雅砻江中游厚唇裸重唇鱼种群结构与生长特性

于2020年10月至2021年3月在四川省甘孜藏族自治州雅砻江江段（雅江县至新龙县）采集厚唇裸重唇鱼（Gymnodiptychus pachycheilus）样本189尾,用以研究雅砻江中游厚唇裸重唇鱼的种群结构与生长特性,分析其野生资源现状、影响因素及保护对策。结果显示雅砻江中游厚唇裸重唇鱼调查种群由3-9龄组成,其中优势年龄组为4-6龄,占样本总数的87.83%;种群平均体长和体重分别为264.1 mm和250.5 g,雌雄性比为1.48：1,雌性和雄性最小性成熟个体年龄均为4龄,对应体长分别为202.0 mm和220.0 mm,对应体重分别为105.0 g和133.0 g;种群的平均肥满度为1.22,体长（L）与体重（W）关系式为W=5.00×10^-6L^3.146（R²=0.948,n=189）,属于匀速生长类型;种群体长和体重的Von Bertalanffy生长方程分别为L_t=727.5[1-e^{-0.097（t-0.508）}],W_t=5224.9[1-e^{-0.097（t-0.508）}]^3.146;生长拐点年龄为12.4龄,对应的体长和体重分别为505.2 mm和1568.3 g。研究表明目前雅砻江中游厚唇裸重唇鱼表现出年龄结构趋于低龄化,体型趋于小型化的种群结构特点,且具有自然寿命较长、生长缓慢、渐近体长较大等生长特性,加之雅砻江饵料基础和水文条件较差等因素,推测雅砻江中游厚唇裸重唇鱼所具备的种群增长潜力较低,其野生资源的自然恢复面临挑战。因此,应尽快开展雅砻江流域厚唇裸重唇鱼野生资源的保护工作。     

饥饿对眼斑双锯鱼(Amphiprion ocellaris)幼鱼形态性状与体质量相关性的影响

本研究运用多变量路径分析技术,分析饥饿7d （饥饿组）和非饥饿状态下（对照组）眼斑双锯鱼（Amphiprion ocellaris）幼鱼的体质量和形态特征之间的相互依赖关系。实验对两种状态下的幼鱼进行体质量（g）和全长（L₁）、体长（L₂）、体高（L₃）、头长（L₄）、头高（L₅）、吻长（L₆）、尾柄长（L₇）、尾柄高（L₈）、背鳍前距（L₉）、胸鳍前距（L₁₀）、腹鳍前距（L₁₁）、臀鳍前距（L₁₂）、眼径（L₁₃）等13个形态性状（mm）的准确测定。采用相关系数、决定系数、通径系数和回归方程等统计方法分析两种状态下眼斑双锯鱼幼鱼的形态性状对体质量的影响。结果显示,两个实验组14个性状间均存在极显著相关关系（P<0.01）;剔除共线性影响后,通径分析筛选出了对照组对体质量影响显著的4个形态性状,直接作用由大到小排序：L₃ > L₂ > L₆ > L₅,间接作用由大到小排序：L₅ > L₆ > L₂ > L₃,单独决定系数由大到小排序：L₃ > L₂ > L₅ > L₆;饥饿组筛选出5个形态性状,直接作用由大到小是L₃ > L₂ > L₁₂ > L₆ > L₇,间接作用由大到小是L₇ > L₁₂ > L₂ > L₆ > L₃,单独决定系数由大到小为L₃ > L₂ > L₁₂ > L₇ > L₆;对照组和饥饿组体质量与形态性状的多元回归方程分别为：W=-0.819+0.106L₃+0.027L₂+0.006L₆-0.050L₅,R²=0.94;W=-0.778+0.078L₃+0.016L₁₂+0.015L₂-0.055L₇+0.018L₆,R²=0.930。结果表明,饥饿影响了形态性状与体质量的相关性,但饥饿和非饥饿状态下体高、体长和吻长都是影响体质量的关键因子,其中体高是最主要的因子,该结果可在眼斑双锯鱼的选育工作中对选育指标的确定提供理论支持。     

