大连紫海胆食性的研究——Ⅱ.幼海胆期饵料的初步探讨

大连紫海胆幼海胆期的食性开始由摄食单一的底栖硅藻变为多样化,对某些柔嫩的大型海藻(石莼,海带、裙带菜、江蓠)鱼虾贝肉等有机碎片以及人工配合饲料均表现出一定的嗜食性。幼海胆不但对不同种饵料的摄食率有差别,而且不同种饵料对幼海胆的饵料效果也有所不同,其中以海带和裙带菜的效果最好,幼海胆对其的摄食率分别为红藻、石莼、动物性蛋白饵料的1.2～2.3倍,而其饵料效率也分别为红藻,石莼等的1.1～1.4倍。幼海胆可摄食人工配合饲料将为其工厂化人工育苗开辟新的饵料来源。     

饵料对中间球海胆品质的影响

饵料种类对中间球海胆的品质有显著影响。长期摄食鲜海带或裙带菜的海胆生殖腺呈橘红色和橘黄色,摄食孔石莼为浅橘红色和橘黄色,摄食人工配合饲料为土黄色和乳白色。长期摄食鲜海藻类的海胆生殖腺味道甜美,口感上佳;而摄食人工配合饲料的则有苦涩味。饵料种类及其交替方式决定了海胆生殖腺色泽和口感的转变速度,其中鲜海藻类间转换速度基本一致,均需60d可完成;而人工配合饲料则需80d方能完成。中间球海胆消化道的颜色更易受饵料种类的影响,其转换速度与饵料种类和交替方式无关,20d即有明显表现,40d可完成。     

虾夷马粪海胆对饵料选择性研究

研究虾夷马粪海胆幼胆对鲜海带、盐渍海带、干海带、白菜和萝卜的饵料选择性。利用五种物料饲喂虾夷马粪海胆幼胆50天,检测海胆的成活率、生长情况。结果发现,摄食鲜海带和干海带组成活率最高,分别达到(99.83±0.29%)和(93.50±2.60%);摄食干海带和盐渍海带组的增重率最高,分别达到(120.36±3.13%)和(117.34土5.74%);摄食鲜海带和盐渍海带组的壳径扩增率最大,分别达到(4.74±0.45%)和(4.30±0.40%)。虾夷马粪海胆幼体摄食干海带时,饵料系数最低,为1.62±0.53。研究表明,鲜海带、干海带和盐渍海带都是虾夷马粪海胆的优选饵料。     

海藻渔用饲料中的应用

海藻是生活在海洋中含有叶绿素的一类低等单细胞自养植物，是海洋的初级生产者，能将海水中的无机物转化为蛋白质、脂类、糖类、维生素、有机酸等化合物。根据海藻中所含色素的不同，可将其分为绿藻（如石莼、溪菜）、褐藻（如马尾藻、裙带菜、海带）、红藻（如紫菜、江蓠）、金藻（如钙板藻）、蓝藻（如束毛藻）等１０类。目前，有记载的海藻约千余种，包括体长仅几微米的单细胞微藻到长达数百米的巨藻，其中有经济价值的达百多种，主要是褐藻、红藻和绿藻三大类。我国有广阔的海域以及漫长的海岸线，海藻资源颇为丰富，如海带的栽培面积及…     

中间球海胆的人工育苗及增养殖技术(之三)

(接上期)1 6　稚海胆的培育管理稚海胆生长发育阶段,由于摄食习性的转化,前后两个时期的管理要点与技术措施各不相同。1 6 1　前期培育:稚海胆前期以摄食(采苗板上的)底栖硅藻类为主,因此,本培育阶段的管理要点是设法提高采苗板上硅藻饵料的增殖速度,满足前期稚海胆摄食的需要,加速生长,提高育成率。具体管理措施是通过调整光照、加大换水量、适量充气、适度施加营养盐等手段,提高饵料硅藻的增殖速度。光照强度多控制在500～3000Lx之间,光照过强则绿藻繁殖过快,抑制硅藻的生长;光照过弱则影响硅藻的繁殖。在培育水体中保持适当的营养盐浓度…     

