Cytotoxic constituents in the holdfast of cultivated Laminaria japonica

ABSTRACT:     Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica . The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria.     

Mineral balance in Oreochromis mossambicus: dependence on magnesium in diet and water

Mozambique tilapia (Oreochromis mossambicus) confronted with magnesium shortage in water and diet, continue to grow, but develop magnesium deficiency, in particular when the diet is magnesium poor. Pronounced decreases in scale and vertebral bone magnesium content occurred within 8 weeks of magnesium deficient conditions and magnesium appears to be mobilized from scales and bone, probably to guarantee muscle magnesium homeostasis. Magnesium deficiency coincided with increased calcium and sodium content, and a low potassium content of the body. The slight, but significant, decrease in muscle magnesium concentration was accompanied by a marked increase in sodium concentration. Decreased tissue magnesium levels accompanied by high sodium levels were also observed for vertebral bone, but not for scales. An increased opercular chloride cell density was found in all experimental groups, but the branchial Na⁺/K⁺-ATPase specific activity was not affected. The prolactin cell activity was comparable in all groups. We conclude that magnesium deficiency leads to severe perturbations of the mineral homeostasis of hard, and eventually, soft tissues and that fish are less sensitive to such perturbations than higher vertebrates. The relation between magnesium deficiency and mineral balance may reflect the dependence of cellular ion transport mechanisms and cell membrane permeability to ions on magnesium.     

中国海区不同养殖品系海带与长海带之间的遗传关系

对中国海区海带(Laminaria japonica)不同栽培品系(种)及长海带(L.longissirna)的配子体无性繁殖系进行12个酶系统的同工酶检测,获得了31个基因位点,酶谱分析结果说明,来自同一株海带的雌、雄配子体无性繁殖系具有较高的遗传相似性,但“860”品系可能因杂合度大,导致该品系雌、雄配子体无性繁殖之间的遗传距离较远。对它们相应的亲本孢子体进行RAPD分析,30个随机引物共得到185个扩增位点,其中多态性位点76个,占41％。利用UPGMA对同工酶及RAPD所得到的遗传距离进行聚类分析,表明中国海区养殖海带的不同品系或品种之间的遗传相似性较大,而“烟杂1号”与长海带之间具有较近的亲缘关系。基于同工酶和RAPD图谱的结果推测,“烟杂1号”是一个新的杂交种,其母本可能是“荣杂1号”,而父本可能是长海带。     

极北海带对氮、磷吸收和砷、镉、铅吸附的研究

极北海带(Laminaria hyperborea)分布于大西洋东北海域,有很高的经济和生态价值,有望成为我国海藻资源增值的对象。本研究通过分析极北海带在不同温度下对N、P营养盐的吸收,以及对不同重金属离子的吸附,研究其对富营养化和重金属的去除能力。结果显示,1)温度为9℃~13℃时,极北海带对N、P的吸收率均最高,其中72 h后其对P的吸收率达到了95%~98%,对氨氮的吸收率为96%,对硝酸氮的吸收率约为42%,表明其对N、P有显著的去除作用。2)极北海带对As5+的富集量为168.33 mg/kg,藻体表面和内部As5+含量无显著差异,分别占藻体As5+总量的55%和45%,As5+处理6 d后极北海带的相对生长速率为–0.92%/d,极北海带生长不正常。极北海带对Cd2+的吸附量为15 mg/kg,且91%的Cd2+位于藻体表面,仅9%的Cd2+位于藻体内部,相对生长速率为5.78%/d,说明其对极北海带生长有抑制。极北海带对Pb2+的吸附量为320 mg/kg,其中96.5%的Pb2+被吸附于藻体表面,3.5%的Pb2+位于藻体内部,其相对生长速率为6.73%/d,表明Pb2+对极北海带的生长无显著影响。     

Potassium flux in juvenile striped bass (Morone saxatilis): influence of external concentrations of sodium chloride and calcium

