中国海才女虫属复合体(多毛纲:海稚虫科)种类记述

才女虫属复合体隶属于多毛纲、海稚虫科,是多毛纲中寄生种类多样性最高的群体之一。本文描述了该复合体在中国海所分布10种的形态学特征和生物学属性。此10种分别为吻蛇稚虫、小蛇稚虫、美角才女虫、难定才女虫、腺袋才女虫、邻近才女虫、触角伪才女虫、膜质伪才女虫、短鳃伪才女虫和网格伪才女虫。其中,邻近才女虫为一新种,该新种主要形态学特征在于其尾部背、腹面皆具缺刻,且头部背面无中触手。中国海分布的大多数才女虫属复合体种类既可以在松软底质上营管栖生活,也可以寄生于某些海洋生物。本文报道的种类中只有邻近才女虫和短鳃伪才女虫未见有寄生现象。中国海才女虫属种类最常见的寄主是贝类(双壳类、腹足类)和珊瑚。     

陵水才女虫与威氏才女虫的比较和地理分布研究

采用形态学与分子生物学方法相结合,对陵水才女虫(Polydora lingshuiensis)和威氏才女虫(P.websteri)进行了比较与鉴定研究,并调查了它们的地理分布。在形态上,陵水才女虫的脑后脊上具中触角、粗足刺刚毛近末端具凹陷;而威氏才女虫无中触角、粗足刺刚毛具侧凸缘。遗传距离分析结果显示,基于核糖体18S基因、线粒体COⅠ基因、线粒体Cyt b基因的陵水才女虫和威氏才女虫的种间遗传距离明显大于其种内遗传距离。基于COⅠ、Cyt b的才女虫的种间种内遗传距离比率远大于基于18S的遗传距离比率。才女虫的COⅠ与Cyt b基因的条形码间隔比18S的更宽,分辨率更高,更适用于形态相似种的辅助鉴定。在中国海域,陵水才女虫和威氏才女虫均属于宿主特异性低、地理分布性广的才女虫种类,其传播途径可能与其宿主的养殖方式以及商业运输密切相关。     

河北白洋淀鱼类外寄生车轮虫属分类研究

2009年4月—2010年10月对河北省白洋淀营外寄生生活的车轮虫属进行种类鉴定工作。采用干银染色法显示车轮虫的附着盘结构,活体吉姆萨染色方法显示细胞核形态。采用"统一特定方法"和"齿体定位描述法"鉴定出车轮虫属9种,分别为显著车轮虫、拟黑色车轮虫、网状车轮虫、杜氏车轮虫、异齿车轮虫、喙状车轮虫、卡氏车轮虫、短棘车轮虫、适度车轮虫。波氏吻鱼叚虎鱼为显著车轮虫、拟黑色车轮虫、网状车轮虫的新宿主记录,黄黝鱼为异齿车轮虫和杜氏车轮虫的新宿主记录,麦穗鱼为喙状车轮虫的新宿主记录,鲫鱼和圆尾斗鱼为适度车轮虫的新宿主记录。该研究是白洋淀地区乃至华北地区车轮虫属首次细致的分类描述,研究结果将有助于阐明白洋淀鱼类寄生车轮虫区系组成。     

盐度对才女虫幼虫存活的影响

试验结果表明,采自盐度16水体中的才女虫（Polydora sp.)幼虫,其24h存活盐幅为40－3;采自盐度5水体中的才女虫幼虫,其24h存活盐幅为15－3。盐度16水体中的才女虫幼虫经过逐步驯化后,盐度生态幅增大,其24h安全存活盐幅为50－2。     