南方紫海胆摄食习性的初步研究

采用实验生态学的方法研究了成体南方紫海胆(Anthocidaris crassispina)的摄食和活力情况。结果表明,紫海胆在5种海藻共存的情况下,对不同海藻类具有不同选择性,日摄食率有显著性差异,对琼枝麒麟菜(Betaphycus gelatinum)的嗜食性最高,其次为半叶马尾藻(Sargassum hemiphyllum)、石花菜(Gelidium amansii)、石莼(Ulva lactuca),对刺松藻(Codium fragile)的喜好性较差。紫海胆的摄食受水温、海藻种类和自身体质量的影响,在23~27℃时活力和摄食状态最佳,水温升高和降低均会显著抑制其摄食;成体紫海胆对石莼、半叶马尾藻和琼枝麒麟菜的日摄食率有显著差异;在最适摄食水温下,紫海胆日摄食率随体质量增加呈显著的指数下降趋势。     

海藻在渔用饲料中的应用

海藻是生活在海洋中含有叶绿素的一类低等单细胞自养植物，是海洋的初级生产者，能将海水中的无机物转化为蛋白质、脂类、糖类、维生素、有机酸等化合物。根据海藻中所含色素的不同，可将其分为绿藻(如石莼、溪菜)、褐藻(如马尾藻、裙带菜、海带)、红藻(如紫菜、江蓠)、金藻(如钙板藻)、蓝藻(如束毛藻)等10类。目前，有记载的海藻约千……     

荣成俚岛斑头鱼摄食生态研究

2010年3月至2011年2月逐月采集荣成俚岛近海的743尾斑头鱼(Hexagrammos agrammus),探讨其摄食生态特征。结果表明,斑头鱼为底栖生物食性鱼类,摄食的饵料生物包括11个类群,主要摄食多毛类(Polychaeta),其次是鱼卵、海藻类、海草类、口足类(Stomatopoda)、端足类(Amphipoda)和鱼类等。食物组成随季节和体长而变化:除四季均大量摄食多毛类以外,春季还摄食口足类和虾类,夏季还摄食鱼类和蟹类,秋季还摄食鱼卵和鱼类,冬季摄食鱼卵比例最高;体长80 mm的斑头鱼喜食海草和海藻等植物性饵料,体长80~199 mm的个体喜食多毛类、鱼类和虾蟹类等,体长199 mm的个体主要摄食鱼类、多毛类和鱼卵等。摄食强度也随季节和体长而变化:夏季摄食强度最高,春季和秋季次之,冬季最低(不停食);体长100 mm的个体摄食强度最高,随着体长增加而逐渐下降,体长180 mm以上的个体又随体长和年龄的增大而逐渐升高。对斑头鱼5个饵料生物样品进行了DNA条形码鉴定,其中4个饵料生物样品鉴定到种,1个饵料生物样品鉴定到属。结论认为,斑头鱼的摄食习性会随季节、个体生长和栖息海域饵料生物的种类和丰度的不同而发生变化。     

