史氏菊海鞘生活史的研究进展

史氏菊海鞘为附着、滤食性无脊椎生物，为贝类筏式养殖的主要敌害生物。目前还没有找到经济、有效的防治措施。切断其生活史的某个环节，阻止其发展可能是一条途径。本文对史氏菊海鞘生活史的研究进展情况进行概述，并对其生态习性和生活史进行了详细的阐述，史氏菊海鞘具有无性出芽生殖和有性生殖两种生殖方式。出芽生殖过程中，一般7d为1个无性生殖周期，幼体的出芽生殖阶段至少持续49d；无性出芽生殖之后，开始进行有性生殖。     

单胞藻培养中敌害生物的危害及防治

在单胞藻的培养中,常会发生敌害生物的污染,而导致培养失败。为防治污染,保证单胞藻培养的成功。现把敌害生物对单胞藻的危害及防治简介如下,以供生产者参考。1敌害生物对单胞藻的危害1.1直接吞食一些较大的敌害生物,如轮虫、游仆虫、尖鼻虫、变形虫、海生残沟虫等,直接吞食藻细胞。由于单胞藻生长繁殖较快,如果敌害生物的数量不多,吞食量不大,则影响并不显著。但当敌害生物大量繁殖后,吞食量也增大,则对藻类产生严重的影响。尤其是轮虫的吞食量达到惊人的程度,在两三天内可以把藻细胞吃光,使藻液变清。1.2通过分泌有害物质对单胞藻起抑制和毒害作用一些较小的敌害生物,如小白虫、微孢子虫等通过其分泌的抗生物质对培养藻类产生毒害作用。当敌害生物分泌的抗生物质的量还较少时,培养藻类繁殖不快,生长不良。当敌害生物大量繁殖,抗生物质大量分泌后,即造成培养藻类下沉死亡,使培养失败。敌害生物分泌的抗生物质对培养藻类的毒性大小,依不同种类而异,有些种类毒性大,虽然还未在培养液中达到大量繁殖的程度,已能使培养藻类严重受害。但一般情况下,当敌害生物在培养液中达到较大数量后,才会造成严重后果。一种生物对藻类的危害作用,可能是一个方面的,也可能两个方面同时发...     

附着生物对栉孔扇贝生长及存活的影响

对荣成市桑沟湾崖头养殖场扇贝养殖笼上附着生物的种类组成、消长规律、附着生物量的季节变化以及附着生物对扇贝生长存活的影响方面进行了调查研究。结果表明：扇贝养殖笼上附着生物的种类主要有海鞘(玻璃海鞘、柄海鞘、史氏菊海鞘、紫拟菊海鞘)、水螅(主要是鲍枝螅)、多管藻、海绵等；8月份附着生物总生物量达到最高峰，9月份开始逐渐下降；倒笼次数对栉孔扇贝的生长有较大影响：在实验养殖期中，每月倒笼1次组的体重增长最快，但死亡率最高；综合个体、体重增长以及死亡率来看。以每2个月倒换网笼1次、高温季节不倒笼为最佳。     

河蟹育苗敌害生物的防治

河蟹育苗敌害生物的防治在河蟹幼体培育过程中，虽然严格要求清池和进水严密过滤，但仍不免会出现种种危害幼体的生物因子，并严重影响幼体的成活率，因此对于幼体生物敌害的防治，不能不引起重视。生物敌害主要有菱形海发藻、聚缩虫、水蜈蚣、华鳔蚤和摇纹幼虫等。一、菱...     

扁藻与金藻类生产性培养中敌害生物的防治技术

扁藻与金藻类是虾、蟹、贝类及其它海产品动物早期幼体的优质饵料，但其在生产性培养过程中常会被腹毛虫、尖鼻虫、急游虫等敌害生物污染，这些敌害生物在藻类培养液中生长、繁殖，当其数量达到一定的密度时，即对培养藻类的生长繁殖造成影响，被污染后的藻液轻者不利于再扩大培养，重     

