春、夏季舟山渔场及其邻近海域鱼类群落格局

根据2006年8月和2007年4月在舟山渔场及其邻近海域渔业资源和环境调查所获得的数据,采用非线性多维标度（MDS）和典范对应分析（CCA）方法研究了该海域的鱼类群落种类组成及群落特征.结果表明： 春季该海域共捕获鱼类62种,隶属11目36科56属,主要优势种为六丝钝尾虾虎鱼（Amblychaeturichthys hexanema）和小黄鱼（Larimichthys polyactis）,两种丰度占总丰度的82.9%;夏季共捕获鱼类58种,隶属于11目38科51属,主要优势种为六丝钝尾虾虎鱼、短鳄齿鱼（Champsodon snyderi）、前肛鳗（Dysomma anguillaaris）和发光鲷（Acropoma japonicum）,其丰度占总丰度的60.8%.春、夏两季20个站位均可划分为3个组.春、夏季出现率大于5.0%的鱼类分别有26种和30种,并且分别相应形成2个和3个组群.     

广东长潭水库浮游生物群落结构特征

长潭水库是广东梅州市重要的备用水源地,属于国家一类水源保护区。2010年7月,通过分析长潭水库浮游生物群落组成、生物量及多样性指数等群落结构特征和水体理化指标,揭示长潭水库富营养化水平。结果显示,长潭水库鉴定出55种浮游植物,隶属于6个门,优势种为绿藻门的栅藻（Scenedesmus sp.）、蓝藻门的微囊藻（Microcystis sp.）和伪鱼腥藻（Pseudanabaena sp.）、隐藻门的隐藻（Cryptophyta sp.）以及硅藻门的小环藻（Cyclotella sp.）和针杆藻（Synedra sp.）;藻类密度范围1.71×10⁶~2.44×10⁸ cells/L;浮游动物共检出44种,包括轮虫、枝角类和桡足类,其中轮虫是主要类群。综合营养状态指数评价结果显示,长潭水库部分水体呈轻度富营养化。典范对应分析结果显示,浮游动物、溶解氧、总氮、总磷和化学需氧量是影响长潭水库浮游植物群落结构的关键环境因子。     

三峡水库175 m试验性蓄水期库区及其上游江段鱼类群落结构时空分布格局

根据2010—2012年在三峡水库及其上游江段5个江段的商业性渔获物调查结果,对该区域鱼类群落结构的时空分布格局进行了分析。调查中共收集到鱼类87种,隶属于8目18科63属。沿坝前江段溯河而上至库尾以上流水江段,鱼类种类数逐渐增加。采用聚类分析(CA)和非度量多维标度(NMDS)方法对三峡水库175 m试验性蓄水期间各江段的鱼类种类组成进行分析,发现这5个调查江段的鱼类种类组成可以分为两个类群:类群Ⅰ包括秭归、巫山、云阳3个库区的江段,其鱼类种类组成在各年间的差异程度较大;而类群Ⅱ包括库尾的涪陵江段以及上游的江津江段,其鱼类种类组成在各年间差异程度较小。采用CA和NMDS方法对鱼类群落结构时空分布格局的分析结果表明,5个调查江段的鱼类群落结构在各年间可以分为不同类群;云阳与涪陵江段的鱼类群落结构的相似性逐年增加,而与秭归、巫山江段的相似性逐年减少;涪陵江段与江津江段的鱼类群落结构相似性也呈逐年减少趋势。总体而言,175m试验性蓄水对库中和库尾江段的鱼类群落结构的影响较大,但对库首以及库尾以上流水江段的影响均较小。     

长白山北坡木本植物分布与环境关系的典范对应分析

 在长白山北坡海拔700～2 600 m的坡面上,海拔每上升100 m设立一个样点,共计20个样点。调查每个样点中木本植物的生态重要值,并计测样点内包括气候、土壤、林冠郁闭度在内的13个环境因子。应用CANOCO3.12软件对获得的数据进行了典范对应分析(CCA),应用CANODRAW3.0作出了种类     