桑沟湾底播养殖青蛤与魁蚶的食物来源

为了解底播养殖经济贝类青蛤(Cyclina sinensis)和魁蚶(Anadara broughtonii)的食物来源, 本研究通过稳定同位素技术和高通量测序技术测定了桑沟湾贝类区与贝藻区中底播养殖青蛤和魁蚶的食物组成, 分析了食物来源差异性的影响因素。结果显示: (1) 青蛤和魁蚶的食物来源主要是浮游植物(占比 40.4%~79.6%), 其次是浮游动物 (13.3%~37.3%)。贝类生物沉积物和海带碎屑对青蛤与魁蚶的食物贡献率存在区域性差异。贝类养殖区生物沉积物和海带碎屑对青蛤的食物贡献率为 2.7% (贝类生物沉积物 2.0%, 海带碎屑 0.7%), 对魁蚶的食物贡献率为 10.3% (贝类生物沉积物 7.4%, 海带碎屑 2.9%); 贝藻养殖区青蛤为 8.5% (贝类生物沉积物 5.1%, 海带碎屑 3.4%), 魁蚶为 7.4% (贝类生物沉积物 4.3%, 海带碎屑 2.1%)。(2) 青蛤胃含物中的主要成分是绿藻门(占比达 56.55%), 其次是链形植物门(44.35%), 魁蚶胃含物中的主要成分是绿藻门(47.27%), 其次是脊索动物门(30.3%)。两种贝类胃含物中的真核生物组成主要是浮游植物, 且主要来自于底层海水中, 与稳定同位素结果一致。(3) 在贝类区和贝藻区, 筏式养殖产生的有机物(生物沉积物和海带碎屑)对魁蚶的贡献率高于青蛤; 贝藻区海带碎屑对青蛤的贡献率高于魁蚶。从食源结构的角度比较分析, 魁蚶和青蛤均可作为桑沟湾综合养殖区域的底播贝类, 青蛤更适宜底播在有藻类养殖的区域。     

海藻食品的加工

海洋中的藻类约有1000多种，海藻按颜色分有褐藻、红藻和绿藻；我国沿海可供食用的海藻约50余种，主要栽培和食用最多的是紫菜、海带、裙带菜等。海藻富含蛋白质、矿物质、微量元素，特别是人体必需氨基酸的含量比其它动、植物原料多；而且味道鲜美，属纯天然食品。海藻还有医     

温度和藻类饵料对虾夷马粪海胆摄食及生长的影响

对虾夷马粪海胆石在１０．０－２５．０℃水温下单独投喂海带,裙带菜、石莼及１５．４－１７．８℃混合投喂海带、裙带菜、石莼、铜藻、角叉菜的不同组合和２１．６－２７．４℃饥饿状态下的摄食、生长及成活进行了试验研究。海胆体重与壳直径的关系为Ｇ＝０．４３１３２Ｄ＾２．９９５８。海胆对海带、裙采、石莼的日摄食率依次降低且随水温变化而异。１．０－３．６ｃｍ的纪海胆在１０．０－２５．０℃下摄食上述海藻均可保持较快     

水温和藻类对马粪海胆摄食、呼吸及排氨率的影响

在水温10.1℃,将初始体质量为(0.55±0.16)g的马粪海胆幼胆,随机放入0.3 m×0.4 m×0.5 m的白色塑料桶中,每桶100个,过量投喂新鲜孔石莼、粘膜藻、肠浒苔、裙带菜和珠状硬毛藻,计算各种藻类的摄食量(以干质量计),研究马粪海胆对藻类的摄食选择性。再将初始体质量为(0.67±0.32)g的马粪海胆置于水温为10.1、15.6、20.3℃的容器中,投喂相同的5种藻类2 d后,挑选10个规格相似个体放入1 L锥形瓶中,适应0.5 h后密封测定耗氧率和排氨率,研究不同温度和藻类饵料下马粪海胆的耗氧率和排氨率。试验结果表明,马粪海胆的摄食选择率依次为裙带菜>粘膜藻>孔石莼>肠浒苔>珠状硬毛藻,马粪海胆明显偏好裙带菜;马粪海胆摄食量受温度及藻类种类影响显著(P<0.05),在15.6℃时,日相对摄食率最大,摄食裙带菜的组别显著大于其他组别(P<0.05),摄食珠状硬毛藻的组日相对摄食率最低;各组别马粪海胆耗氧率均随着水温的升高而增大,相同温度条件下,孔石莼组耗氧率最大;各组排氨率随着水温的升高呈现先增大后减小,15.6℃时最大。研究结果将为开展马粪海胆生态增养殖、构建刺参池塘绿色综合养殖模式提供参考。     

