不同密度的石莼与中国对虾的混养实验

在10个水族箱(53cm×24cm×23cm)中各放养中国对虾(Penaeuschinensis)4尾,混养孔石莼(UluaPertysavar)0、4g、6g、8g和10g,采用投饲精养.结果表明,孔石莼能有效吸收N、P营养盐,提高对虾对饲料中氮的利用率(42.7%～212.9%),水质状况也优于单养对虾.混养的综合养殖指数高于单养对虾.对虾密度为320-480g@m-3,石莼密度为400～600g@m-3时,可以进行免充气养殖.     

PCR-DGGE指纹图谱技术分析发病龙须菜附生菌菌群组成

本研究以07-2品系龙须菜(Gracilaria lemaneiformis)为实验材料,提取自然条件下代表不同病变程度的健康、病间、白化藻体的附生菌DNA,经PCR扩增16S r DNA基因的V3可变区并进行变性梯度凝胶电泳(DGGE),分离V3片段,再对目的条带进行克隆鉴定。实验结果经数据化后计算龙须菜附生菌数目并比较附生菌菌群多样性,通过非度量多维尺度分析(n MDS)及多元梯度分析(RDA)来比较附生菌菌群组成相似性及优势菌群。实验结果表明,随着龙须菜病变程度的加深,附生菌菌落数及菌群多样性逐渐增加(P0.05)。n MDS分析结果表明,健康藻体与白化藻体在附生菌菌群组成上存在差异,病间藻体在附生菌菌群组成上与健康藻体更为接近。RDA分析结果表明,龙须菜健康藻体附生菌可能的优势菌群是海洋单胞菌属(Marinomonas),病间藻体附生菌可能的优势菌群是单胞菌属(Alteromonas)、红杆菌科(Rhodobacteraceae)、假交替单胞菌属(Pseudoalteromonas),白化藻体附生菌可能的优势菌未能鉴定到,而白化残留藻体附生菌鉴定到的优势菌有Maribacter、红杆菌科、玫瑰变色菌属(Roseovarius)。从上述结果可以看出,龙须菜健康藻体与发病藻体在附生菌菌群组成及优势菌上存在较大差异,而介于两者之间的藻体在菌群组成上更偏向于健康藻体。     

青岛沿海石莼属藻类暴发增殖的生物学调查与物种鉴定

2009年4月下旬～6月上旬,青岛部分内湾发生漂浮绿藻暴发性生长.本文系统调查了绿潮藻华发生的区域,以青岛湾为观测点估测了生物量,其高峰期生物量可达138 t.通过对漂浮绿藻的外观形态和显微结构观察,鉴定漂浮绿藻的样本为长石莼Ulva linza,但飘浮绿藻样本与固着生长的长石莼在形态结构上有明显的不同,主要表现为叶片宽大、细胞壁加厚.为确定其物种,作者克隆了漂浮绿藻的18S-28S rDNA转录间隔区序列(Internal Transcribed Spacer,ITS)和5S rDNA串联重复间隔区序列(5S rDNA Spacer Region,5SS),采用分子系统学方法确定漂浮绿藻样品为长石莼.本文首次报道了发生在青岛内湾的长石莼藻华,同时观察到了长石莼为适应漂浮生活在形态结构上发生的适应性变化,从而为阐释其发生机制提供依据.     

Influence of Ulva meal on growth, feed utilization, and body composition of juvenile Nile tilapia (Oreochromis niloticus) at two levels of dietary lipid

A nutrition trial was conducted to investigate the effects of dietary lipid levels and supplemental Ulva meal on growth performance, feed efficiency, nutrient utilization, and body composition of juvenile Nile tilapia, Oreochromis niloticus. Four isonitrogenous (CP 40%) diets containing 0% and 5% Ulva meal were formulated to contain 10% (low-lipid; LL) and 20% (high-lipid; HL) crude lipid. Triplicate groups of fish (~10 g) were fed to apparent satiation three times daily for 16 weeks. Fish fed 5% Ulva meal showed an increased growth performance (P < 0.05) compared with fish fed non-Ulva supplemented diets, irrespective of dietary lipid level. In particular, the incorporation of Ulva meal improved specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER). Feeding fish 5% Ulva meal diets resulted in significantly lower carcass lipid content. The results indicate that 5% inclusion of Ulva meal at both dietary lipid levels improves growth performance, feed efficiency, nutrient utilization, and body composition of Nile tilapia.     