Whole-body influx and efflux of K⁺ were determined for 25-day-old striped bass,Morone saxatilis, in conditions that simulated harvesting fish from ponds. During the first 5h in fresh water with combined high NaCl (80 mM) and low Ca²⁺ (0.12 mM) concentrations, a combination that is acutely lethal to this age of striped bass, K⁺ influx for fish in 0.07 mM K⁺ was 21±1.7 (SEM) compared to 3.4±0.33 nmol g^–1 h^–1 for fish in water with low Na⁺ (0.25 mM) or high Ca²⁺ (2.5 mM) concentrations. Influx of K⁺ was inhibited during the first few hours after fish were placed in flux chambers. Potassium efflux as percentage of⁴²K lost per hour was two-fold higher from fish in the high Na-low Ca treatment compared to fish in low concentrations of Na⁺ or high concentrations of Ca²⁺. Potassium efflux was probably much greater than influx, but exact values for efflux could not be calculated from the data available. Survival of fish in water with high Na-low Ca was not increased by addition of KCl to the water, indicating that the net loss of K⁺ was probably not the cause of death.     

基于MaxEnt模型预测极北海带在我国黄渤海的适生情况

我国黄渤海区域的自然藻场存在不同程度的退化,建立人工藻场是制止海底荒漠化、恢复海底植被和建设海洋牧场的重要手段。本研究模拟极北海带(Laminaria hyperborea)在我国黄渤海区域的适生情况,使用MaxEnt生态位预测方法,针对影响极北海带分部的21项关键水质及水文条件以及在原产地的分布情况,建立我国黄渤海海域生态位分布模型,划分相应的适生区域,并通过刀切法筛选对模型贡献度较大的环境因子,逐一分析其对极北海带适生性的影响。结果显示,在筛选出的9项对模型贡献度较大的环境因子中,温度与光照强度对极北海带分布的影响最大。极北海带在温度7℃～18℃范围、光强不超过52 E/(m2·d)的区间有较大的适生概率;氮、磷浓度对预测结果也有一定影响,但天然海水中的氮、磷浓度不足以成为极北海带分布的限制因子。总体来看,黄渤海区域有1.67%海域为中适生区,主要集中在辽东半岛东岸长海县附近海域;山东半岛东部、北部,渤海西北部有一定的低适生范围,占总海域面积的5.12%;非适生区和边缘适生区占海域总面积的88.51%和4.70%。本研究表明,辽东半岛东岸长海县附近海域是建立极北海带藻场的理想区域。     

Breaking seasonal limitation: year-round sporogenesis in the brown alga Laminaria saccharina by blocking the transport of putative sporulation inhibitors

Year-round induction of sporogenesis of Laminaria saccharina was performed by mechanically blocking the transport of the putative sporulation inhibitors produced by the blade meristem and culturing the plants in constant short days. Sporogenesis was successfully induced by removal of the blade meristem, either by cultivating distal blade fragments or by performing a transverse cut in the frond. The earliest sorus formation after artificial induction was 10 days. The age of the sporophytes used for induction was 6–11 months or 2 years in tank-grown or field-collected sporophytes, respectively. Zoospores were successfully released in all cases. Thus, by year-round artificial induction of sporogenesis, (1) sporeling production of L. saccharina and thereafter sporophyte cultivation could be achieved without seasonal limitation, and (2) the life cycle of L. saccharina (from spore to spore) could be completed within 8 months under controlled conditions.     

中国东南沿海青蟹属(Scylla)的种类组成

为调查青蟹属在中国大陆东南沿海的种类组成及明确优势种的种类,采集了13个地区共413只青蟹。通过形态比较,确认有4个种,它们是：锯缘青蟹（Scylla serrata）, 紫螯青蟹(Scylla tranquebarica), 拟穴青蟹（Scylla paramamosain）,榄绿青蟹（Scylla olivacea）。这4个种类可以从头胸甲额缘4齿的长度（FMSH/DFMS）、形状,螯足腕节内刺的有无、螯足及步足斑纹来区分。其中拟穴青蟹在中国大陆东南沿海分布最广,数量最多,其他3个种仅在海南和北部湾被发现。在拟穴青蟹中有9.7%的成熟个体和33.3%未成熟个体具有螯足内刺,因此不能仅凭借这个特征来鉴别拟穴青蟹。本文对青蟹属4个种的特征进行了描述并编制分种检索表。图2表4参26     