浙南近海凤鲚时空分布及生物学分析

凤鲚（Coilia mystus）作为浙南近海的经济鱼类之一,近年来,由于长期的过度捕捞,其数量迅速下降。为探究浙南近海凤鲚资源的变动情况及其生物参数,2020年5月至2021年1月对浙南近海21个调查站位进行4个航次的底拖网调查,以生物量、丰度作为资源分布的数量指标,采用ELEFAN Ⅱ技术和Beverton-Holt动态综合模型对凤鲚的生长和死亡参数进行估算并分析凤鲚资源变动趋势。结果表明：4个航次共采集凤鲚903尾,总出现率为52.4%,生物量和丰度最高值出现在夏季,分别为24.46 kg/km²和2.33×10³ ind./km²;体长范围为43~224 mm,优势体长组为100~180 mm,占全年总数的84.81%,体长（L）和体重（W）的关系式为W=1.25×10^-6L^3.2693 （R²=0.9448）;体重的生长拐点年龄为1.20 a。采用Pauly 经验公式估算出凤鲚的自然死亡系数为0.75,采用长度变换渔获曲线法估算凤鲚的总死亡系数为3.06,捕捞死亡系数为2.31,当前开发率为0.76。Beverton-Holt动态综合模型显示,浙南近海凤鲚已处于过度开发状态。为有效保护并恢复浙南近海凤鲚资源,建议设立凤鲚种质资源保护区,加强对凤鲚产卵场、仔稚鱼保育场的保护。     

雅鲁藏布江中游双须叶须鱼群体繁殖力与繁殖策略研究

双须叶须鱼Ptychobarbus dipogon隶属裂腹鱼亚科, 叶须鱼属, 是西藏特有经济鱼类, 研究通过对其繁殖力和繁殖策略的研究, 旨在为双须叶须鱼的科学保护和合理开发提供理论依据。于2013年2月至3月以及2014年2月中旬至6月中旬, 在雅鲁藏布江中游区段采集到1030尾双须叶须鱼, 雄鱼体长主要集中在325—400 mm, 雌鱼体长主要集中在375 mm以上, 其中Ⅳ期、Ⅴ期的雌鱼65尾, 体长为320—500 mm, 体重为411.6—1328.0 g。采用SL50%的方法, 雌鱼初次性成熟体长为360.90 mm, 初次性成熟年龄为13.0龄; 雄鱼初次性成熟体长为354.53 mm, 初次性成熟年龄为13.5龄。从不同月份不同性腺发育期所占比例, 不同月份的性体指数变化以及不同月份卵径分布图, 可以看出双须叶须鱼属于同步产卵类型, 集中在2—4月份。双须叶须鱼平均绝对繁殖力为3487粒, 平均相对体长繁殖力为7.2粒/mm, 平均相对体重繁殖力为4.3粒/g, 绝对繁殖力与体长、体重呈正相关, 与年龄无显著相关性。群体性比为1.23 鲶1。综上所述, 双须叶须鱼是繁殖力较低、性成熟较晚和繁殖期较短的鱼类, 我们针对其繁殖特性提出了一些保护性建议。     

3种酰胺类稻田除草剂对克氏原螯虾的急性毒性

[目的] 研究稻虾共作模式条件下,稻田封闭除草剂对克氏原螯虾产生的急性毒性。[方法] 采用半静态试验方法,研究3种酰胺类除草剂（乙草胺、丙草胺和丁草胺）对克氏原螯虾的急性毒性,计算3种酰胺类除草剂对克氏原螯虾的安全浓度,并分析其LC₅₀衰减规律。[结果] 随着暴露时间和除草剂浓度的增加,虾体侧躺,步行足和游泳足活动频率降低,最终死亡。乙草胺对克氏原螯虾的96 h半致死浓度（LC₅₀）和安全浓度（SC）分别为0.0707和0.0146 mL·L^-1;丙草胺对克氏原螯虾的96 h LC₅₀和SC分别为0.0119和0.0021 mL·L^-1;丁草胺对克氏原螯虾的96h LC₅₀和SC分别为0.0073和0.0014 mL·L^-1。乙草胺、丙草胺及丁草胺除草剂LC₅₀随着暴露时间延长呈下降趋势,符合双曲线衰减模型,回归方程分别为：① y₁=2.0840x^-0.7380（R²=0.9973）;② y₂=0.1106x^-0.4930（R²=0.9872）;③ y₃=0.2236x^-0.7480（R²=0.9990）。克氏原螯虾对3种除草剂的敏感性由高到低依次为：丁草胺 > 丙草胺 > 乙草胺。[结论] 乙草胺和丙草胺可在稻田综合种养生产过程中按常规剂量使用,而丁草胺按常规剂量使用可能存在较大的风险。     