The advantages of Ulva (Chlorophyta) as an additive in sea urchin formulated feeds: effects on palatability,consumption and digestibility

The present study was performed to determine whether the palatability, consumption and digestibility of an artificial sea urchin diet could be improved by the addition of a highly preferred seaweed. Four species of macroalgae (Ulva rigida, Ecklonia maxima, Porphyra capensis and Gigartina polycarpa) were assessed by pairwise preference tests. Each macroalgal species was consumed at least once by Tripneustes gratilla and significant preferences always involved Ulva as the most preferred species. Four protein‐rich artificial diets supplemented with varying amounts of Ulva [0, 50, 150 and 200 g kg^?1 designated 0, 5, 15 and 20U, respectively] were then developed and fed to urchins over a 20‐day period. Inclusion of 200 g kg^?1 dried Ulva significantly improved the palatability of the artificial diet and mean dry feed consumption rates were higher in urchins fed the 20U and 15U diets compared with urchins fed diets with a lower Ulva content. Daily digestible protein (DP) intake also differed significantly, with urchins fed the 20U diet having a significantly higher DP intake compared with the 15U, 5U and 0U treatments. These results indicate that inclusion of the palatable seaweed Ulva acted as a feeding stimulant, increasing the acceptability of the diets and boosting protein intake.     

关于海带“叶片点烂病”的初步研究

在自然界中,无论野生的或栽培的植物,都可能发生病害。海带(Laminaria japonicaAresch)也不例外。自开展人工养殖以来,几乎每年都有病害发生。1958年以前,大面积养殖生产还局限于水质肥沃的海区时,常常发生叶片绿烂病。1959年海带养殖在全国沿海推广以后,在水质瘠贫的海区,则常常发生各种白烂病。1959年5月和1960年4月,辽宁金县大     

中国沿海石莼属绿藻的ITS和5S rRNA序列分析

对采自2008年、2009年中国沿海的石莼属(Ulva)海藻进行了ITS基因间隔区序列和5S rRNA序列系统发育分析,探讨了绿潮藻的分类问题。根据ITS序列分析结果,绿潮藻中存在着几个不同的种,包括LPP复合体(Ulva linza-procera-prolifera)中的种类以及Ulva compressa。绿藻的5S rRNA序列系统分析结果的差异性较明显,但也在一定程度上印证了上述结论。根据本文中ITS基因间隔区及5S rRNA序列分析结果,本实验采集到的绿潮藻的后代中至少存在U.prolifera、U.linza和U.compressa三个种类。据此推断,我国黄海海域2008年、2009年爆发的绿潮中,存在上述三个种类。     

干出胁迫对孔石莼生长及生理影响

通过人工模拟干出条件研究孔石莼(Ulva pertusa)在不同干出条件下的生理生化反应。以采自大连潮间带的孔石莼为材料,测定在不同的干出时间(0 h、0.5 h、1 h、2 h、4 h、6 h)下其叶绿素a(Chla)含量、可溶性糖含量、脯氨酸(proline,Pro)含量、丙二醛(MDA)含量和过氧化物酶(POD)活性的变化。结果表明:干出胁迫会对孔石莼的生理生化过程产生明显的影响。随着干出时间的延长,孔石莼中叶绿素a含量呈现下降的趋势;丙二醛和可溶性糖的含量呈现缓慢的升高趋势;过氧化物酶活性和脯氨酸含量呈现明显的升高趋势。这些结果为孔石莼的抗性生理研究提供了补充和参考。     

Shelter effects of coralline algal turfs: protection for Turbo cornutus juveniles from predation by a predatory gastropod and wrasse

Laboratory experiments were conducted to examine the shelter effects of turfs of articulated coralline algae (ACA) for the Japanese spiny turban snail Turbo cornutus. The muricid gastropod Ergalatax contractus and the cockerel wrasse Pteragogus flagellifer were used as predators. When the muricid snail was used as a predator, the existence of ACA fronds improved the survival rate of the turban snail juveniles compared with the experimental treatment without ACA fronds. Refuge provided by ACA fronds against predation by the muricid snail was more notable for smaller-sized turban snail juveniles (5.8 mm in shell height) than those of a larger size (8.6 mm in shell height). In the experiment using the wrasse as a predator, a shelter effect was demonstrated for turban snail juveniles of two size groups (4.3 and 10.2 mm in shell height). ACA turfs hindered foraging by the wrasse, so the survival rate of the juveniles was greatly increased. No clear difference was observed between the two size groups of the turban snail in terms of the shelter effect of ACA turf. The shelter effect of ACA turfs for turban snail juveniles is thought to derive from the physical characteristics of the algae, which form a visual and physical barrier.     

