繁殖期4种淡水鱼类化学预警行为及其与性腺指数的关联

化学预警信息（Chemical alarm cue,CAC）在鱼类捕食者-猎物关系中发挥重要作用,并与二者生存适合度密切关联。繁殖期鱼类的繁殖生理投入和化学预警响应均具有较高的能量需求,因而可能存在某种程度上的生存-繁殖的权衡（Trade-off）。选取高体鳑鲏（Rhodeus ocellatus,卵生,繁殖投入较低）、斑马鱼（Danio rerio,卵生,繁殖投入较高）、孔雀鱼（Poecilia reticulata,卵胎生,繁殖投入较高）和皮球鱼（Poecilia latipinna,卵胎生,繁殖投入很高）等繁殖方式各异、能量投入不同的4种淡水鱼类为实验对象,测定了繁殖IV期实验鱼对不同浓度的化学预警信息（Damage-released chemical alarm cues,DCAC）的行为响应模式,并探究了4种实验鱼的化学预警响应与其性腺指数（Gonadosomatic index,GSI）的关联。结果表明：（1）DCAC对4种实验鱼的空间分布、活跃状态、逃逸行为等大部分化学预警响应参数均有不同程度的影响（P<0.05）;（2）4种实验鱼GSI与其化学预警响应参数的变化无显著相关性（P>0.05）（除高浓度DCAC处理组皮球鱼GSI与底栖时间的变化负相关外）。研究回答了长期以来有关繁殖期鱼类化学预警通讯是否缺失的问题,证实了繁殖期不同繁殖生理投入/繁殖对策的4种淡水鱼类均有显著的化学预警响应,提示鱼类GSI与其化学预警响应程度通常不相关（仅高风险环境下繁殖生理投入很高的物种中可能呈现负相关）。     

高体鳑鲏化学预警响应与“个性”行为的关联

化学通讯是水生动物最原始、最普遍和最主要的通讯方式之一。对捕食风险源的回避可以使猎物减少被捕食风险,但如果出现的化学信息并不代表真正的威胁,那么就会导致猎物减少觅食或求偶的机会,从而降低适合度。因此基于能量代价-生态收益的权衡可能导致动物行为决策与化学通讯模式的分化。"个性"行为（Personality）已被证实与动物的行为决定有关,然而,有关鱼类化学预警通讯与"个性"行为关联的研究至今鲜见报道。推测："个性"行为是鱼类的化学通讯模式多样化的重要内因。采捕了广泛分布于我国淡水水域的野生高体鳑鲏（Rhodeus ocellatus）并于半自然状态下探究了：（1）实验鱼对不同化学信息（池水对照组、柠檬新奇信息组、高浓度和低浓度化学预警信息（Chemical alarm cues,CAC）组）的行为响应,（2）实验鱼在新异环境（被转入新栖息地）、新异刺激（新异物理刺激）、新异食物资源下的"个性"行为及其与化学预警响应的关联。结果发现：（1）不同溶液化学信息对实验鱼静止时间与爆发游泳的变化以及摄食个体的比例等参数均有显著影响（P < 0.05）。其中,柠檬组（未知"假风险"）与对照组相比无显著差异（P > 0.05）,实验鱼对不同浓度CAC（已知"真风险"）表现出不同程度的行为响应,高浓度和低浓度CAC均导致摄食个体比例下降（P < 0.05）,但只有高浓度CAC导致静止时间和爆发游泳的变化增加（P < 0.05）。可见,实验鱼对外源化学信息有准确高效的行为应答。（2）实验鱼静止时间比对不同溶液化学预警响应的变化与新异刺激下的活跃性显著负相关（P < 0.05）,但与新异环境下的活跃性无关（P > 0.05）,提示"个性"行为与化学预警响应有关但这种关联可能又有一定的环境依赖性（例如测试环境的稳定性与可预测性）。     

两种生态相关猎物鱼个性的种间差异及其捕食者效应

为探究不同猎物鱼个性的种间差异及其捕食者效应, 实验以乌鳢(Channa argus)为天然的捕食者, 选取自然界通常形成混合种群的高体鳑鲏(Rhodeus ocellatus)和麦穗鱼(Pseudorasbora parva)作为猎物鱼, 设置有捕食者和无捕食者处理组开展同质园实验; 之后, 分别测定了经历捕食环境处理的两种猎物鱼的探索性、活跃性和勇敢性3类个性特征, 分析两种猎物鱼个性特征的种间差异及其环境依赖性。结果发现: (1)高体鳑鲏和麦穗鱼个性存在显著的种间差异, 不管是否经历捕食者处理, 高体鳑鲏的探索性、活跃性和勇敢性均显著强于麦穗鱼(P<0.05); (2)捕食者处理导致高体鳑鲏和麦穗鱼探索性和勇敢性有增强的趋势, 但对二者的活跃性均无显著影响(P>0.05); (3)捕食者处理弱化了高体鳑鲏和麦穗鱼不同个性特征的种间差异, 强化了各自不同个性特征的偶联。结果提示: 两种猎物鱼个性特征的种间差异显著且均具有捕食者效应, 有捕食者环境下两种猎物鱼个性特征的种间差异变小, 表现出趋同化适应的趋势。     