PRGDWR-尿激酶原双功能嵌合分子的性质研究

为赋予单链尿激酶型纤溶酶原激活剂(single chain urokinase-type plasminogen activator, scu-PA, 尿激酶原)以抗血小板聚集的功能,在scu-PA的kringle区118位Gly与119位Leu之间插入PRGDWR序列（insert mutant B,InB）.利用甲醇酵母（Pichia pastoris）进行分泌表达,经金属离子螯合亲和层析与S强阳离子交换层析,得到纯蛋白.实验测定InB对人工合成底物S-2444的酰胺解活性为5 900 IU/mg,动力学常数为：K_m,S-2444^InB=56.8 μmol·L^-1,k_cat,S-2444^InB=0.33 s^-1;水解天然底物plasminogen的动力学常数为：K_m,plg^InB=0.397 μmol·L^-1,k_cat,plg^InB=0.0164 s^-1.InB激活plasminogen的反应在有fibrin存在条件下InB的活性为无fibrin条件下的46.3％.该突变体在体外激活plasminogen的活性与同一系统表达的野生型scu-PA基本相同.该突变体表现出较强的抗血小板聚集活性,IC₅₀＝12.7 μmol·L^-1,而野生型scu-PA无此功能.实验表明scu-PA的K区插入突变体InB是一种极具潜力的双功能溶栓分子.     

雅鲁藏布江中游双须叶须鱼群体繁殖力与繁殖策略研究（英文）

双须叶须鱼Ptychobarbus dipogon隶属裂腹鱼亚科,叶须鱼属,是西藏特有经济鱼类,研究通过对其繁殖力和繁殖策略的研究,旨在为双须叶须鱼的科学保护和合理开发提供理论依据。于2013年2月至3月以及2014年2月中旬至6月中旬,在雅鲁藏布江中游区段采集到1030尾双须叶须鱼,雄鱼体长主要集中在325—400 mm,雌鱼体长主要集中在375 mm以上,其中Ⅳ期、Ⅴ期的雌鱼65尾,体长为320—500 mm,体重为411.6—1328.0 g。采用SL50%的方法,雌鱼初次性成熟体长为360.90 mm,初次性成熟年龄为13.0龄;雄鱼初次性成熟体长为354.53 mm,初次性成熟年龄为13.5龄。从不同月份不同性腺发育期所占比例,不同月份的性体指数变化以及不同月份卵径分布图,可以看出双须叶须鱼属于同步产卵类型,集中在2—4月份。双须叶须鱼平均绝对繁殖力为3487粒,平均相对体长繁殖力为7.2粒/mm,平均相对体重繁殖力为4.3粒/g,绝对繁殖力与体长、体重呈正相关,与年龄无显著相关性。群体性比为1.23鲶1。综上所述,双须叶须鱼是繁殖力较低、性成熟较晚和繁殖期较短的鱼类,我们针对其繁殖特性提出了一些保护性建议。     