贝尼登虫及其危害的研究进展

贝尼登虫(Benedenia)隶属于扁形动物门吸虫纲单殖目分室科贝尼登亚科,因其分布范围广,繁殖速度快,传染程度严重,对宿主的专一性不强,以及较强的致病性,贝尼登虫病已成为海水养殖一种严重的寄生虫病。1998年福建宁德地区因贝尼登虫病暴发流行,大黄鱼的自然感染率达70％以上,死亡率达30～40％,最高可达90％以上,所造成的经济损失达到甚至超过细菌性疾病。本文对贝尼登虫及其危害的研究现状作一简单介绍,旨在为控制该病蔓延提供一定的参考。     

盐度和茶籽饼对利氏才女虫幼虫影响的研究

试验结果表明:利氏才女虫幼虫对盐度的适应能力与原栖所的盐度有关,来源于较高盐度的利氏才女虫对高盐度的适应能力较强,来源于较低盐度的对低盐度适应能力较强,盐度驯化能增强利氏才女虫幼虫对盐度的适应。在试验温度17℃、盐度19.5的条件下,茶籽饼对利氏才女虫幼虫的存活有显著的影响,茶籽饼对利氏才女虫幼虫的24 hLC50和48 hLC50值及其95%置信区间分别是:4.81(4.10~5.64)mg/L、3.85(3.42~4.34)mg/L。     

2种药物对蟹苗池中利氏才女虫幼虫的防治效果

质量浓度为1．5g／m^3的漂白粉溶液和10mg／L的茶籽饼溶液都能对利氏才女虫的防治达到较好的效果。综合生产和经济效益等几个方面因素考虑,在河蟹育苗生产实践中选择质量浓度为10mg/L的茶饼可有效杀灭育苗池中的利氏才女虫,并在实际生产中也收到了良好的效果。     

利氏才女虫幼虫对轮虫和河蟹溞状幼体的影响

试验结果表明，利氏才女虫（Polydra ligni)幼虫对褶皱臂尾轮虫（Brachionus plicatilis)的存活有严重危害，其密度与轮虫的存活率负相关；利氏才女虫幼虫对中华绒螯蟹（Eriocheir sinensis河蟹）Ⅰ期和Ⅱ期蚤状幼体（Z1和Z2）的变态也存在严重危害，其密度与Z1和Z2的变态率亦呈负相关，对利氏才女幼虫的危害机理进行了讨论。     

卤虫的研究进展

卤虫(Artemia)作为虾、蟹、海水鱼、淡水鱼及观赏动物幼体养殖应用最广的生物饵料,其营养价值较高,近年来对卤虫深入探究已经成为研究热点,为了更好地促进卤虫生长及提高其存活率,本文主要对卤虫的生活习性、营养成分及环境因素对其影响做出阐述。     

大眼鲷匹里虫病及其病原体的研究——包括匹里虫属一新种的描述

本文报道了我国南海北部湾及广东湛江、广西北海等地沿海水域大眼鲷的一种微孢子虫病,病原体是大眼鲷匹里虫(新种)Plistophora priacanthicola sp．nov．,定名为大眼鲷匹里虫病(plistophorasis)。这种病的危害,主要是影响大眼鲷的生殖腺发育,严重感染者,其腹腔内充满病原体的大量孢囊,生殖腺萎瘪变形,鱼体瘦弱,腹部膨大,腹壁肌肉明显变薄。这种病原体除在长尾大眼鲷体内寄生外,在短尾大眼鲷也偶有发现,但在其他鱼类中尚未发现,这表明了该病原体对寄主有较严格的专一性。寄主对病原体的感染没有性别上的差异,而感染率则随寄主年龄增长而增大。     

合浦珠母贝4 种壳色选育系主要性状的比较分析

为评估合浦珠母贝(Pinctada fucata)白壳、黑壳、红壳和金壳色选育系F6代的育种性能,对养殖达18个月龄4种壳色合浦珠母贝的形态、质量、闭壳肌拉力和抗才女虫寄生病等12个性状指标进行了方差分析和多重比较。结果显示,4种壳色选育系间壳高、绞合线长、壳宽、体质量、壳质量、软体部质量、闭壳肌质量、闭壳肌拉力、右壳感染率和贝壳感染率均存在显著差异(P0.05)。综合相关分析表明,白壳色选育系可作为壳高和低才女虫感染率同时选育的最优育种群体,金壳色选育系可作为壳宽、体质量和闭壳肌拉力复合选育的最优育种群体。该研究结果为开展合浦珠母贝多性状复合选择育种工作提供了科学根据。     