不同干扰下阿拉善荒漠啮齿动物优势种对气候变化的响应

气候变化已对物种分布范围和丰富度产生了极大的影响。荒漠生态系统对气候变化的反应可能更加敏感。作为荒漠生态系统的重要组成者,了解荒漠啮齿动物特别是优势鼠种将对气候变化如何响应,对于荒漠地区生物多样性的维持将具有重要意义。2002—2010年,采用标志重捕法对阿拉善荒漠4种不同生境下啮齿动物优势种群进行了研究,分别利用Spearman相关分析以及典范对应分析(Canonical Correspondence analysis,CCA)对啮齿动物优势种群动态与年平均温度和年降水量的相关性进行了分析。结果表明,不同啮齿动物优势种对温度和降雨的响应不同,尤其以子午沙鼠表现最为显著。跳鼠对温度的适宜性要高于仓鼠科的子午沙鼠和黑线仓鼠,而仓鼠科啮齿动物对降雨的适宜性高于跳鼠。较小尺度上的人为干扰更可能从改变食性和生境的途径上加剧或缓冲降雨对荒漠啮齿动物优势种的影响,而不是改变温度对啮齿动物的作用。     

黄河口及其邻近水域夏季鱼类群落空间格局及其与环境因子的关系

基于2013年夏季(6、7、8月)在黄河口及其邻近水域进行的渔业资源底拖网调查,应用多元分析方法研究了黄河口水域夏季鱼类群落空间结构,以及其与环境因子的关系.结果表明: 该海域夏季共捕获鱼类44种,隶属于11目25科40属,以暖温性和底层鱼类为主.经聚类分析,该海域夏季各月鱼类群落可大体划分为3个站位组.经单因子相似性分析(ANOSIM),黄河口不同水域鱼类群落物种组成存在显著差异.相似性百分比分析表明,矛尾虾虎鱼、斑鰶、短吻红舌鳎、蓝点马鲛和日本鳀等是各月份各站位组的典型种及造成不同站位组间群落差异的主要分歧种.典范对应分析(CCA)表明,影响夏季鱼类群落空间结构的主要环境因子为盐度、温度和深度.     

海州湾及邻近海域冬季鱼类群落结构及其与环境因子的关系

根据2011年冬季在海州湾及邻近海域进行的渔业资源底拖网和环境调查数据,应用物种多样性指数和多元分析等方法,对该海域鱼类种类组成、多样性和群落结构及其与环境因子的关系进行了研究.结果表明: 该海域冬季捕获鱼类共60种,隶属于10目34科51属,以暖温性和暖水性底层鱼类为主.站位间物种丰富度指数介于1.14～2.84,多样性指数介于1.08～2.64,均匀度指数介于0.41～0.83之间.经聚类分析和非度量多维标度(MDS)分析,该海域鱼类群落在空间上可分为站位组Ⅰ(35° N以北水域站位)、站位组Ⅱ(靠近湾顶的近岸水域站位)和站位组Ⅲ(35° N以南水域站位).鱼类群落种类组成在站位组间及两两间的比较均差异极显著(R=0.45～0.91).典范对应分析表明,底层水温、水深和表层盐度是影响海州湾及邻近海域冬季鱼类群落结构的主要环境因子.     

西湖风景名胜区不同类型森林群落的空间分布及β多样性

通过样地调查方法、TWINSPAN、β多样性指数和DCA、CCA排序分析,研究了杭州西湖风景名胜区不同森林群落的空间分布及物种多样性沿距离梯度的分布规律.结果表明:(1)TWINSPAN和DCA分析显示,43个调查样方可分为6种群落类型,不同群落类型的生境条件和群落组成均有一定的差异.(2)随着样地间距离的增大,群落间的Sorensen指数有逐渐变小的趋势,但不一定呈规律性的减少.(3)对43个样地不同种群的生境因子(包括坡向、坡度、坡位、海拔、郁闭度等)和物种优势度的CCA分析结果显示,影响光照和水分分布的主要生境因子海拔、郁闭度和坡位对西湖山区植物群落的分布以及种群的数量特征等具有重要影响.总体而言,物种扩散限制和生境条件变化是影响森林群落β多样性的主要因子.     