南方红壤典型水土流失区马尾松林地上林木碳储量的遥感监测——以长汀县河田镇为例

森林碳储量动态变化对揭示区域水土流失治理成效具有重要指示意义。以长汀县河田镇为例,2017年随机设置34个马尾松林样本作为建模集,分别与同期Landsat影像的原始波段、植被指数及主成分因子进行回归分析,构建马尾松（（Pinus massoniana））林地上林木碳储量的最佳反演模型,基于伪不变特征原理的线性归一化法实现该模型在2003、2010年影像上的适用性校正转换,实现研究区2003、2010、2017年马尾松林地上林木碳储量的反演及时空分异特征的研究。结果表明：研究区2017年马尾松林地上林木碳储量最佳遥感反演模型是以绿色植被指数（GNDVI）为自变量构建的指数模型：C₂₀₁₇=0.006e^{14.357GNDVI₂₀₁₇},该模型拟合的决定系数为0.57,平均相对精度为82.19%;2003年、2010年马尾松林地上林木碳储量遥感估测模型为：C₂₀₀₃=0.006e^{（16.4086GNDVI₂₀₀₃+1.1428）}、C₂₀₁₀=0.006e^{（15.1677GNDVI₂₀₁₀+1.5821）},两期校正模型的决定系数均在0.85以上;2003、2010及2017年碳储量分别为8.24 t/hm²、11.34t/hm²、16.14 t/hm²,整体呈上升趋势;地上林木碳储量随海拔、坡度的升高而增加,向阳坡地上林木碳储量高于背阴坡;碳储量增长率随海拔、坡度的升高而降低,背阴坡碳储量增长率高于向阳坡。     

贵州省青菜河水库坝下细肢新米虾（Neocaridina gracilipoda）的体长-体重关系研究

细肢新米虾（Neocaridina gracilipoda）是中国常见淡水虾类之一,在水域生态系统中起重要的作用（如在物质循环和能量流动中起链接作用）,但有关其基础生物学方面的研究目前却鲜见报道。有鉴于此,于2022年秋季在赤水河流域青菜河水库坝下（106°07′52″E,27°36′12″N）采集细肢新米虾490尾,通过对样本体长与体重的测定,掌握了此虾的体长和体重分布并报道了该物种的体长-体重关系。研究结果如下,青菜河水库坝下细肢新米虾：（1）体长介于10.60~32.13 mm（19.67 ± 2.54 mm）之间,优势体长集中在16.50~22.50 mm（n = 390,占总丰度的79.59%）;（2）体重介于0.01~0.44 g（0.11 ± 0.04 g）之间,优势体重集中在0.05~0.15 g（n = 415,占总丰度的84.69%）;（3）体长-体重的关系为W = 4 × 10^-5L^2.66 （R² = 0.78,n = 490）,b值（b = 2.66）与3存在显著性差异（P < 0.05）,即表明青菜河水库坝下细肢新米虾种群呈负异速生长。     

不同CO2浓度升高和氮肥水平对水稻叶绿素荧光特性的影响

为研究不同CO₂浓度升高和氮肥水平对水稻叶绿素荧光特性的影响,利用由开顶式气室（OTC）组成的CO₂浓度自动调控平台开展田间试验。以粳稻9108为试验材料,CO₂浓度设置CK（对照,环境大气CO₂浓度）、C₁（CO₂浓度比CK增加160 μmol/mol）和C₂（CO₂浓度比CK增加200 μmol/mol）3个水平;氮肥设置低氮（N₁：10 g/m²）、中氮（N₂：20 g/m²）和高氮（N₃：30 g/m²）3个水平。结果表明,在低氮条件下,与CK相比,C₁处理使拔节期的F_o上升4.8%（P=0.031）;C₂处理使拔节期的F_o上升6.3%（P=0.015）,F_v/F_m下降4.8%（P=0.003）,使孕穗期的F_o上升12.7%（P=0.039）,F_v/F_o下降18.2%（P=0.039）。在高氮条件下,与CK相比,C₂处理使灌浆期的F_m、F_v和F_v/F_m分别下降3.6%（P=0.039）、4.9%（P=0.013）和1.3%（P=0.039）。在中氮条件下,与CK相比,C₁和C₂处理的影响不明显。在整个生育期内,CO₂浓度升高与施氮处理交互作用对水稻叶绿素荧光特性的影响未到达显著水平。研究表明,大气CO₂浓度升高使水稻叶片光系统Ⅱ受损,抑制其电子传递能力、电子受体Q_A氧化还原情况、最大光化学效率和潜在活性,通过适量施氮可以有效地缓解其负面效应。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.