Molecular identification of macroalgal fragments in gut contents of the sea urchin <Emphasis Type="Italic">Hemicentrotus pulcherrimus</Emphasis>

In order to improve the efficiency of stock enhancement programs for the sea urchin Hemicentrotus pulcherrimus, information on food algal species, which affect growth and gonad production greatly, is necessary. Since it is difficult to identify species from the macroalgal fragments within the gut contents of the sea urchin by microscopic observation, we tried to apply a DNA barcoding method for gut contents analysis. We used a partial rbcL gene sequence for taxonomic section and newly designed primer sets, respectively, for brown algae and for red algae. Direct sequencing of the PCR products was carried out. Species identification was based on the phylogenetic relationship. We could objectively identify four species and two taxonomic groups (genus or family) in brown algae, and two species and four taxonomic groups in red algae from the gut contents. Sargassum hemiphyllum was the most abundant brown alga in the gut contents but was not dominant in the study site. The result showed the importance of identification to the species level. In addition, red algal epiphytes were detected with brown algal fragments. The DNA barcoding method will enable the researchers to verify the important role of epiphytes as a potential food source.     

臭氧对海水的消毒及其在海胆育苗中的应用

通过不同的实验，证明臭氧对海水的消毒作用是高效和彻底的，处理后的海水完全能达到海胆育苗用水要求，可安全用于单胞藻的培养和稚海胆的培育，在冬季回收水的利用可极大地降低能耗，使海胆育苗成本大为降低。     

Agar‐based pellets as feed for sea urchins (Paracentrotus lividus): rheological behaviour,digestive enzymes and gonad growth

The algal polysaccharide agar has long been used as a food binder due to its structure, rheological behaviour, stability and interactions – properties that help to generate firm, round, disk‐shaped pellets that may be used in recirculating sea urchin‐rearing systems. Three algae‐based diets (Ulva lactuca, Gracilaria gracilis, Cystoseira sp.) containing 3% and 6% agar were tested on the sea urchin Paracentrotus lividus in order to examine the effect of varying percentages of agar on pellet stability in water and sea urchin gonad growth. The kinetics of water absorption and solute leaching of pellets were measured by immersing quadruplicate samples of the pellets in water for 1, 2, 3, 4, 5 and 6 days. Our results show that the pellets had good water stability, were readily consumed by sea urchins and the presence of agar did not hamper sea urchin gonad growth. Animals fed Ulva‐containing pellets reached a more advanced gametogenic stage with respect to animals fed Cystoseira‐ and Gracilaria‐containing pellets. Moreover, the presence of agarase activity in the digestive system indicated that agar may be an energy source. Pellets are relatively low cost and easy to prepare and store. They may represent a useful resource for rearing sea urchins under intensive conditions.     

Age distribution of the sea urchin Strongylocentrotus nudus (A. Agassiz) in relation to algal zonation in a rocky coastal area on Oshika Peninsula, northern Japan

ABSTRACT: The age distribution of the sea urchin Strongylocentrotus nudus in relation to algal zonation was studied in a sublittoral rocky area on Oshika Peninsula, northern Japan, from June 1995 through to August 1996. The algal zonation observed there extends from a shallow area of cobbles to deeper areas dominated successively by Sargassum yezoense , Eisenia bicyclis and, finally, crustose coralline red algae. One-year-old sea urchins occurred only on the cobbles and crustose corallines in contrast to the presence of 2-year-old individuals from all areas and the restricted distribution of individuals aged 3 years and over to Eisenia and crustose corallines. Calculated mean body sizes in the Eisenia area became larger after the age of 2 years compared with those in the area of crustose corallines. Spawning was ascertained histologically in both the Eisenia and crustose coralline areas, although gonad indices were higher in the former area than in the latter throughout the year. Gut contents were dominated by E. bicyclis in the Eisenia area, and by crustose coralline red algae and small algae in the crustose coralline area. Thus, the sea urchin may settle most abundantly on crustose corallines and lives there for 1–2 years. Thereafter, they expand their habitat toward the Eisenia area, where there is richer sources of food for attaining a higher growth rate and to generate heavier gonads.     