三峡水库蓄水期长江万州段干支流浮游动物群落特征研究

为探明三峡水库蓄水后浮游动物的群落结构变化,于2017年11月调查了三峡库区长江万州段干、支流的水质情况以及浮游动物种类和组成变化,分析了浮游动物和水体环境因子之间的关系以及长江干流浮游动物的演替情况。结果表明：流经万州城区的长江干、支流水质都已达到富营养化状态,且支流的污染程度比干流更严重。浮游动物共检出28属39种,以原生动物和轮虫为主。长江干流的浮游动物优势种类有5种,支流有9种。典范对应分析发现,硝态氮和总悬浮物是影响冬季浮游动物种群变化最重要的环境因子。分析三峡库区万州及其周边地区长江干流浮游动物的长期演替发现,随着水环境的稳定,水体中原生动物的种类逐渐从喜流水型向喜静水型转变。与2012年同期相比,本次调查中原生动物和轮虫的相对丰度增加,浮游动物生物多样性减少,这可能和水位波动的长期影响和城市水体污染有关。     

黑河上游蝗虫与植被关系的CCA分析

蝗虫与植物间存在复杂的耦合关系,能够反映蝗虫对生境的选择和适应能力以及种群内部的协同关系。2009年6-8月在野外实地采样的基础上,采用DCA除趋势对应分析（Detrended correspondence analysis）和CCA典范对应分析（Canonical correspondence analysis）方法,研究了草地蝗虫种类组成、蝗虫群落分类、优势植物与蝗虫的对应关系。结果表明：研究区的13种蝗虫分为6个类群,不同群组间蝗虫的种类数、食性和栖境选择存在较大差异,同组内的蝗虫在发生时间、生活型和营养生态位上不重叠;蝗虫的多度与优势植物盖度之间表现出极显著相关、显著相关和不相关的复杂关系,植物对蝗虫的影响更多的表现在为蝗虫提供适宜的栖息地而不完全是食物资源,禾本科和菊科植物对蝗虫空间分布的影响最大。蝗虫分布格局受自身的生物学特性和植物群落组成差异的影响,蝗虫与植物群落和优势植物之间的关系,能够为蝗虫灾害发生与防治提供可借鉴依据。     

Evaluation of models to induce low progesterone during the early luteal phase in cattle

Two experiments were designed to evaluate models for generation of low circulating progesterone concentrations during early pregnancy in cattle. In Experiment 1, 17 crossbred heifers (Bos taurus) were assigned to either prostaglandin F_2α (PGF_2α) administration on Days 3, 3.5, and 4 (PG3; n = 9) or to control (n = 8). Blood samples were collected from heifers from Days 1 to 9 for progesterone assay. Progesterone concentrations were decreased (P < 0.03) between 18 and 48 h after first PGF_2α treatment in heifers assigned to PG3 compared with that of controls. In Experiment 2, 39 crossbred heifers detected in estrus were inseminated (Day 0) and assigned to either (1) PGF_2α administration on Days 3, 3.5, and 4 (PG3; n = 10), (2) PGF_2α administration on Days 3, 3.5, 4, and 4.5 (PG4; n = 10), (3) Progesterone Releasing Intravaginal Device (PRID) insertion on Day 4.5 with PGF_2α administration on Days 5 and 6 (PRID + PGF_2α; n = 10), or (4) control (n = 9). Blood samples were collected daily until Day 15, and conceptus survival rate was determined at slaughter on Day 16. Progesterone concentrations during the sampling period in the PG3 and PG4 groups did not differ but were less than that of controls (P < 0.01). After an initial peak, progesterone concentrations in the PRID + PGF_2α group were similar to that of controls. More heifers in the PG4 group (6 of 10) had complete luteal regression than did those in the PG3 group (3 of 10). Conceptus survival rate on Day 16 did not differ between groups. There was a significant correlation between progesterone concentration on Days 5 and 6 and conceptus size on Day 16. In summary, treatment with PGF_2α on Days 3, 3.5, and 4 postestrus appeared to provide the best model to induce reduced circulating progesterone concentrations during the early luteal phase in cattle.     