Ecological significances of ontogenetic shifts in the stream-dwelling catfish, Hatcheria macraei (Siluriformes, Trichomycteridae), in a Patagonian river

Abstract –  The relationship between ontogenetic changes and both feeding and habitat preferences was studied in a stream catfish population of Argentine Patagonia. Fish capture, as well as habitat data recording, was performed during a 1-year long period. Larvae–juvenile transition was determined between 22.4 and 29.4 mm standard length (SL), on the basis of the relative growth changes and morphogenesis, and juvenile–adult shift was established between 61 and 65 mm SL using a macroscopic criterion of gonadal development and gonadosomatic index. Spawning period was estimated to be in the summer season, from December to February. Larvae preferred shallow marginal pools and fed mainly on small Chironomidae larvae, while juveniles and adults inhabited riffles and preyed on Ephemeroptera nymphs and Chironomid larvae. Morphological constraints during the larval period were related to habitat and feeding preferences. A complete development of fins allowed juveniles to colonise faster water habitats while a bigger mouth gape permitted them to prey on new items and on a larger size prey range.     

Egg drift and hatching success in European river lamprey Lampetra fluviatilis: is egg deposition in gravel vital to spawning success?

1. The European river lamprey Lampetra fluviatilis (Linnaeus, 1758) is a threatened species, formerly widespread throughout western Europe, for which loss and degradation of habitat is one of the main causes of decline. As with other lamprey species, areas of gravel substrate with moderate flows are considered necessary for spawning and egg development of river lamprey.
2. This study investigated the dispersal of river lamprey eggs downstream of a spawning area and the hatching success of eggs in the laboratory under a range of potential abiotic conditions (substrate type, water flow and dissolved oxygen level) which eggs could experience in nature.
3. Lamprey eggs were found to drift for a minimum of 50 m downstream of spawning excavations, facilitating dispersal in riffle habitat and to bankside depositional zones. Under conditions mimicking natural microhabitats, but without predation, median egg hatching success was 85.0% in 'spawning habitat' conditions, but surprisingly, was 50.2% in 'larval habitat' conditions with natural silt.
4. The study suggests that egg dispersal out of spawning excavations may be common in this species and demonstrates that habitat located downstream of spawning areas, even larval habitat characterized by fine sediment and moderate to low flow rates, could play an important role in larval recruitment. This suggests that even small areas of gravel or degraded spawning habitat may enable a higher degree of spawning success than has previously been assumed to be necessary for conservation or recolonization of this species.

Copyright © 2014 John Wiley & Sons, Ltd.     

Voracious invader or benign feline? A review of the environmental biology of European catfish Silurus glanis in its native and introduced ranges*

A popular species for food and sport, the European catfish (Silurus glanis) is well‐studied in its native range, but little studied in its introduced range. Silurus glanis is the largest‐bodied freshwater fish of Europe and is historically known to take a wide range of food items including human remains. As a result of its piscivorous diet, S. glanis is assumed to be an invasive fish species presenting a risk to native species and ecosystems. To assess the potential risks of S. glanis introductions, published and ‘grey’ literature on the species’ environmental biology (but not aquaculture) was extensively reviewed. Silurus glanis appears well adapted to, and sufficiently robust for, translocation and introduction outside its native range. A nest‐guarding species, S. glanis is long‐lived, rather sedentary and produces relatively fewer eggs per body mass than many fish species. It appears to establish relatively easily, although more so in warmer (i.e. Mediterranean) than in northern countries (e.g. Belgium, UK). Telemetry data suggest that dispersal is linked to flooding/spates and human translation of the species. Potential impacts in its introduced European range include disease transmission, hybridization (in Greece with native endemic Aristotle’s catfish [Silurus aristotelis]), predation on native species and possibly the modification of food web structure in some regions. However, S. glanis has also been reported (France, Spain, Turkmenistan) to prey intensively on other non‐native species and in its native Germany to be a poor biomanipulation tool for top‐down predation of zooplanktivorous fishes. As such, S. glanis is unlikely to exert trophic pressure on native fishes except in circumstances where other human impacts are already in force. In summary, virtually all aspects of the environmental biology of introduced S. glanis require further study to determine the potential risks of its introduction to novel environments.     