桑沟湾筏式养殖鼠尾藻(Sargassum thunbergii)的生长特性

2014年4–6月在桑沟湾海区进行鼠尾藻(Sargassum thunbergii)海上筏式养殖实验,分析了鼠尾藻在桑沟湾的生长特性,调查了藻体上的附着生物。结果显示,(1)鼠尾藻在桑沟湾海域生长迅速,水温为10–17℃时特定生长率最高,可达6.10%/d;根据特定生长率与水温的关系,获得了鼠尾藻的最佳生长温度为14.9℃;(2)5月10日开始有生殖托形成,水温达到20.4℃时,鼠尾藻生殖托大量成熟,并有放散;(3)养殖期间,鼠尾藻最大长度达187.05 cm,均长可达112.31 cm;干湿比由0.147(4月)上升至0.189(6月);每公顷产量可达43.95 t(湿重),相当于干重为8.25 t;(4)藻体上有大型附着生物16种,主要优势种为尖嘴扁颌针鱼鱼卵、玻璃海鞘和海绵;附着生物的生物量随着水温升高而增加。研究表明,海区的附着生物对鼠尾藻的生长影响不大,在桑沟湾大规模养殖鼠尾藻是可行的。     

桑沟湾筏式养殖鼠尾藻(Sargassum thunbergii)的生长特性

2014年4-6月在桑沟湾海区进行鼠尾藻(Sargassum thunbergii)海上筏式养殖实验,分析了鼠尾藻在桑沟湾的生长特性,调查了藻体上的附着生物.结果显示,(1)鼠尾藻在桑沟湾海域生长迅速,水温为10-17℃时特定生长率最高,可达6.10％/d;根据特定生长率与水温的关系,获得了鼠尾藻的最佳生长温度为14.9℃;(2)5月10日开始有生殖托形成,水温达到20.4℃时,鼠尾藻生殖托大量成熟,并有放散;(3)养殖期间,鼠尾藻最大长度达187.05 cm,均长可达112.31 cm;干湿比由0.147(4月)上升至0.189(6月);每公顷产量可达43.95 t(湿重),相当于干重为8.25 t;(4)藻体上有大型附着生物16种,主要优势种为尖嘴扁颌针鱼鱼卵、玻璃海鞘和海绵;附着生物的生物量随着水温升高而增加.研究表明,海区的附着生物对鼠尾藻的生长影响不大,在桑沟湾大规模养殖鼠尾藻是可行的.     

科技与学术动态

激光杀灭鲍鱼壳面的苔藓虫效果明显附着在鲍鱼壳面的苔藓虫是人工筏式吊养鲍鱼的主要敌害生物之一,其大面积被覆鲍壳可导致小规格鲍鱼大量死亡。而且,营附着生活的苔藓虫种类具有角质或石灰质虫室,抗药性较强。经各种试验,     

混凝土礁体和铁制礁体附着生物群落多元统计分析

根据2008年9月对深圳杨梅坑人工鱼礁区混凝土礁体和铁制礁体上附着生物的调查资料,采用主成分分析、聚类分析和多维尺度分析方法研究了人工鱼礁附着生物组成及群落结构的基本特征.结果表明,三角藤壶(Balanus trigonus)、乳突皮海鞘(Molgula manhattensis)、翡翠贻贝(Perna viridis)、须鳃虫(Cirriformia tentaculata)、细肋肌蛤(Musculus mirandus)、美丽唇齿螺(Engina pulchra)、真蛇尾(Ophiura sp.)、变化短齿蛤(Brachidontes variabilis)、背裂虫(Opisthosyllis brunnea)、红网孔苔虫(Iodictyum axillare)、多室草苔虫(Bugula neritina)、珠带拟蟹守螺(Cerithidea cingulata)、毛偏顶蛤(Modiolus barbatus)、纹斑棱蛤(Trapezium liratum)、乳蛰虫(Thelepus sp.)和冠瘤海鞘(Styela canopus)等种类构成了人工鱼礁附着生物的主体.混凝土礁体和铁制礁体上层和下层的附着生物群落基本上聚为一类;而中层的附着生物群落没有聚为一类.     

