Difference Between Tetrodotoxin and Saxitoxins in Accumulation in Puffer Fish Takifugu rubripes Liver Tissue Slices

In vitro accumulation of tetrodotoxin (TTX) and paralytic shellfish toxin (PST) in tiger puffer fish Takifugu rubripes was investigated using liver tissue slices. When T. rubripes liver slices were incubated with Leibovitz’s L-15 medium containing 0.13 mM TTX at 20 °C in air with saturated humidity, they accumulated 21.5 ± 7.3 μg TTX g⁻¹ liver after the incubation for 12 h and increased to 55.3 ± 8.2 μg TTX g⁻¹ liver at 48 h. In the incubation of T. rubripes liver slices with 0.13 mM PST-containing medium, PST was detected 6.3 ± 0.9 μg g⁻¹ liver at 12 h and reached a plateau thereafter. These results reveal the difference between TTX and PST in accumulation in T. rubripes liver tissue slices. To examine the variation in PST accumulation among fish species, the liver tissue slices from tiger puffer fish T. rubripes, parrot-bass Oplegnathus fasciatus and green ling Hexagrammos otakii were incubated at a concentration of 0.027 mM PST. The toxin contents of 3.0 μg g⁻¹ liver were observed at 8 h regardless of fish species but were not increased subsequently, showing no variety among these three species as to accumulation patterns of PST. It is noted that the tiger puffer fish T. rubripes liver specifically accumulate TTX in preference to PST.     

红鳍东方鲀3个白介素基因的序列特征及表达分析

本试验分析体质量(190.34±2.13)g的红鳍东方鲀白介素基因IL-1b、IL-8和IL-10的序列特征,检测其在红鳍东方鲀脑、鳃、心脏、肌肉、肝脏和脾脏中的表达,以及每尾红鳍东方鲀注射密度1×107 cfu/mL的哈维氏弧菌菌液0.1 mL后0、12、24、48 h在肝脏和脾脏中的表达.试验结果表明,IL-1b、...     

Tetrodotoxin accumulation conflicts with low salinity tolerance in juvenile tiger puffer Takifugu rubripes

We evaluated whether bearing tetrodotoxin (TTX) affects salinity stress in the juvenile tiger puffer Takifugu rubripes. Juveniles of hatchery-reared non-toxic T. rubripes [body weight (BW): 1.7?±?0.2 g, n?=?120] were divided into six tanks and acclimatized to salinity (8.5 ppt) that is equivalent to blood osmolality. Fish in three tanks were fed non-toxic diet, and those in the other three tanks were fed a TTX-containing diet (356 ng/g diet) three times a day until satiation. In each diet treatment, salinity of one tank was kept at 8.5 ppt, and the other two tanks were adjusted to either 1.7 or 34.0 ppt, and fish were reared for another 33 days. Then, we compared survival, growth, TTX accumulation, plasma osmolality, plasma cortisol, and glucose levels among treatments. We detected TTX only in the fish in the TTX-diet groups. Survival was highest at 8.5 ppt (70%) and lowest at 1.7 ppt in the TTX-diet group (20%). The BW was greater at 8.5 ppt, and plasma osmolality was significantly higher at 34.0 ppt than at any other salinities. Plasma cortisol level was significantly higher but glucose level was lower at 1.7 ppt. Possessing TTX at a low salinity may be lethal to tiger puffer juveniles.

     

养殖河鲀毒素控制技术研究

随着人们对河鲀毒素及河鲀的逐步认识和利用，养殖河鲀毒素控制技术研究日益成为人们关注的焦点，本文简要总结我们9年来在这方面所开展的一些工作以及日本等国在该领域的最新研究进展。     

5种微藻在红鳍东方鲀仔鱼培育中的效果研究

用5种富含EPA、DHA等高不饱和脂肪酸的海洋微藻强化褶皱臂尾轮虫、卤虫无节幼体,用强化后的轮虫和卤虫无节幼体投喂红鳍东方鲀仔鱼。结果显示:n-3HUFA(尤其是DHA、EPA)对提高仔鱼的成活率、生长率和耐高盐能力都有重要作用,DHA效果好于EPA,用EPA代替部分DHA是可行的,但过量的AA对仔鱼生长有抑制作用,并降低仔鱼的耐高盐能力。5种微藻中,H24、H61和H24 C95组效果较好,C95效果一般,B222、R165效果较差。     