Supplementation of organic acids and algae extracts in the diet of red drum Sciaenops ocellatus: immunological impacts

The evaluation of a wide variety of immunostimulatory compounds in the diet of cultured fish has received heightened attention in recent years. However, two organic acids, polyhydroxybutyrate (PHB) and potassium diformate (KDF), have been researched to only a limited extent with aquatic species but have been shown to have various positive effects on terrestrial animals. Two algae extracts, carrageenan and alginic acid, also have been shown to elicit immunostimulation in some fish. Therefore, this study was conducted with red drum, Sciaenops ocellatus, as a model marine species to study the effects of organic acids and algae extracts as feed supplements by evaluating several humoral and cellular immune responses. A 7‐week feeding trial was conducted with disease‐free juvenile red drum (average initial wt. 2.6 ± 0.2 g). Semipurified diets were formulated to be isocaloric and contain 40% crude protein. Based on previous studies with other fish species, experimental diets were produced by supplementing the basal diet with KDF at 0.6%, PHB at 2%, alginic acid at 1% or carrageenan at 0.5% by weight in place of cellulose. Fish were stocked into 110‐L aquaria operated as a recirculating system with each diet assigned to three replicate aquaria containing 15 fish. At the end of 7 weeks, weight gain and feed efficiency were significantly (P < 0.0001) reduced in fish feed PHB compared to the basal diet and both algae extracts. The greatest phagocytic activity was found in fish fed the diet containing PHB. Total immunoglobulin level was higher in fish fed the diet supplemented with carrageenan. Goblet cell proliferation was greatest in the posterior end of the gastrointestinal tract but not different among dietary treatments. Organic acids and algae extracts evaluated in this study produced variable immunological responses in red drum with carrageenan showing the greatest potential as an immunostimulant.     

东海区红娘鱼属种类组成及其分布特征

根据1997—2000年东海底拖网渔业资源调查资料,分析了东海红娘鱼属Lepidorigla的种类组成和分布特征。调查中共出现7种：翼红娘鱼、贡氏红娘鱼、深海红娘鱼、岸上红娘鱼、日本红娘鱼、短鳍红娘鱼和斑鳍红娘鱼,其中深海红娘鱼、贡氏红娘鱼和短鳍红娘鱼为优势种类。7种红娘鱼主要分布于50～190m水深范围内,利用聚类分析的方法分析发现其分布可分为两种类型：110m以浅和110m以深海域,相似性分析(ANOSIM)表明这两个海域红娘鱼属组成存在明显的差异,分布于110m以浅海域的种类以翼红娘鱼和岸上红娘鱼为主,平均分布水深为87．9m和103．1m;分布于110m以深海域的种类以深海红娘鱼、短鳍红娘鱼、贡氏红娘鱼和日本红娘鱼为主,它们的平均分布水深为138．3m、130．5m、132．1m和128．5m。此外,还运用单因素方差分析方法(ANOVA)检验红娘鱼属各种类间底层水温和底层盐度非生物环境因子之间的差异显著性。     

Supplementation of potassium, magnesium and sodium chloride in practical diets for the Pacific white shrimp, Litopenaeus vannamei, reared in low salinity waters

The culture of Litopenaeus vannamei in inland low salinity waters is currently being practiced in various countries around the world. These environments are often deficient in key ions essential for normal physiological function, including potassium (K⁺) and magnesium (Mg²⁺). Farmers have sometimes been able to counteract ionic deficiencies in the water profile by adding mineral salts containing sources of K⁺ and Mg²⁺. The purpose of this study was to explore the possibility of correcting deficiencies of K⁺ and Mg²⁺ in the water profile with dietary supplementation of these minerals. Two separate 7‐week experiments were conducted in 4.0 g⁻¹ artificial low salinity water to evaluate the effects of mineral supplements (K⁺, Mg²⁺ and NaCl) to diets of L. vannamei reared in low salinity waters. In trial 1 seven diets were formulated (10 g NaCl kg⁻¹, 20 g NaCl kg⁻¹, 150 mg kg⁻¹ Mg²⁺, 300 mg kg⁻¹ Mg²⁺, 5 g K⁺ kg⁻¹, 10 g K⁺ kg⁻¹, and a basal diet to serve as a control). Minerals were added in the form of purified potassium chloride (KCl), magnesium chloride (MgCl₂·6H₂O) and NaCl. Trial 2 evaluated the use of a coating agent for the Mg²⁺ and NaCl treatments, while a K⁺ amino acid complex was utilized in the K⁺ treatments to reduce mineral leaching. Trial 2 was performed using similar treatment levels as trial 1. Shrimp survival and growth were assessed in both experiments. Results from trial 1 indicated no significant differences in survival, growth or percent weight gain. Results from trial 2 revealed no significant differences in survival and growth in the NaCl and Mg²⁺ treatments. However, significant differences in growth (P < 0.05) were observed when using the 10 g K⁺ kg⁻¹ treatment, suggesting that dietary supplementation of a K⁺ amino acid complex may help improve growth of the species in low salinity waters.     