孔雀鱼产仔前后代谢水平与逃逸能力的比较

为了探究繁殖状态对卵胎生鱼类生存适合度的影响,本文比较了孔雀鱼(Poecilia reticulata)产仔前后的静止代谢率(resting metabolic rate,RMR)、快速启动逃逸能力的变化特征以及产仔前以上生理生态参数与产仔量的关联。结果表明:产仔前实验鱼的RMR显著高于产仔后(P0.05),并与产仔量呈显著正相关(P0.05);产仔前后实验鱼快速启动逃逸能力相关参数无显著变化(P0.05),产仔前最大线速度Vmax、单位时间内的质心移动位移D120 ms等均与产仔量不相关(P0.05)。研究表明,孔雀鱼繁殖需要较大的能量投入,而快速启动逃逸能力作为生存适合度的重要参数不受繁殖状态的影响,这可能与该物种的进化策略有关。     

温度驯化对高体鳑鲏热耐受及低氧耐受能力的影响

为了考察温度驯化对鱼类热耐受及低氧耐受能力的影响,以高体鳑鲏(Rhodeus ocellatus)为对象,分别在15、20和25℃条件下驯化14 d,随后在不同驯化温度下测定其温度和低氧耐受指标。结果表明:高体鳑鲏的临界高温(CTmax)和致死高温(LTmax)随驯化温度的升高而上升,临界低温(CTmin)和致死低温(LTmin)随驯化温度的降低而下降,说明高体鳑鲏的热耐受性具有温度依赖性;高体鳑鲏在各驯化温度下的温度耐受幅分别为29.34、30.18和28.01℃;高体鳑鲏的低温驯化反应率在15~20℃和20~25℃的驯化温度范围分别为0.23和0.87,说明高体鳑鲏的低温耐受能力在高温段具有更高的温度敏感性;而高温驯化反应率在不同温度范围差别不大(0.40和0.44);高体鳑鲏失去平衡氧压则随着驯化温度的升高而上升,表明温度上升降低了高体鳑鲏的低氧耐受能力。     

人工饲养东方白鹳繁殖期行为的时间分配

对哈尔滨动物园一对东方白鹳(Ciconiaboyciana)繁殖期行为的时间分配做了观测分析,统计在某个时间单位(如孵化期)及整个繁殖期各行为所占的比例,比较得出东方白鹳因性别、繁殖期阶段等不同因子在行为上产生的差异。结果表明,繁殖期笼养东方白鹳的行为及其时间分配主要为站立(4 9 4% )、繁殖(1 9 7% )、理羽(8 9% )、取食(6 4% )、修巢(5 7% )、打嘴(5 7% )、游走(4 3 % )等几种,各种行为时间分配存在着一定的日节律。繁殖期的不同阶段、不同性别之间行为时间分配存在着一定的差异。     

鳑鲏的生物学特性及观赏价值

鳑鲏是我国特有的原生鱼类,详尽阐述了鳑鲏鱼的外部特征、生活习性、摄食、繁殖特点、胚胎及幼体发育等生物学特性,并就其观赏价值做出探讨,具有很好的开发前景。     

麝的通讯行为

麝的通讯行为包括视觉、听觉、触觉和化学通讯,以化学通讯为主。通讯行为存在于麝的每一个生活史阶段,在繁殖期和哺乳期,各种通讯联系更加频繁。通讯行为对麝科动物种群的生存、生长和繁殖均起着十分重要的作用。     

高体鳑的生物学资料及个体发育观察

2003年2月～2004年4月对高体鳑鲏(Rhodeus ocellatus)的生物学特性及个体发育进行了初步研究.高体鳑鲏栖息于水流较缓的水体中,其生活温度为4～40.2 ℃;1龄即性成熟,繁殖期在每年的2～10月,卵巢的成熟系数为10.54%±4.05%(n=68),输卵管长(28.32±10.97)mm(n=68),精巢的成熟系数为6.19%±3.46%(n=45),输精管长(2.73±1.46)mm(n=45),产卵期水温12.6～22.3 ℃;亲鱼分批产卵,每批成熟卵子的绝对量为20～69 粒,平均47粒.高体鳑鲏个体发育分为胚胎期、仔鱼期、稚鱼期、幼鱼期及成鱼期6个时期,分别记述了各阶段外部形态的变化和内部器官的发育以及不同时期出现的集群、摄食等生物学特性.     

笼养黑颈鹤粪便性激素水平的时间动态

黑颈鹤(Grus nigricollis)为国家Ⅰ级重点保护野生动物,由于其生存的自然环境恶劣,野外种群数量少,许多动物园以及保护区等机构用迁地保护的方式对黑颈鹤进行保护和繁育,然而长期以来笼养黑颈鹤繁殖率低。本研究运用非损伤的研究方法,并结合行为观察,对繁殖期黑颈鹤的繁殖生理特征进行了探索研究。结果表明,进入繁殖期黑颈鹤的雌二醇水平显著升高,可作为有效监测雌性黑颈鹤繁殖期生理状态的重要生理指标之一;繁殖前期雄性黑颈鹤的睾酮水平显著升高,与非繁殖期以及繁殖期的其他阶段差异显著,表明睾酮可有效监测雄性黑颈鹤的繁殖生理状态,为人工采精选择合适的时间提供理论基础;交配成功的雌性黑颈鹤繁殖中期的孕酮水平极显著高于其他阶段,表明该指标可有效监测雌性黑颈鹤的交配状态。综上,通过非损伤性的采样研究手段,遴选合适的生理指标参数可以为黑颈鹤的人工繁育提供理论依据。     

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.     

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.     

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.     

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.     

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.

     

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.