Use of Defatted Soybean Meal and Blue Mussel Meat as Substitute for Fish Meal in the Diet of Tiger Puffer,Takifugu rubripes

A feeding experiment was conducted to examine the potential use of defatted soybean meal (SBM) and freeze‐dried meat of blue mussel (BM) as partial replacement of fish meal in the diet of tiger puffer. Eight experimental diets were formulated, in which 0, 20, 40 and 60% fish meal protein were replaced with SBM (S0B0, S20B0, S40B0, and S60B0), and 40 and 60% with a combination of SBM and BM (S30B10, S20B20, and S45B15, S30B30). Fish of 11 g initial body weight were fed the diets to satiation twice daily, 6 d/wk for 8 wk at 20 C. Specific growth rate, feed efficiency, and protein efficiency ratio (PER) of fish fed diets containing SBM as an alternative protein source for fish meal decreased with increasing level of SBM, and these parameters of fish fed S40B0 and S60B0 diets were significantly lower than those of the control. Growth of fish in dietary groups containing BM were statistically identical to those in the control, and tended to increase with increasing level of dietary BM both at 40 and 60% substitution levels. Growth and feed utilization of fish fed S20B20 were almost the same to those in the control.     

红鳍东方鲀稚鱼肠道可培养细菌的多样性

使用2216E平板涂布法从肠道样品分离可培养细菌,通过16S r DNA测序鉴定细菌。所有分离的细菌分为变形菌门(包含γ-变形细菌纲和α-变形细菌纲)和厚壁菌门。其中以γ-变形细菌纲为优势(83.3%)。在属的水平,从肠道中共分离出弧菌属、希瓦氏菌属、假交替单胞菌属、亚硫酸杆菌属、芽孢杆菌属、Aliivibrio、发光杆菌属、科尔韦尔氏菌属8个属,其中弧菌属、希瓦氏菌属和假交替单胞菌属的种类占总数的70%。首次发现亚硫酸杆菌属和科尔韦尔氏菌属作为红鳍东方鲀稚鱼肠道菌群的一部分。     

暗纹东方鲀Hepcidin基因的扩增及序列分析

利用聚合酶链式反应,首次从暗纹东方纯基因组DNA中扩增Hepcidin基因的部分序列,序列分析表明,不同鱼类之间的Hepcidin基因DNA序列之间的遗传距离为0.33～1.08,所获得的Hepcidin序列,为进一步研究暗纹东方纯中Hepcidin基因的作用机制提供了基础。     

苯并芘和V_E对红鳍东方鲀抗氧化酶影响研究

试验结果表明,当水中苯并芘质量浓度为50μg/L时,红鳍东方鲀的超氧化物歧化酶和过氧化氢酶酶活性显著低于空白对照组,最多分别低93.1%和35.4%。说明其体内抗氧化体系受到明显的抑制,且两种酶活性均表现出先抑制后升高的趋势,证明红鳍东方鲀对于苯并芘的胁迫具有一定的自我调节机能。给鱼体注射VE(3个缓解组剂量分别为10mg/尾、20mg/尾和30mg/尾)后,红鳍东方鲀的超氧化物歧化酶和过氧化氢酶酶活性都有一定的提高,表明VE对苯并芘的影响有缓解作用。     

红鳍东方鲀(Takifugu rubripes)雌、雄个体的形态特征比较

为了比较红鳍东方鲀(Takifugu rubripes)雌、雄个体的形态差异,基于主成分分析、逐步判别分析和T检验的方法,以红鳍东方鲀雌、雄群体的17个比例性状为分析对象进行研究.主成分分析构建了3个反映形态特征信息的综合性指标-主成分1、主成分2和主成分3,贡献率分别为46.776％、27.668％和7.122％,3个主成分累积的贡献率为81.566％,两个群体之间存在明显的偏离;判别分析结果显示,根据各变量对判别函数的贡献大小,筛选出两个比例性状,即体宽/体长、体周长2/体长,利用这两个性状建立起红鳍东方鲍的雌、雄判别模型,对雌、雄共72个个体的判别准确率为81.9％;T检验结果显示,体宽/体长在红鳍东方鲍两性群体间差异极显著(P＜0.01),体周长2/体长在红鳍东方鲍两性群体间差异显著(P＜0.05).综合分析实验结果表明,红鳍东方鲀雄性与雌性相比,体形较宽,体周长2较长.红鳍东方鲀雌、雄的形态差异为繁育和选育过程中的性别鉴定提供了新的方法和理论依据.     