Habitat selection by three littoral zone fishes: effects of predation pressure, plant density and macrophyte type

Abstract— We conducted laboratory experiments which demonstrated that three littoral zone fishes differentially selected among three macrophytes when seeking refuge from predation. In the presence of a predator (a juvenile Micropterus salmoides ), mosquitofish ( Gambusia holbrooki ), sailfin mollies ( Poecilia latipinna ). and dollar sunfish ( Lepomis marginatus ) displayed ferential use of four tank areas containing patches of either Hydrilla verticillata , Potamogeton illinoensis, Panicum hemitomon , or no plants. Patterns habitat selection, and the consistency of these patterns among replicates, differed among the three fishes and among three plant-density treatments - natural (each macrophyte presented at its mean field density), equal (all three macrophytes at the same density), and control (no plants). Selection for H. verticillata by mosquitofish was significant for both the equal and natural treatments, and thus was not caused by differences in plant density alone. Sailfin mollies displayed significant selection for H. verticillata only in the natural plant-density treatments. Dollar sunfish showed less consistent habitat selection than either mosquitofish or sailfin mollies. Significant habitat selection was not found in the absence of a predator, and there was no evidence for lection among the tank areas in control treatments. Patterns of habitat selection by the three fishes in our laboratory study corresponded to observed habitat use in Lake Okeechobee.     

黄、渤海区不同生态类型鱼卵卵膜和受精孔区亚显微形态

黄、渤海区分布的硬骨鱼类鱼卵几乎涵盖了所有鱼卵生态类型。本研究借助扫描电镜观察技术对近年来黄、渤海渔业资源监测调查期间采集的15种不同生态类型鱼卵卵膜和受精孔区亚显微形态特征进行观察,以阐明其亚显微结构并总结提炼可用于鱼卵形态分类的特征,同时将相应鱼种产卵场环境因子引入到卵膜形态特征的认识中,以揭示其生境适应性。结果显示不同生态类型或不同鱼种卵膜形态不尽相同,浮性鱼卵和口含鱼卵卵膜较薄,沉性鱼卵和具卵膜丝鱼卵卵膜较厚;浮性鱼卵卵膜表面壁孔密度、卵膜外表面呈现的蚀刻或特殊结构以及受精孔形状类型,沉性鱼卵卵膜黏膜层表面结构、受精孔形状类型,具卵膜丝鱼卵卵膜丝数量、着生位置及受精孔形状类型,口含鱼卵受精孔区形状及周边附着丝数量等均可用于鱼卵形态分类。鱼卵卵膜和受精孔区亚显微结构差异与鱼种系统分类地位、产卵场环境和地理分布区相关联。鱼卵卵膜表面结构可以作为区分鱼类科或属的性状,卵膜壁孔密度、表面呈现的蚀刻或奇异结构是鱼卵形态分类的重要依据;受精孔结构则一般具有物种特异性。卵膜结构与厚度可反映鱼卵对不同生境的适应性,而卵膜表面的许多特殊结构和装饰被认为是鱼卵应对产卵场环境的保护和适应性策略。本研究将为黄、渤海区硬骨鱼类早期生活史阶段个体发生和鱼卵形态分类研究积累基础资料。