Seasonal changes in biomass of macrophytes stranded on Yoro Beach along a sargassacean forest in Wakasa Bay,Sea of Japan

ABSTRACT:   Macrophytes stranded on a beach provide food and habitat for many kinds of animals and play important roles in coastal ecosystems. Macrophytes stranded on a sampling beach (56 m long) along a sargassacean forest (400 m long and 88 m wide) were collected every 10 days from late April 2003 to late May 2004. The weight of macrophytes stranded per meter of beach amounted to 1733 g dry wt/m per year. Sargassacean plants were dominant and constituted 72.9% (1263 g dry wt/m per year) of whole stranded macrophytes. Large numbers of macrophytes were stranded just after heavy winter storms and the maximum weight of stranded macrophytes in winter was 407 g dry wt/m. Stranded macrophytes also increased in May to July; the deterioration period of sargassacean species in this region, and the maximum weight in this period was 233 g dry wt/m. The number of sargassacean plants stranded with holdfast increased only in winter. These results suggest that winter storms have an important role in stranding sargassacean plants at Yoro Beach.     

鼠尾藻的繁殖生物学及人工育苗的初步研究

于2006年对大连沿海地区鼠尾藻Sargassum thunbergii的繁殖生物学进行了初步研究,并进行了鼠尾藻卵的采集及人工育苗试验.结果表明:鼠尾藻的繁殖期为6月中旬至8月下旬,水温为13～23 ℃,繁殖高峰期为7月中旬,水温为17℃,最大卵放散量可达300万粒/g;使用贝壳作为受精卵的附着基,在室内培育60 d后,鼠尾藻幼苗长度为2.5 mm左右;水温＜22℃时,幼苗生长较快,水温＞23℃时生长几乎停止.经过30 d海区暂养,幼苗的藻体长度达到7～8 mm.     

海藻/昆布粗多糖的经口亚急性毒性及影响肝药酶特性的研究

本研究从海藻/昆布药对临床应用的角度出发,以海藻/昆布药对的粗多糖组分为研究对象,探讨了药对粗多糖对大鼠的经口亚急性毒性以及对肝药酶活性的影响。通过试验设计,以雌雄各半SD大鼠连续经口给药2周不同剂量的药对粗多糖,记录给药期间大鼠生理状态和行为变化,末次给药后收集心、肝、脾、肺、肾等脏器做HE染色切片,光镜下观察组织病理学变化,并以探针底物体外温孵法测定给药后大鼠肝药酶活性变化。结果发现,给药后低剂量处理组[10.8 g/(kg·d)]和高剂量处理组[86.4 g/(kg·d)]大鼠的生理体征及脏器系数未见显著异常。在显微结构下,低剂量组各脏器形态基本正常,而高剂量组肝组织出现水肿、脂肪变及肝窦扩张,肺脏组织出现间质性炎症及气肿。低剂量组大鼠肝药酶活性未见异常,高剂量组肝药酶CYP3A4活性被显著诱导。由此推测,海藻/昆布粗多糖具有潜在细胞毒性,大剂量下可致肝、肺组织毒性损伤,并可能通过诱导肝药酶CYP3A4发生药物与药物的相互作用,最终影响药物的药效或产生不良反应等。     

Nutritional and Chemical Composition and Antiviral Activity of Cultivated Seaweed Sargassum naozhouense Tseng et Lu

Sargassum naozhouense is a brown seaweed used in folk medicine and applied for thousands of years in Zhanjiang, Guangdong province, China. This study is the first time to investigate its chemical composition and antiviral activity. On the dry weight basis, this seaweed was constituted of ca. 35.18% ash, 11.20% protein, 1.06% lipid and 47.73% total carbohydrate, and the main carbohydrate was water-soluble polysaccharide. The protein analysis indicated the presence of essential amino acids, which accounted for 36.35% of the protein. The most abundant fatty acids were C14:0, C16:0, C18:1 and C20:4. The ash fraction analysis indicated that essential minerals and trace elements, such as Fe, Zn and Cu, were present in the seaweed. IR analysis revealed that polysaccharides from cultivated S. naozhouense may be alginates and fucoidan. The polysaccharides possessed strong antiviral activity against HSV-1 in vitro with EC₅₀ of 8.92 μg/mL. These results demonstrated cultivated S. naozhouense has a potential for its use in functional foods and antiviral new drugs.     