失水干燥对紫菜等海藻光合作用、呼吸作用及生长的影响

室内晾干不同时间(2—12小时)四种海藻失水达90％。晾干2—12小时对紫菜的毛光合有促进作用。晾干7小时内对石莼的毛光合有促进作用,8小时出现抑制作用;晾干5小时内对礁膜的毛光合有促进作用,6小时出现抑制作用;不同时间晾干的孔石莼电光合均低于对照。晾干2—12小时,四种海藻的净光合速率均有下降,而呼吸作用均受到了不同程度的促进。     

Growth performance and feed utilization of Haliotis tuberculata coccinea (Reeve) juveniles from the Azores (north-eastern Atlantic Ocean): An assay of three mono algae diets

We assessed the dietary value of available seaweeds (Ulva lactuca, Ulva intestinalis, and Sargassum vulgare) as food for juvenile abalone Haliotis tuberculata coccinea. During the 6 weeks that the experiment lasted, initial shell length and weight increased from 13.95 ± 0.32 mm to 15.30 ± 0.30 mm and from 0.39 ± 0.02 g to 0.47 ± 0.03 g. Ulva lactuca diet resulted in higher shell growth rate (58.47 ± 16.76 μm day^?1), SGR (1.15 ± 0.47%.day^?1), weight gain (65.5% ± 33.3), and PER (1.56 ± 0.31), possibly thanks to its higher crude protein content. Both green algae (U. lactuca, U. intestinalis) prove to support the growth of H. tuberculata coccinea. However, they might not be appropriate for an optimal intensive aquaculture production; further research should be conducted to find more efficient diets for juvenile abalone.     

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。     

硇洲马尾藻人工育苗常见敌害生物及防治初探

本文调查了硇洲马尾藻人工育苗期间的主要敌害生物,并初步探讨了不同物理方法和化学药剂对其敌害生物的清除效果,旨在为人工育苗栽培提供基础资料。调查发现硅藻、刚毛藻、石莼、浒苔等附生藻类对硇洲马尾藻生长影响较大,蓝子鱼、麦秆虫和藻钩虾的摄食是硇洲马尾藻幼苗海区培育的主要危害。苗帘用5%硫酸铵药浴5min可抑制刚毛藻的生长,以2%柠檬酸药浴5min、0.3%醋酸药浴3min、3%硝酸铵药浴5min等均可药杀石莼、浒苔等附生绿藻,用640mg/L敌百虫浸泡10min可杀灭藻钩虾。     

海带对131I吸收的研究

本文介绍了海带对^131I的吸收试验。试验结果表明：海带叶片在光照条件下，24小时内，对^131I的吸收量要比黑暗条件下高33％左右，这似乎说明海带对^131I的吸收与光合作用有关。海带不同部位的藻块对^131T的吸收能力，以梢部为最大，中部次之，基部最小。不同浓度的Pb、Cu和尿素对海带吸收^131I的能力有影响。     

浒苔染色体制备及核型初步分析

由于浒苔染色体制备难度较大,至今还没有准确染色体数目及核型分析报道。以引发我国黄海绿潮优势种浒苔(Ulva prolifera)为研究对象,采用酶解-荧光法制备浒苔染色体,并比较分析染色体制备过程中秋水仙素预处理时间、酶解时间和滴片高度等3个关键因素对染色体制片效果的影响,以建立浒苔染色体制备方法。结果表明:用质量浓度为0.2%的秋水仙素处理12 h,染色体浓缩程度适宜,分散均匀,形态清晰;用质量浓度为2%的纤维素酶、果胶酶、离析酶,混合酶解20 h效果最好,能去除细胞壁、细胞膜和多糖物质;30 cm高度下滴片,能使细胞分散均匀,可以获得质量较高的浒苔染色体。核型分析显示,浒苔雌、雄配子体染色体数目为9条,孢子体染色体数目为18条。研究结果可为未来浒苔遗传特征分析以及浒苔功能基因定位研究奠定基础。     