A comparison of the use of different swab materials for optimal diagnosis of amoebic gill disease (AGD) in Atlantic salmon (Salmo salar L.)

Routine gill swabbing is a non-destructive sampling method used for the downstream qPCR detection and quantitation of the pathogen Neoparamoeba perurans, a causative agent of amoebic gill disease (AGD). Three commercially available swabs were compared aiming their application for timelier AGD diagnosis (Calgiswab^® (calcium alginate fibre-tipped), Isohelix^® DNA buccal and cotton wool-tipped). Calcium alginate is soluble in most sodium salts, which potentially allows the total recovery of biological material, hence a better extraction of target organisms’ DNA. Thus, this study consisted of (a) an in vitro assessment involving spiking of the swabs with known amounts of amoebae and additional assessment of retrieval efficiency of amoebae from agar plates; (b) in vivo testing by swabbing of gill arches (second, third and fourth) of AGD-infected fish. Both in vitro and in vivo experiments identified an enhanced amoeba retrieval with Calgiswab® and Isohelix® swabs in comparison with cotton swabs. Additionally, the third and fourth gill arches presented significantly higher amoebic loads compared to the second gill arch. Results suggest that limiting routine gill swabbing to one or two arches, instead of all, could likely lead to reduced stress-related effects incurred by handling and sampling and a timelier diagnosis of AGD.     

三种养殖鲟鱼卵营养成分的比较分析

对养殖施氏鲟（ Acipenser schrenckii）、西伯利亚鲟（ A.baerii）和小体鲟（ A.ruthenus）卵中常规营养成分、氨基酸（AA）和脂肪酸（FA）的组成和含量进行了测定。结果表明,三种鲟鱼中,西伯利亚鲟卵内粗蛋白（22.6％）和粗脂肪（17.9％）含量最高,且与施氏鲟的粗蛋白和粗脂肪含量都显著高于小体鲟（ P＜0.05）;三种鲟鱼卵内均含有18种氨基酸,其中必需氨基酸总量（ TEAA）占总氨基酸（ TAA）均高于49％,且施氏鲟卵内TEAA占TAA的50.06％,显著高于西伯利亚鲟和小体鲟（ P＜0.05）。三种鲟鱼卵内含量最多的必需氨基酸（ EAA ）均为亮氨酸,种类间的色氨酸含量差异显著（P＜0.05）,其他EAA含量无显著差异（P＞0.05）;各种非必需氨基酸（NAA）含量种类间差异不显著（P＞0.05）,以谷氨酸含量最高。三种鲟鱼卵内,含量最高的饱和脂肪酸（SFA）均为C16∶0,种间无显著性差异（P＞0.05）;单不饱和脂肪酸（MUFA）中均以C18∶1n-9含量最高,且施氏鲟卵内含量显著高于西伯利亚鲟和小体鲟（ P＜0.05）;多不饱和脂肪酸（ PUFA）中均以C22∶6 n-3含量最高,其中西伯利亚鲟卵内含量显著高于施氏鲟和小体鲟（ P＜0.05）;西伯利亚鲟卵内n-3/n-6值最高,小体鲟卵内最低,且三种鲟鱼间n-3/n-6值均有显著差异（ P＜0.05）。西伯利亚鲟鱼卵内, DHA、 EPA、 PUFA、 n-3 PUFA总含量及n-3/n-6值均显著高于另外两种鲟鱼卵（ P＜0.05）。因此,在配置鲟亲鱼配合饲料时,要重视各种脂肪酸之间的添加比例。     