饲料中用陆生植物淀粉替代鼠尾藻粉对仿刺参幼参生长和消化的影响

在实验室条件下研究了用不同陆生植物淀粉组合取代鼠尾藻粉饲养仿刺参Apostichopus japonicus幼参的生长效果。在试验1中,将平均体质量为4.19 g的仿刺参饲养在体积为45 cm×31 cm×30 cm的水槽中,投喂以鱼粉和大豆蛋白为蛋白源,以添加质量分数为30%鼠尾藻粉的作为对照饲料（F0组）,以添加质量分数为10%鼠尾藻粉并用不同比例陆生植物淀粉搭配取代20%的鼠尾藻粉作为试验组饲料（F1组,马铃薯、小麦、玉米、红薯各5.0%（质量分数,下同）;F2组,马铃薯、小麦、玉米、红薯、山药各4.0%;F3组,马铃薯、小麦、玉米、红薯、芋头各4.0%;F4组,马铃薯、小麦、玉米、红薯、山药、芋头各3.33%;F5组,马铃薯、小麦、玉米、红薯各3.33%、山药4.66%、芋头2.00%;F6组,马铃薯、小麦、玉米、红薯各3.33%、山药2.00%、芋头4.66%）。经60 d的饲养,结果表明,F4组仿刺参的特殊增重率最高。在试验2中,在相同容器和条件下饲养平均体质量为4.22 g的仿刺参,对照组饲料（F0组）同试验1,各试验组饲料是用不同比例陆生植物淀粉搭配并全部取代鼠尾藻粉（F1组,南瓜、木瓜、红薯、马铃薯各3.75%,芋头5.0%,其它10.0%;F2组,南瓜、木瓜、红薯、马铃薯各3.75%,芋头10.0%,其它5.0%;F3组,南瓜、木瓜、红薯、马铃薯各3.75%,芋头15.0%,其它0%）。经60 d的饲养,结果表明,F2组仿刺参的特殊生长率、肠淀粉酶活性和消化率分别比对照组提高123.81%、133.93%、10.42%～13.37%,差异极显著（P〈0.01）。用陆生植物淀粉取代鼠尾藻粉的饲料,可促进仿刺参生长的原因可能是其诱食作用和促进其消化吸收。     

鼠尾藻研究现状及发展趋势

鼠尾藻是我国沿海常见的一种经济褐藻,营养价值较高,藻胶含量少,是海参的最佳天然饵料。随着海参、鲍鱼养殖业的蓬勃发展,野生鼠尾藻的产量渐渐满足不了生产需求。鼠尾藻的人工育苗及养殖技术正在各地悄然兴起。鼠尾藻在医药、保健及化学工业等行业中又具有极大的开发潜力。综述了影响鼠尾藻生长、繁殖、营养等多种条件及关于鼠尾藻营养成分、种群遗传、人工育苗及养殖技术研究的最新进展,并提出了今后鼠尾藻的研究发展趋势,旨在为鼠尾藻产业的发展提供科学依据。研究亮点:分析鼠尾藻国内外研究现状,提出今后应大力开展鼠尾藻人工育苗技术,在此基础上开展鼠尾藻海上养殖及刺参池塘人工养殖。     

Immunomodulation and interferon gamma gene expression in sutchi cat fish,Pangasianodon hypophthalmus: effect of dietary fucoidan rich seaweed extract (FRSE) on pre and post challenge period

A 45‐days feeding trial was conducted to study the immunomodulatory effect and interferon gamma gene expression of dietary fucoidan rich seaweed extract (FRSE) from Sargassum wightii on Pangasianodon hypophthalmus fingerlings. One hundred and eighty fingerlings were distributed into six experimental groups in triplicates. Each group was stocked with 10 fish and fed to satiation with iso‐nitrogenous (34.96 ± 0.09–35.18 ± 0.03 CP%) and iso‐caloric (368.65 ± 0.86–375.09 ± 0.26 Kcal/100 g) purified diets containing either 0% FRSE (control), 1% FRSE (TF₁), 2% FRSE (TF₂), 3% FRSE (TF₃), 3% seaweed powder (TS₃) or 6% seaweed powder (TS₆) in the feed. After feeding trial the experimental fish were challenged with Aeromonas hydrophila. Immunological parameters like respiratory burst activity, lysozyme activity, phagocytic activity and total leukocyte count (TLC) were increased with the increasing level of dietary FRSE, whereas serum Albumin/Globulin (A/G) ratio and blood glucose level exhibited decreasing trend (P < 0.05). Increased TLC, blood glucose level, respiratory burst activity, serum A/G ratio, lysozyme and phagocytic activities were recorded during the post‐challenge period. Maximum expression of interferon gamma (IFN‐γ) gene was recorded in FRSE fed groups than the control group both in pre and post challenge condition. After challenged with A. hydrophila the highest survival was observed in TF₂ and TF₃ groups whereas lowest survival was observed in the control group. Hence, dietary supplementation of FRSE at an optimum level of 2% reduced the stress and improved the immune status of P. hypophthalmus fingerlings.     