滁州鲫鱼食性的初步研究

对滁州鲫鱼的食性进行了调查研究。结果表明:滁州鲫是一种杂食性鱼,它的主要食物组成是轮虫、枝角类、桡足类、单胞藻类和有机碎屑等,随着体长的增长,食物中大型浮游动物、水生植物所占比例明显增加。对食物的摄食量上有季节性变化,在夏、秋两季摄食量最大,春季次之,冬季最少。     

An experimental assessment on the effects of photoperiod treatments on the somatic and gonadal growth of the juvenile European purple sea urchin Paracentrotus lividus

Determining the optimum light conditions for sea urchins reared in land‐based systems is vital for the future use and assessment of possible commercial systems of sea urchin farming. The effects of two different light regimes, complete darkness and a long day photoperiod of 16 h light:8 h darkness, on the somatic and gonadal growth of the European sea urchin Paracentrotus lividus (19.5–23.0 mm) was investigated using the commercial UrchinPlatter^? System over a 6‐month period (5 March to 5 September). Hatchery‐produced P. lividus were transported to the Aquaculture Fisheries Development Centre (AFDC, University College, Cork UCC). Before arrival at the AFDC, sea urchins were reared on a diet of Laminaria digitata. Females were the predominant species of the animal group, displaying a reproductive Stage III (growing stage) where gametogenesis was commencing. Results show that darkness supports higher somatic growth than the photoperiod treatment. Feeding rates were higher for sea urchins reared under darkness with gonadal growth increasing for both experimental treatments. Individuals reared under darkness had a higher per cent change in gonad index from the initial sample taken at the beginning of the experiment.     

Effect of Lipid Source and Concentration on Somatic Growth of Juvenile Green Sea Urchins, Strongylocentrotus droebachiensis

Supplying juvenile sea urchins with an abundant supply of resources and essential nutrients for growth will facilitate somatic growth and, hence, improve the success of the sea urchin aquaculture industry. Lipids are essential in physical processes such as membrane production and are a concentrated source of energy. This study, using prepared diets, tested the effects of lipid sources containing different major fatty acids (i.e., n‐3 and/or n‐6) (Part 1) and lipid concentration (i.e., 1, 3, 7, and 10%) (Part 2) on the somatic (i.e., test or shell) growth of two size cohorts (7.0‐ and 15.3‐mm average initial test diameter [TD]) of juvenile green sea urchins, Strongylocentrotus droebachiensis. The growth of the sea urchins fed prepared diets was compared to the growth of sea urchins fed a kelp reference diet, Laminaria longicruris. After both feeding trials, the kelp‐fed sea urchins had superior test growth and were more similar in physical appearance to wild sea urchins (i.e., test color, spine length, and gonad color). The sea urchins fed the prepared diets had pale test color, short, stubby spines, and large, pale‐colored gonads compared to wild sea urchins. The smaller cohort of sea urchins grew at a faster rate, but growth patterns for both cohorts were similar. The juveniles fed the prepared diets (in both feeding trials) had high initial growth rates that decreased after approximately 100 d compared to the kelp‐fed juveniles. Differences in test growth were not shown to be affected by sea urchin size (i.e., similar results for both cohorts) or by differences in dietary lipid sources (i.e., the presence of n‐3 and/or n‐6 fatty acids). However, the sea urchins fed diets with lower lipid concentration (≤3%) had larger average TDs than those fed diets with higher lipid concentrations (≥7%). Differences in test growth and physical appearance among those fed the prepared diets and kelp may have been because of nutritional deficiencies in the prepared diets.