Factors influencing growth of individual brown trout in three streams of the upper Midwestern United States

Growth rate variation of three age groups of brown trout, Salmo trutta L. (age‐0, 1 and 2, and 3+), was quantified from recaptured, individually tagged brown trout and related to season, stream reach, relative abundance, initial length and movement to examine factors influencing growth in length in three streams in the Midwestern United States. Total variation in growth was almost five times greater for age‐0 than for age‐3+ trout. Individual trout accounted for about 13% of total variation in age‐0 growth, season about 57%, and trout initial length and relative abundance combined another 2%. The 2006 age‐0 cohort had the fastest growth rates in their second spring and summer (2007) and slowest growth in their first winter (2006–2007). About 53% of total growth variation of age‐1 and age‐2 trout was accounted for by individual trout, season, initial length and stream reach. Predicted growth rates indicated strong effects of season and initial length. A significant interaction between these two factors indicated that, although smaller trout grew faster than larger trout, this length effect was most pronounced in spring and summer. About 35% of total growth variation of age‐3+ trout was accounted for by individual trout and season. Together, season and individual trout characteristics were identified as the most important factors influencing brown trout growth in these streams.     

几种海藻中溴过氧化物酶的筛选及酶学性质

溴过氧化物酶(BrPOD)是具有特殊功能的过氧化物酶,海藻是其主要来源。对几种中国海域的红藻如角叉菜(Chondrus ocellatus)、龙须菜(Gracilaria sjoestedtii)、珊瑚藻(Corallina officinalis)进行了溴过氧化物酶的藻种筛选,并对酶活较高的珊瑚藻进行溴过氧化物酶分离纯化及性质的研究。通过硫酸铵沉淀、DEAE-cellulose 52离子交换层析、Sephadex G-100凝胶层析等方法,从珊瑚藻中分离得到溴过氧化物酶。对该酶性质研究表明,该酶分子量较大,表观分子量为64 kD;溴化单氯甲酮的最适pH值为6.0;pH在5.0-9.0时酶活性稳定;在30-70℃温度范围内酶活性稳定;Ca2 、Co2 、Cu2 、Mn2 、NaF和EDTA等化合物使溴过氧化物酶活性下降,钒酸盐能提高酶活性。反应动力学实验表明,该酶对Br-、H2O2的Km分别为7.40 mmol/L和96.09μmol/L。     

三种大洋性柔鱼类营养成分和品质评价

为了探究阿根廷滑柔鱼、秘鲁茎柔鱼及巴特柔鱼的肌肉和皮营养成分与品质差异,采用国标法对其肌肉和皮的基本营养成分、脂肪酸组成和氨基酸组成进行测定分析,利用质构仪和低场核磁共振仪对其肌肉和皮进行了质构和水分分布分析。结果显示,阿根廷滑柔鱼肌肉的粗脂肪含量为1.23%,显著高于其他两种柔鱼（P<0.05）。除水分含量外,柔鱼肌肉的粗蛋白含量、粗脂肪含量和灰分含量均显著高于柔鱼皮（P<0.05）;柔鱼肌肉及柔鱼皮的不饱和脂肪酸含量均大于61%,阿根廷滑柔鱼肌肉的总不饱和脂肪酸ΣUFA为66.51%,显著高于其他两种柔鱼（P<0.05）;不同部位共检测出17 种氨基酸,其中柔鱼肌肉的必需氨基酸总量分别为5.54、6.68和5.97 g,占氨基酸总量的40%以上。柔鱼肌肉中不易流动水含量显著高于柔鱼皮（P<0.05）,阿根廷滑柔鱼肌肉的不易流动水比例最高,为96.92%。阿根廷滑柔鱼的硬度和弹性均显著高于其他两种柔鱼（P<0.05）,未去皮的柔鱼肌肉的胶粘性和黏附性显著高于去皮柔鱼肌肉（P<0.05）。与其他两种柔鱼相比,阿根廷滑柔鱼肌肉的不饱和脂肪酸含量高、质构特性好、保水能力强。去皮和未去皮的柔鱼肌肉在硬度、内聚性和咀嚼性方面没有显著差异（P＞0.05）,柔鱼皮的营养价值略低于肌肉,但仍具有较高加工利用前景。     

