abundance of the pelagic zooplankton fraction preyed upon by trout in four fishless lakes and three lakes stocked with trout, including vegetated and unvegetated lakes.
4. The mean size of Daphnia spp. was 45% and 35% larger in fishless lakes than in stocked lakes, for unvegetated and vegetated lakes, respectively. Boeckella spp. were larger in fishless than in stocked vegetated lakes.
5. Fishless and stocked lakes had highly contrasting biomasses of large pelagic crustaceans. Amphipods were absent from the water column of all stocked lakes analysed, and were abundant in fishless lakes. Parabroteas sarsi was absent from the two large unvegetated lakes, stocked with trout.
6. These shifts in the abundance and size spectrum of the zooplankton may reflect competition between trout and hooded grebe, affecting the survival of the latter species.
7. The current conservation status of this rare aquatic bird demands the application of management tools to reduce the detrimental effects of aquaculture on their primary reproductive habitat.

Copyright © 2016 John Wiley & Sons, Ltd.     

Biological and technical evaluation of the potential of marine and anadromous fish species for cold-water mariculture

Concern about the overexploitation of wild aquatic resources, the slow recovery of the groundfish fisheries and the need to encourage the diversification of the mariculture industry of the province of Quebec (Canada) all provided strong incentive to explore the potential of a wide selection of marine and anadromous fish species for cold‐water mariculture. Starting from a list of over 45 indigenous fish species of potential commercial interest, a biotechnical review was initiated. Technical sheets for each species were produced and aquaculture‐based selection criteria covering three aquaculture approaches of development (complete life cycle, on‐growing and stock enhancement) were examined. Species were ranked according to their degree of suitability for the given biological parameters. The final classification analysis within the complete life cycle production strategy positioned the Atlantic wolffish as the top candidate species (91%) followed by the spotted wolffish and Arctic charr (87%). Growth rate, optimal growth temperature, duration of the weaning period, minimal lethal temperature, larval size and feed requirements were the determining criteria. The on‐growing scenario final results ranked Arctic charr first (84%) followed by Atlantic cod (79%) and Atlantic halibut (74%) mostly owing to their growth rate at low temperature and optimal growth temperature criteria. Stock enhancement programmes should concentrate their efforts on the striped bass (56%), the haddock (54%) and the Atlantic sturgeon (34%) based on their growth rate, fishery status, landing price and the availability of impact studies.     

Feasibility of a single-species quota system for management of the Malaysian multispecies purse-seine fishery

Malaysian fisheries employ multiple measures to improve management; however, not all are well-suited to the multispecies fisheries. As part of a pilot project, an individual quota system was introduced for the purse-seine fishery off the East Coast of Peninsular Malaysia (ECPM), but no assessment of this particular measure nor the feasibly of its implementation has been confirmed. Therefore, this study analysed spatial and temporal patterns of purse-seine fishing, by collecting catch composition data per landing and its fishing ground within three period fishery surveys between August 2017 and September 2018 at six different landing sites. Similarity and cluster analysis examined species composition and diversity to determine the feasibility of implementing a single-species quota system in this multispecies fishery. Some overlapped of indices results and minor difference in catch composition were found due to changes in spatial and temporal fishing activities. However, no specific spatial or temporal patterns were discernible as structuring the fishing grounds used by purse-seiners. The absence of patterns, using the available data, might be attributable to huge species aggregations and widely distributed and homogenously mixed fish stocks. Thus, it is likely impractical to manage species individually in such a multispecies fishery.     

Identification of microsatellite loci and examination of genetic structure for the endangered springsnails Juturnia kosteri and Pyrgulopsis roswellensis in the Chihuahuan Desert

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Heads you win,tails you lose: Life‐history traits predict invasion and extinction risk of the world's freshwater fishes

1. Freshwater fishes have the distinction of being both a highly imperilled taxonomic group as well as one that has produced many invasive species with widespread ecological impacts. Faced with the difficult task of identifying those species with the greatest need for management action, ecologists have turned to using predictive suites of ecological and life‐history traits to provide reasonable estimates of fish invasion and extinction risk. Whether traits associated with invasiveness are the inverse of those associated with imperillment, known as the ‘two‐sides‐of‐the‐same‐coin’ hypothesis, remains unclear.
2. A global trait analysis (including maximum total body size, longevity, size at maturation, age at maturation, fecundity and egg size) for 6293 freshwater fishes was conducted to examine the trait correlates of species proneness to invasion or extinction. A meta‐analytical procedure was deployed using univariate and multivariate trait analyses that accounted for the effects of shared phylogeny.
3. Mean trait differences (measured as Hedges' d effect size) were found between invasive and threatened species when compared with native species, thus supporting the two‐sides‐of‐the‐same‐coin hypothesis for freshwater fish. Invasive species were characterized by larger body size, greater longevity, delayed maturation and higher fecundity than threatened species. Furthermore, invasive species were found to display greater trait variability compared with threatened species, suggesting that different traits may be selected at different stages of the invasion process (from pathway entrainment to establishment) whereas more specific trait combinations may predispose species to higher extinction risk.
4. The present study demonstrated a strong trait basis to global‐scale invasion risk and extinction vulnerability for freshwater fishes. Given that both time and resources are too limited for detailed species‐by‐species assessments, the results suggest that trait correlates provide a reasonable estimate of invasion and extinction risk that can inform more targeted and proactive conservation strategies.