几种常见海鞘的呼吸代谢研究

为了研究网箱、网笼上附着生物耗氧对养殖品种的影响。本文在实验室内采用静水封闭系统，对我国北方常见附着生物－－柄海鞘（Ｓｔｙｅｌａ ｃｌａｖａ），玻璃海鞘（Ｃｉｏｎａ ｉｎｔｅｓｔｉｎａｌｉｓ）和中国瘤海鞘（Ｓｔｙｅｌａ ｓｉｎｅｎｓｉ）的耗氧率进行了研究，同时，探讨了海鞘体重、温度和氧张力对耗氧率的影响。结果表明：温度和体重对海鞘的耗氧率有明显的影响（Ｐ〈０．０５）。在１２￣２８℃范围内，柄海鞘的     

舟山深水网箱污损生物季节性变化分析

于2006年7月～2007年5月对浙江舟山秀山岛和长峙岛海区深水网箱污损生物进行附着试验，揭示2个海区网箱主要污损生物种类、生物量和附着密度的月变化特征。试验得出污损生物的种类主要有水螅虫（Hydra vulgaris）、海葵（Actina sp．）、麦杆虫（Caprella kroyeri）、钩虾（Gammarus sp．）、藤壶（Balanus sp．）、贻贝（Mytilus edulis）、牡蛎（0sfrea sp．）、孔石莼（Ulva pertusa）、浒苔（Enteromorpha sp．）等及其生物量和附着密度。通过试验结果对比分析，得出了污损生物附着的月变化特征，7—11月份污损生物特别是大型藻类繁殖生长达到最盛期；11月份过后随着气温的降低，孔石莼和太平洋侧花海葵（Anthopleura pacifica）等污损生物生物量开始逐渐减少；次年3～4月份后随着气温的升高，麦杆虫、太平洋侧花海葵、强壮藻钩虾（Ampithoe valita）等污损生物牛物量又逐渐增加。     

天鹅洲长江段底栖动物的群落结构与季节变化

探究长江天鹅洲白鱀豚国家级自然保护区长江段底栖动物的群落结构及季节变化,可为该区域水生生物的保育和管理工作提供基础资料和科学依据。2014-2015年,按季节在干流江段设置16个采样站位,进行底栖动物调查和水质理化指标测定,并同步收集当月水位信息。结果表明,4次调查共检出底栖动物53种,其中水生昆虫28种,软体动物9种,寡毛类9种,甲壳动物4种,其他类群3种,常见种为日本沼虾、钩虾、栉水虱、米虾、河蚬、淡水壳菜、多足摇蚊、环足摇蚊和齿斑摇蚊。底栖动物存在较为明显的季节演替,且种类组成较为简单,以小个体的物种和活动能力较强的甲壳类为主。低水位时,生境异质性的升高有利于底栖动物多样性的增加;而高水位时生境异质性的降低,则对底栖动物的多样性不利。水位的升高以及流量的增大,有利于活动能力较强的甲壳动物生存和扩散。底栖动物的密度、生物量以及多样性处于较低水平,与该河段地处下荆江、河道演变剧烈、生境不稳有关,密度水平与长江中游的沙市、黄石断面接近,表明目前底栖动物密度处于较低水平是一种常态现象。     

海州湾海域的赤潮生物

利用2003—2008年海州湾海域浮游植物的调查资料,对海州湾海域常见的赤潮生物进行描述、归纳及总结,为赤潮的常规监测和应急监测提供背景资料。结果表明,在海州湾海域共监测到121种赤潮生物,其中重要的赤潮生物有:中肋骨条藻、夜光藻、多纹膝沟藻、短角弯角藻、赤潮异弯藻、链状裸甲藻、海链藻属,这7种(属)赤潮生物都曾经在该海域引发过赤潮。此外,中华盒形藻、海洋原甲藻、梭角藻、三角角藻、圆筛藻属、角毛藻属等赤潮生物在海州湾海域常年分布,也具有引发赤潮的可能。     

Successional development of fouling communities on open ocean aquaculture fish cages in the western Gulf of Maine,USA