Changes in meat texture of three varieties of squid in the early stage of cold storage

ABSTRACT: The present study examined the changes in texture and protein components during cold storage of different squid varieties. Raw oval squid, Japanese common squid and arrow squid were sliced fresh and the muscles were stored at 4°C for 0, 4, 8, 12, 18, 24, 48 and 120 h. The rheological measurements, protein components and amounts of collagen were examined. The adhesiveness of each squid increased significantly in the early stage of cold storage. In all varieties, penetration decreased at 4 h, which is considered to be rigor mortis, then increased. The amounts of total collagen, 20°C water-soluble collagen and 70°C water-soluble collagen did not change significantly in each variety during cold storage. Sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE) pattern showed that the 580 kDa component gradually disappeared up to 48 h. The correlations between the amounts of 580 kDa component and adhesiveness or firmness were high. Models of fit based on chemical kinetics accurately expressed the behavior of adhesiveness, firmness and penetration showing that 63.2% of adhesiveness changes occurred in 13–19 h and that 63.2% of firmness changes occurred in 18–24 h.     

The evaluation of secondary stress response of grass carp (Ctenopharyngodon idella, Val. 1844) after exposing to the saline water

The stress response of grass carp to salinity was evaluated assessing the levels of hematocrit, leucocrit, plasma glucose, sodium, potassium and calcium. Mean hematocrit values increased following exposure to salinity. Mean leucocrit values elevated after exposure to salinity for 24 h, then decreased. Mean plasma glucose increased during saline exposure for 48 h and then decreased to normal values. Plasma sodium and chloride levels were increased to their highest values after 48 h. While plasma potassium value increased with the exposure time, plasma calcium values were not affected by salinity exposure.     

Effects of the protein/carbohydrate ratio of extruded diets on protein synthesis, protein growth and body composition in juvenile brown trout (Salmo trutta)

High levels of protein in fish feeds result in higher costs and nitrogen waste. Therefore, studies focused on protein substitution by alternative energy sources are necessary. Here we examine whether the protein:carbohydrate ratio in extruded diets affects protein-turnover parameters and the main tissue components in brown trout. Juvenile fish were adapted to two extruded diets: one higher in protein and lower in carbohydrate, C: 45/28 and the other higher in carbohydrate and lower in protein, HC: 37/40. Gross energy was 19 MJ kg⁻¹ DM in both diets. Protein and lipid digestibility were high and similar in both groups (≈90%), whereas total and carbohydrate digestibility and digestible energy were lower in the HC-fed group than in the C-fed group. Consequently, when fish were adapted to the diets, plasma levels of glucose and insulin differed between diets. HC-group presented higher plasma glucose levels and lower plasma insulin levels than C-group. Protein synthesis rates in white muscle, liver and whole body did not differ significantly between diets. In contrast, protein accretion rate of white muscle and whole body were significantly lower in the HC group, indicating an increase of protein degradation in these tissues and a decrease of synthesis retention efficiency. In spite of the daily protein intake of HC group was lower than C-group, the anabolic stimulation efficiency was increased by 34% in HC group. Protein and lipid contents in white muscle and liver were stable throughout the experiment. No hepatomegalia or increased fat deposition was observed in fish fed HC. Differences in specific growth rates (C: 0.88%; HC: 0.77%) were associated more with the lower protein consumption rate and the lower level of digestible energy in fish fed HC than with the higher dietary carbohydrate content of the diet.     

3种不同体色刺参体壁营养成分的比较研究

本研究分别对青色、紫色和白色刺参(Apostichopus japonicus)体壁的营养成分,包括蛋白、脂肪、粗多糖、氨基酸组成、脂肪酸组成及微量元素进行了比较分析.结果显示,青色刺参蛋白含量显著低于紫色和白色刺参(P<0.05),脂肪含量三者无显著差异(P>0.05),青色刺参和紫色刺参的粗多糖含量高于白色刺参(P...