环境因子对鼠尾藻生殖托生长及光合特性的影响

鼠尾藻(Sargassum thunbergii)样本采自青岛太平角, 以光照、温度、盐度及营养盐水平4项环境因子分别设置4组单因素实验, 研究其对鼠尾藻生殖托的生长、表观光合作用、暗呼吸作用以及色素积累的影响。结果显示: (1)光照度为8 000 lx、温度为20℃和盐度为20的条件下生殖托的比生长速率(SGR)较大, 表观光合作用较强。光照12 000 lx抑制生殖托的光合作用与生长, 15℃下比生长速率比20℃小50.64%(P<0.05), 盐度从31下降到28, 比生长速率与表观光合速率显著增大。(2)色素含量与光照度、温度呈显著的负相关性, 叶绿素a和类胡萝卜素含量受环境因子影响较大, 而叶绿素c相对稳定。(3)氮磷营养盐的浓度配比对生殖托的生长、光合作用影响显著, 适宜的氮磷比(N/P)范围为5∶1~1∶1, 而50∶1显著抑制生殖托的生长。(4)相比氮元素而言, 磷浓度变化对生殖托光合作用影响更大, 说明磷元素对于生殖托的构建至关重要。(5)氮磷比对生殖托色素含量影响不显著, 而富氮、富磷培养液有利于色素的积累。结果表明, 上述4项环境因子对鼠尾藻生殖托的生长及光合特性均有显著影响, 适宜的培养条件为光照度8 000 lx、温度20℃、盐度20、氮磷浓度比(N/P)在5∶1~1∶1。本研究旨在为鼠尾藻人工育苗技术的优化提供科学依据。

     

枸杞岛铜藻空间分布格局初探

为了查清铜藻空间分布格局与影响因子之间的关系,采用水下采样方法对不同生境条件下铜藻分布和生长情况进行了调查,并从大小两个尺度(站点间和站点内)分析了铜藻空间分布与影响因子之间的关系.结果发现,在站点尺度上,铜藻多集中分布于隐蔽的内湾处,分布密度和株高显著高于暴波站点(P＜0.05),暴波站点的波浪和水流运动大小以及浊度显著高于隐蔽站点(P＜0.05),说明暴波强度是影响铜藻水平分布和生长的主要因子之一;在站点内,铜藻垂直分布特征明显,潮间带低潮区铜藻分布密度和株高显著高于潮下带(P＜0.05),且分布在潮间带低潮区的藻苗平均株高最高;铜藻分布密度和株高与附着基粗糙度、坡度、坡向表现出一定的相关性,但经相关性分析表明,水深与铜藻分布密度最相关(r=-0.337,P=0.001),粗糙度次之(r=0.175,P=0.092),与坡度和坡向相关性不高,说明了与水深相关的光照条件可能是影响铜藻垂直分布和生长的另一个主要因子.研究表明,附着基物理特征不是影响铜藻分布的主导因子,由波浪和水流运动引起的沉积物再悬浮影响到铜藻所需的光照条件,进而影响到铜藻的分布与生长,以此推断出沉积物可能是影响铜藻空间分布格局的主导因子.     

几种海藻多酚对鱼类致病菌的抑菌性研究

用平板生长抑制法对角叉菜、海蒿子及鼠尾藻等藻体中的多酚化合物进行抑菌性试验,观察其对海神弧菌、巴西弧菌、徐氏弧菌、查格斯氏弧菌、鳗弧菌、波氏弧菌及哈维氏弧菌的抑菌效果。试验结果表明,不同来源海藻多酚对受试海洋弧菌的抑制能力具有显著的差异(P0.05);多酚含量越高,抑菌能力越强;多酚含量和多酚来源具有显著的交互效应(P0.05),随着多酚含量的增加,抑制差异显著增强;同一来源多酚对不同受试海洋弧菌的抑制差异性不显著(P0.05)。