粘皮鲻虎鱼胚胎及仔鱼的发育

粘皮鲻鰕虎鱼(Mugilogobius myxodermus)的卵产出时为球型,直径0.40~0.60mm,具黏性,卵颜色淡黄,半透明,油球多且数量不固定。受精5~10min后吸水膨胀成椭圆形。水温16~18℃的条件下,胚胎发育共需138h。初孵仔鱼体长2.30~3.10mm,体高0.35~0.40mm,总肌节29~30。出膜30min~24h内鳔充气,从孵出到各鳍分化完全约需要40d。     

The hatching of common carp (Cyprinus carpio L.) embryos in response to exposure to different concentrations of cryoprotectant at low temperatures

The hatching performance of embryos of the common carp (Cyprinus carpio L.) was examined after 1, 7, 14, 21, or 28 days of storage at -8, -6, -4, -2, 0, 2, or 4 degrees C with different concentrations of methanol (0.5-7.0 M in 0.5 M steps) or varying concentrations of methanol in 0.1 M sucrose or trehalose. Preserved embryos failed to hatch after storage at -8 and -6 degrees C, regardless of the duration of storage or the concentrations tested. Likewise, there was no hatching out above 5.0 M concentration of methanol, even with the addition of sucrose or trehalose. After storage at 2 or 4 degrees C, the hatching rate was higher with mixtures of methanol (1.5 M) and trehalose (0.1 M) than with methanol plus sucrose or methanol alone. At 4 degrees C, the solution containing 1.5 M methanol supplemented with trehalose gave the highest hatching response of embryos stored for 14 days. Comparison of hatching after 24h of storage at the effective temperatures (-4, -2, 0, 2, and 4 degrees C) revealed that low concentrations of methanol were effective at high temperatures and high concentrations at sub-zero temperatures. The combination of 0.1 M trehalose with 1.5 M methanol gave the highest percentage hatching out both at 4 and 2 degrees C. At 0 degrees C, the highest percentage hatching occurred with 0.1 M trehalose plus 2.5 M methanol and at -2 and 4 degrees C, the best results were with 0.1 M trehalose plus 3.0 M methanol.     

低温对蝴蝶兰胚珠发育的影响

低温(12-18℃)处理的蝴蝶兰,授粉50 d开始分化胚珠原基、60 d胚囊处于大孢子母细胞时期,比常温(20-25℃)下的推迟10-15 d;授粉70 d,常温下的蝴蝶兰植株已完成雌配子体发育和双受精,而低温处理的蝴蝶兰仍未完成大孢子的发生过程.低温处理的蝴蝶兰,胚囊发育过程中珠心细胞提前退化,在大孢子母细胞外围形成较厚的胚囊壁.胚囊只发育到单核胚囊阶段,没有形成成熟胚囊.     

Predominant maternal egg care and promiscuous mating system in the Japanese filefish,Rudarius ercodes (Monacanthidae)

Synopsis Reproductive behavior of the Japanese filefish, Rudarius ercodes, was studied at the rocky reef off Koinoura, northern Kyushu, Japan, between June and October 1989. Aggressive display was observed between males, but they were not territorial. Males had four types of courtship behavior: vibrating, tail bending, leaning and nuzzle. Spawning occurred early in the morning. A female and 1–3 male(s) mated together on brown algae. Each female spawned repeatedly with an interval of 6–12 days. Females cared for eggs and embryos from just after spawning until hatching, 2–4 days. Female egg care consisted of tending and guarding. Females tended eggs by blowing water on them and by fanning them with their pectoral fins. Females guarded eggs by driving away fish passing nearby. In some cases, males also guarded eggs by staying near the eggs and driving away conspecific males. Whether a male cares for eggs with a female seems to be affected by the form of mating (pair mating or single female-multiple male mating), and the probability of further reproduction after spawning. Dominant males showed a tendency to pair with a specific female intermittently over a two-month period. Mating, however, did not always occur between members of such pairs, and mates appeared to be inter-changeable with a promiscuous mating system.     

不同生态因子对黄鳝受精卵孵化率的影响

This paper studied the effects of some ecological factors (temperature, pH, hatching method and ammonia) on the embryonic development of ricefield eel. The results indicated that the optimum hatching temperature of ricefield eel was 25～28℃, and no significant difference was found about the effects of pH within the range of pH 5.5～9.5 on the hatching rate of oosperm. Dripping water incubation had a higher hatching rate of oosperm than staticing water incubation, and the hatching rate of oosperm decreased with increasing ammonia content. The present study provided an available suggestion for the all-artificial and half-artificial breeding of ricefield eel.     