Growth of fouling organisms on suspended fish cages is an impediment to aquaculture projects in coastal waters around the world. The present study characterized ecological succession of fouling communities on the netting of fish cages at an open ocean aquaculture site 10 km east of New Hampshire, USA in the western Gulf of Maine. Ecological succession can be defined as the process by which a community moves from a simple level of organization to a more complex community. Routine cleaning of the cages causes loss of organisms and initiation of ecological succession. Experimental panels of nylon net material were deployed at different times of the year and for different durations from September 2002 to September 2003 (eleven sets of 1-month panels, four sets of 3-month panels, two sets of 6-month panels, and one set of 1-year panels), with four replicates of each deployment. Panels were randomly arranged on a grid that was attached to a fish cage at a water depth of ∼ 15 m. There were substantial and significant differences in density and biomass of the total communities of most successional sequences when comparing panels deployed during May–September to those deployed during the cooler months, October–April. However, the blue mussel, Mytilus edulis, dominated in density and biomass in almost every sequence, regardless of time of initiation or duration. Other species that occurred in high numbers and/or biomass were the amphipods Caprella sp. and Jassa marmorata, the molluscs Hiatella arctica and Anomia sp., the seastar Asterias vulgaris, and the anemone Metridium senile. Juveniles and adults of some species were also present in some early (1-month) successional sequences, indicating that migration may be an important process in community development. Some of the dominant species listed above were present in all successional stages (early, intermediate and late), differing only in relative abundances in the community. The consistent dominance of M. edulis, and other differences in successional patterns compared to what has been typically observed for epifaunal communities in the region, were hypothesized to be the result of a combination of factors: a lack of predators such as seastars and fish that typically consume mussels in natural communities, excessive predation by nudibranchs on those species (e.g., Tubularia sp.) normally abundant in early successional stages, year-round availability of mussel larvae, and cage cleaning protocols that do not remove all the organisms present. The introduction of predatory fishes or seastars into or onto the cages might provide some amount of control on the growth of fouling organisms.     

Notes on kidney-infecting species of the genus Sphaerospora Thélohan (Myxosporea), including a new species S. gobionis sp.nov., and on myxosporean life cycle stages in the blood of some freshwater fish

Abstract Freshwater fish in Czechoslovakia were examined for species of the genus Sphaerospora Thélohan, 1892 and for myxosporean life cycle stages in the blood. In addition to perch infected with S. pectinacea Bocharova & Donets, 1974, renal tubules of seven host species harboured thus far unidentified Sphaerospora species. A new species, S. gobionis sp.nov. is described from renal tubules of Gobio gobio. In populations of Gobio gobio, Tinea tinea and Rutilus rutilus harbouring infections with different Sphaerospora species, organisms identified as mobile myxosporean life cycle stages were detected in the blood, where they undergo a proliferative cycle. These organisms were reminiscent of stages in the blood of common carp fingerlings, supposedly identical with Sphaerospora renicola Dyková & Lorn. It is possible that the blood stages found in the three cyprinid hosts represent stages of the life cycle of their respective Sphaerospora species. If this is correct, further studies may show if the presence of proliferative stages in the bloodstream is a character distinctive of the genus Sphaerospora.     

Reproductive performance of fairy shrimp Branchinecta orientalis (G. O. Sars 1901) (Crustacea: Anostraca), fed with effluent of rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds

Aquaculture production is predicted to increase sharply. In this regard, live feed plays a crucial role in the larval phase of many aquaculture organisms. Hence, a persistent concern in aquaculture is to find low‐cost and eco‐friendly feed sources to culture live feed organisms. Branchinecta orientalis (G. O. Sars 1901), a fresh/brackish water fairy shrimp, was reared using effluent from rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds, either fresh but supplemented with two species of microalgae, Scenedesmus sp. and Haematococcus sp., or non‐supplemented but after “ageing” of the culture medium. The feeding experiment was designed at a density of 100 individuals L^?1 in 2‐L vessels. The results indicated that differences between final length, survival and most reproductive parameters of the treatment with aged medium and the treatment using fresh medium supplemented with Scenedesmus sp. were non‐significant (p > .05). Better results were obtained for a number of reproductive parameters in the treatment supplemented with Haematococcus sp. Thus, for intensive resting egg production of B. orientalis, microalgae can be replaced by aged non‐supplemented effluent from trout ponds as a nutrient‐rich feed source. This consequently can reduce drainage of nutrients into the environment and thus decrease aquatic pollution.     