The Spawning of Roach Rutilus rutilus (L.) in a Chalk Stream

Roach spawned on two sites where Fontinalis antipyretica (Hedw.) grew thickly on vertical pilings. The eggs were distributed throughout the fronds of Fontinalis but were concentrated near the water surface. The fish spawned on those parts of the sites where the current adjacent to the weed was relatively fast. The sudden drop in water levels caused by weed cutting presents a potential threat to spawning success.     

孔石莼的同形世代交替

通过实验室培养和显微观察,描述了孔石莼同形世代交替各个阶段的发育情况。雌雄异体的配子体成熟后,放散两鞭毛的配子,雌雄配子接合成合子进而发育成孢子体,孢子体成熟后放散四鞭毛的游孢子,游孢子固着后,可直接发育成配子体。其同形世代交替是单倍体的配子体与二倍体的孢子体相互交替。     

对有分枝长石莼(缘管浒苔)的研究

报道了有分枝的和气囊状的长石莼。在山东、江苏和浙江等地分别采集到了有分枝的长石莼,对有分枝的长石莼进行研究表明,分枝有两种情况:一种是真分枝,另一种是假分枝。同时研究了有分枝的长石莼的生活史,与无分枝长石莼的生活史相同,其生活史亦是单倍的配子体与二倍的孢子体相互交替的同形世代交替。在2008年度暴发的绿潮中采到了气囊状且具分枝的类似长石莼藻体,气囊状的结构可以使此类长石莼漂浮在海面生长。漂浮的绿潮藻成为生殖细胞的附着基质,大量的生殖细胞在囊状藻体上附着生长,可能成为黄海海域漂浮海藻泛滥的原因之一。     

大型海藻吸收氮磷营养盐能力的初步研究

将日本马泽藻Mazzaella japonica、孔石莼Ulva pertusa、鼠尾藻Sargassum thunbergii、红毛菜Bangia fusco-purpurea、蠕枝藻Helminthocladia australis、扇形拟伊藻Ahnfeltiopsis fla-belliformis6种大型海藻培养在富含氮磷海水中72 h,分析海水中氨氮、硝氮和活性磷浓度的变化,目的在于比较它们对营养盐去除效果。实验结果表明,6种海藻对氮磷都有明显的去除作用,日本马泽藻和孔石莼对氨氮、硝氮和活性磷的去除效果最好,分别吸收了培养水体中氨氮初始总量的98.0%和97.1%、硝氮初始总量的76.9%和82.0%、活性磷初始总量的90.8%和86.9%。     

Nitrogen dynamics in the settlement ponds of a small-scale recirculating shrimp farm (<Emphasis Type="Italic">Penaeus monodon</Emphasis>) in rural Thailand

Rural shrimp farmers in Thailand are being encouraged to adopt practices that will reduce the quantity and improve the quality of their effluent. A simple and cheap option for small-scale shrimp farmers is to use settlement ponds to store and remediate discharge water before being re-used. We undertook a detailed study of the settlement ponds in a small-scale commercial black tiger shrimp farm typical of rural Thailand. We found that over a 9-week period, following the harvest of one of the two farm production ponds, total nitrogen (TN) concentrations in the water column were reduced by 30%, with the greatest removal (56%) occurring during the fifth week. There was a 10% increase in dissolved organic nitrogen (DON) concentrations during the trial. Sediments were a source of total ammonia nitrogen (TAN), and the re-mineralisation rate was the highest in the first two settlement ponds. Coconut fronds added to two of the four settlement ponds to increase the surface area available for microbial activity were found to provide a site for microbial re-mineralisation of TAN, the photosynthetic uptake of TAN and oxidised nitrogen (NO _x ) and nitrification. The water column was a net assimilator of TAN through autotrophic uptake. This study has shown that settlement ponds are capable of reducing water column N concentrations; however, sediment must be managed to reduce re-mineralisation during successive cropping cycles. In addition, coconut fronds were shown to improve N removal, although they should be periodically removed to maintain efficiency.