To hatch and hatch not: similar selective trade-offs but different responses to egg predators in two closely related, syntopic treefrogs

Risk-sensitive hatching is adaptive for species facing a trade-off between egg-stage and post-hatching risks, and environmental variation in one or both stages. Such plasticity has been found in amphibians, fishes, reptiles and spiders, with red-eyed treefrogs (Agalychnis callidryas) being the best-studied case. We assessed hatching plasticity and egg- and larval-stage risks in a closely related, syntopic species, the gliding leaf-frog (Agalychnis spurrelli). We found a lower hatching response to egg-eating snakes in A. spurrelli (9–28% of embryos escaped) than in A. callidryas (59–80% escaped). Levels of snake predation were similarly high for clutches of both species monitored at a pond in Costa Rica, and in fish predation experiments early-hatched A. spurrelli tadpoles were more vulnerable than later hatchlings, as has been shown for A. callidryas. A. spurrelli thus face a risk trade-off similar to A. callidryas, and likely would benefit from predator-induced hatching; their lower responsiveness to snakes appears nonadaptive. A. spurrelli embryos showed a stronger hatching response (57% hatched in 1 h) to submergence underwater than to snake attacks even though submergence is a less frequent risk. This suggests they have a greater capacity for early hatching than is expressed in the context of snake attacks, but have much lower sensitivity to snake cues than to flooding cues. Development in A. spurrelli is accelerated compared to syntopic A. callidryas, and spontaneous hatching is earlier and more synchronous. This is congruent with predictions based on selection by egg predators in the absence of a strong escape hatching response.     

温度对中国对虾（Penaeus orientalis）越冬亲虾性腺发育与存活率的影响

本文根据１１ａ来中国对虾越冬亲虾生产性培育试验资料的统计分析结果得出：亲虾性腺发育的起点温度为７．９±０．３℃,性腺发育成熟的有效积温为２５０．４±３３．６日度,预测性腺发育成熟所需日期公式为。升高或降低越冬期间的基础水温可控制亲虾产卵时间迟早。产卵期间间歇升降温或连续升温,可控制亲虾集中产卵的次数和亲虾产卵持续时间。亲虾越冬期间,有利于提高亲虾存活率的水温,宜控制在８．０－１３．０℃,不宜超过１３．５℃,升降温幅度不宜超过１．５℃,以１．０℃左右为好。亲虾产卵期间,有利于亲虾存活率、产后卵子孵化率和亲虾再次产卵率的适宜水温为１２．０－１５．０℃,不宜超过１６．０℃,升降温幅度不宜超过１．０℃,以１．０℃以下为好。     

不同培养条件下萼花臂尾轮虫休眠卵的萌发

为确定萼花臂尾轮虫休眠卵的最适形成条件 ,或为提高特定培养条件下形成的休眠卵的萌发率 ,对不同温度、食物、光照和 pH条件下萼花臂尾轮虫形成的休眠卵进行了萌发研究。发现不同培养条件下形成的休眠卵在不同萌发条件下的萌发历时均为实验开始后的第 1～ 7天 ,萌发率高峰均出现在第 1～ 3天。在萌发温度为15℃～ 30℃范围内 ,2 0℃下形成的休眠卵在 2 0℃的萌发温度下累积萌发率最高 ,为 5 2 5 0± 6 89% ;母体以小球藻为食物时 ,其所产休眠卵的平均累积萌发率为 2 7 92 % ,显著大于以斜生栅藻或蛋白核小球藻和斜生栅藻所组成的混合藻为食物时 ;休眠卵形成和萌发时的光照条件对其累积萌发率无显著的影响 ;pH6 5和 7 5条件下形成的休眠卵的累积萌发率较高 ,分别为 32 5 0± 7 0 7%和 38 75± 15 5 3%。本研究和已报道的研究结果表明 :不同培养条件下形成的休眠卵在不同条件下萌发时均呈同步萌发型式 ;2 0℃和pH7 5分别是武汉东湖萼花臂尾轮虫休眠卵形成的最适温度和最适 pH条件。