Effect of Feeding Frequency, Water Temperature, and Stocking Density on the Growth of Tiger Puffer, Takifugu rubripes

Effects of daily feeding frequency, water temperature, and stocking density on the growth of tiger puffer, Takifugu rubripes, fry were examined to develop effective techniques to produce tiger puffer in a closed recirculation system. Fish of 4, 14, and 180 g in initial body weight were fed commercial pellet diets once to five times a day to apparent satiation each by hand for 8 or 12 wk at 20 C. Daily feeding frequency did not affect the growth of 14‐ and 180‐g‐size fish. However, the daily feed consumption and weight gain of the 4‐g‐size fish fed three and five times daily were significantly higher than those of fish fed once daily (P < 0.05). Fish of 4 and 50 g in initial body weight were reared with the pellet diet at 15–30 C for 8 wk. The weight gain of fish increased with increasing water temperature up to 25 C and decreased drastically at 30 C for both sizes. Similar trends were observed for feed efficiency, although 4‐g fish had highest efficiency at 20 C. Effects of stocking density on growth were examined with fish of 8, 13, and 100 g in initial body weight. Fish were reared with the pellet diet for 8 or 16 wk at 20 C. Fish were placed in floating net cages in the culture tank, and the stocking density was determined based on the total weight of fish and volume of the net cage. Fish of 8 g in body weight grew up to 35–36 g during the 8‐wk rearing period independent of the stocking density of 8, 15, and 31 kg/m³ at the end of rearing. Final biomass per cage reached 32, 60, and 115 kg/m³ for 13‐g‐size fish, and 10, 18, and 35 kg/m³ for 100‐g‐size fish, and the growth of the fish tended to decrease with increasing stocking density for both sizes.     

饲料中添加河豚毒素(Tetraodotoxine,TTX) 的河豚养殖

笔者试图通过对养殖红鳍东方过程中投喂添加河豚毒素的饲料提高其免疫力,降低鱼病发生率,还其自然野生状态下的本来面目,从而达到全面的健康化养殖。译出此文,供有关专业人员参考,并望有所启迪。     

Induced Ovulation in Obscure Puffer Takifugu obscurus by Injections of LHRH-a

Obscure puffer Takifugu obscurus (Abedate) is one of the several species of Takifugu genus that migrate to the Yangtze River, China during the spawning season of February to May. It is a popular fish among locals and fetches a premium price owing to its high-quality meat. It is also a potential species for intensive culture as its natural populations are currently declining. There have been no published studies on the effects of GnRH-a injection on the obscure puffer. In this paper, we report the results of several obscure puffer ovulation trials conducted in 1995 and 1996. We demonstrated that ovulation could successfully be induced in obscure puffer collected from open systems during spawning period using a dosage of LHRH-a as low as 40 µg kg^–1 in two injections. We found no significant differences among 80, 60, 40 µg LHRH-a kg^–1 treatments in ovulation success, egg production, fertilization rate and hatch rate. Accordingly, we recommend the use of 40 µg LHRH-a kg^–1 as the optimal dosage from an economical point of view.     

微卫星标记对红鳍东方鲀繁殖的指导应用及遗传分析

利用已有设计的20个具有多态性的微卫星标记对16尾红鳍东方鲀亲鱼(10尾♂,6尾♀)的有效等位基因数、观望杂合度、期望杂合度、多态信息含量、遗传相似性系数、遗传距离等进行了检测.据此设计了10对亲鱼配组,获得10个子代家系.其中母本中16和8号的平均有效等位基因数和平均期望杂合度较其他亲本高,将其分别与3个父本配组,其他则参照遗传距离进行配组.于次年,对F110个家系的体质量、体长均值进行了比对,发现16♀与11♂配组得到的子代体质量、体长均值为最大.8♀和10♂配组得到的子代体质量、体长均值最小.结果表明,红鳍东方鲀子代杂种优势与亲本个体差异有关.     