Risk assessment of parasitic/symbiotic organisms of the commercially important mytilid Modiolus barbatus (Linnaeus, 1758)

A parasitological survey of the edible and commercially valuable mytilid horse‐bearded mussel (Modiolus barbatus Linnaeus, 1758) was carried out in the Mali Ston Bay, Adriatic Sea, in 2004 and 2005 to assess the potential effects of parasites/symbionts on this bivalve population. Data sets of abundance and prevalence were used to evaluate the structure and dynamics of infracommunities and component parasitic/symbiotic communities, along with evaluated histopathological changes, to assess the overall risk that these organisms pose to the mytilid. Based on moderate diversity indices and expected seasonal oscillation between the values of prevalence/abundance, parasitic/symbiotic fauna of M. barbatus was shown to be relatively stable, although moderately impoverished assemblages, dominated by two species, turbellarian Paravortex cardii and gregarine Nematopsis sp. Histopathological changes indicated only three species as pathogenic –Gymnophallus sp. sporocysts, Nematopsis sp. and a haplosporidian, although their pathological risk was assessed to be very low or low. From the epizootiological point of view, parasites are not a limiting factor for the successful introduction and farming of the M. barbatus.     

Effect of inoculation of the cyanobacteria Oscillatoria sp. on tilapia biofloc culture

Cyanophytes are the most ancient photosynthetic organisms. During its evolution, they have developed various ecophysiological adaptation strategies to survive in extreme conditions. The environment prevailing under biofloc cultures provides various conditions appropriate for cyanobacterial proliferation. An outdoor experiment (7 weeks) was performed with a simple random design consisting of four inoculation levels (by triplicate) of Oscillatoria sp. (0.0, 0.1, 0.5 and 1 mg L^?1) in saltwater biofloc. The objective was to evaluate the effect of the cyanobacteria inoculation on water quality and tilapia production parameters. The results indicated that the amount of Oscillatoria sp. inoculated significantly affected water quality (pH, chlorophyll a, TSS and NO₃‐N) and tilapia parameters (final weight, feed conversion ratio, specific growth rate and survival). No significant effects on dissolved oxygen, total ammonia nitrogen (TAN) or NO₂‐N were observed. We recommend identifying the cyanobacteria species that are able to grow in a biofloc system and their possible adverse effects on the system.     

鸡粪浆及5种微藻对轮虫脂肪酸组成的影响

采用投喂鸡粪浆的方法培养轮虫,并与5种微藻培养轮虫的脂肪酸组成进行了比较。结果表明:鸡粪轮虫具有较高的营养价值,HUFA含量达25.9%,仅次于小球藻轮虫和新月菱形藻轮虫,EPA和DHA的含量分别为11.2%和4.4%;在5种微藻培养的轮虫中,用小球藻、新月菱形藻和球等鞭金藻培养的轮虫营养价值较高,而用微绿球藻和衣藻培养的轮虫营养价值相对较低;轮虫的脂肪酸组成受饵料影响显著,但又不完全取决于饵料。     

光合细菌强化对精养鱼塘藻类群落结构的影响

通过定期向池塘投加光合细菌,研究了有益微生物强化对精养鱼塘浮游藻类群落结构的影响。结果显示:光合细菌强化塘(试验塘)藻类组成以绿藻、硅藻为主,养殖前期(5—6月初),以针杆藻、直链藻等占优势,中后期(7—9月)则以绿球藻、栅藻、盘星藻、小环藻、菱形藻等为优势种,水色呈淡绿、黄褐色等良好状态;而对照塘藻类组成在前期与试验塘没有明显差异,但在中后期出现明显变化,以微囊藻、颤藻、鱼腥藻、席藻等蓝藻占优势。试验塘藻类生物量显著低于对照塘(P<0.05),且对照塘生物量波动变化大,蓝藻数量所占比例可高达77.6%,远高于试验塘蓝藻比例(均值低于25.0%);此外,藻类Shannon-Wiener指数、Pielou指数试验塘均大于对照塘。结果表明:光合细菌的定期添加有效控制了蓝藻增值,保持了藻类多样性,使精养鱼塘藻相趋于稳定,有利池塘养殖。