Growth of tiger puffer Takifugu rubripes in closed recirculating culture system

ABSTRACT:   Two feeding experiments were conducted to elucidate growth performance of tiger puffer in a 10 m³ water volume closed system. In experiment 1, 1000 fish of 3.5 g average body weight were fed tiger puffer commercial feed twice daily to apparent satiation, 6 days a week for 224 days. Sand-filtered sea water was used and no water was exchanged during the rearing period. Immediately after cutting of lower teeth at day 112, daily feed consumption decreased greatly and 60 fish died in few days. Feeding rates recovered and then decreased gradually as nitrate levels increased from 600–1048 mg N/L. Fish grew to 343 g with 91% survival rate and 87% feed efficiency. Rearing conditions of experiment 2 were similar to experiment 1, except that culture water was exchanged to maintain the nitrate level less than 600 mg N/L during the 224-day experiment. Mortality and reduction of feed consumption occurred immediately after teeth cutting as was observed in experiment 1. Significant reduction of feed intake was not found during other rearing periods. Fish of 3 g grew to 303 g with 91% survival rate and 72% feed efficiency.     

黄鳍东方鲀外周血细胞显微结构及血液学指标研究

血涂片经Wright染色液染色,可区分出:红细胞、血栓细胞、淋巴细胞、嗜中性粒细胞、单核细胞等5种血细胞,无嗜碱性粒细胞、嗜酸性粒细胞。白细胞中,血栓细胞数目最多,单核细胞数目最少。与其他硬骨鱼类相比,黄鳍东方鲀的血液性状指标处于较低水平;而雌雄差异不明显。结果可作为黄鳍东方鲀的正常生理常数参考值。     

红鳍东方鲀、菊黄东方鲀及其杂交F1幼鱼耗氧率与窒息点研究

利用封闭呼吸室对同一日龄、不同规格的红鳍东方鲀、菊黄东方鲀和菊黄东方鲀(♀)×红鳍东方鲀(♂)杂交F1代幼鱼进行耗氧率和临界窒息点的研究。试验结果表明,水温14.8～15.6℃时,体质量(37.24±3.64)g的红鳍东方鲀幼鱼耗氧率为(0.3385±0.0161)mg/(g.h),体质量(14.45±1.08)g的菊黄东方鲀幼鱼耗氧率为(0.2327±0.0241)mg/(g.h),体质量(27.96±1.38)g的杂交F1代东方鲀幼鱼耗氧率为(0.2282±0.0219)mg/(g.h);同一日龄不同规格红鳍东方鲀、菊黄东方鲀和杂交东方鲀幼鱼的耗氧量分别为(12.5243±0.6720)、(3.3544±0.2975)、(5.8469±0.9537)mg/(h.尾);3种东方鲀的耗氧率呈明显的昼夜节律,白天平均耗氧率显著高于夜晚。水温为14.8～15.6℃时,红鳍东方鲀、菊黄东方鲀及杂交东方鲀幼鱼的临界窒息点分别为0.665、0.882mg/L和0.774mg/L。     

红鳍东方鲀F_1代混养群体的基因型鉴定及QTL分析

利用微卫星标记的方法,分别对3个家系红鳍东方鲀的基因型进行鉴定,并通过此方法对3个家系混养后的混合群体进行区分,利用区分的结果与混合群体的生长性状指标进行QTL分析,结果为F0041中的基因型153/150,标记F0254中的基因型325/335,标记F0220中的基因型175/189,标记F0254中的基因型325/335与河鲀的体长、体质量表型值正相关,标记F0041基因型153/143,F0151标记中的250/250基因型,标记F0157中的基因型167/198,标记F0220中的基因型175/205与河鲀的体长、体质量表型值负相关.以期采用此方法能够为今后的亲子鉴定、个体识别及家系识别提供理论基础.