温度对红鳍东方鲀幼鱼生长的影响

研究水温对鱼类生长影响,阐明最适生长温度及其机制,具有重大理论和实践意义。在鱼类的能量收支中,摄食是唯一的能量收入部分,在影响鱼类摄食量的诸多因子中温度和体重是最重要的两个。本试验设T=20℃、24℃、28℃、32℃四个温度梯度组,分两期进行：Ⅰ期研究在这四个不同温度下红鳍东方鲀幼鱼体重增长和全长增长的情况,Ⅱ期研究在这四个不同温度下不同体重红鳍东方鲀幼鱼对最大摄食量的影响。结果发现在Ⅰ期中当水温T=28℃时红鳍东方鲀幼鱼体重增长和全长增长最快,日增重率和日增长率分别为1.684,0.588。在T=20℃和T=24℃时体重和全长的增长率随温度的升高而逐渐增大,超过28℃时开始降低。在Ⅱ期试验中发现红鳍东方鲀幼鱼最大摄食量随体重的增大而增加,最大摄食量随温度的变化情况为：在试验水温为20～28℃范围内,二者呈正相关,超过28℃度时呈负相关。综合两期试验研究得出28～29℃是适合红鳍东方鲀幼鱼生长的最适温度。     

光谱对红鳍东方鲀幼鱼肠道微生物组成的影响

为探究光谱对红鳍东方鲀幼鱼肠道微生物组成的影响,以红鳍东方鲀幼鱼为研究对象,在5种不同光谱(蓝光、绿光、红光、白光、黄光)条件下对其受精卵进行孵化和饲育共90 d。试验结束后对各组幼鱼体长进行测定,采用Illumina HiSeq高通量测序技术对其肠道微生物的组成进行分析。结果显示,绿光组、黄光组和白光组的幼鱼体长显著高于蓝光组和红光组(P<0.05),且幼鱼存活率蓝光组>红光组>黄光组>白光组>绿光组。以相似度为97%的聚类分析显示,蓝光组、绿光组、红光组、白光组和黄光组的红鳍东方鲀肠道微生物的运算分类单元数分别为631、508、530、513、418个,共有运算分类单元数87个,特有运算分类单元数为0,但蓝光组和红光组共有的运算分类单元数为13。蓝光组Ace和Chao指数显著高于黄光组(P<0.05),即蓝光组的微生物菌群的丰富度最大,黄光组最小。蓝光组和红光组Shannon指数显著高于绿光组和黄光组(P<0.05),即蓝光组和红光组的肠道微生物菌群多样性大于绿光组和黄光组。属水平肠道菌群分布显示,弓形杆菌属、弧菌属、支原体等为红鳍东方鲀幼...     

红鳍东方鲀的人工繁殖试验

采用网箱养殖四年的红鳍东方鲀经过颗粒状的促黄体生成激素释放素(LH-RH)的植埋,促使性腺成熟,再通过注射绒毛膜促性腺激素(HCG)与大麻哈鱼脑垂体混合液诱导排卵,采卵后进行人工授精,得到红鳍东方鲀受精卵,孵化后得到红鳍东方鲀仔鱼。     

红鳍东方鲀人工育苗试验

采用网箱养殖四年的红鳍东方鲀经过人工促熟、人工催产、人工采卵和人工授精,孵化后取 10万仔鱼进行人工培育试验,经 50d培育,培育出平均全长为40.69mm,平均体重为1.78g的鱼苗3万尾,成活率约33.33％。     

双斑东方鲀与红鳍东方鲀杂交育种研究初报

为获得具有杂交优势东方鲀苗种,开展了双斑东方鲀与红鳍东方鲀杂交组、对照组人工繁殖及育苗;正交组(SH)、反交组(HS)胚胎发育观察;杂交组、对照组幼鱼耐高温试验。结果表明:正交组、反交组、双斑东方鲀子一代对照组(SB)、红鳍东方鲀子一代对照组(HQ)卵受精率分别为95.6%、93.5%、96.0%、89.5%,受精卵孵化率分别为92.2%、80.6%、89.4%、79.9%,室内育苗成活率分别为28.4%、18.7%、27.5%、19.2%;正交组(SH)池塘生态培育成活率为18.3%;在18.0~20.0℃水温条件下,正交组(SH)受精卵经132 h孵出仔鱼,反交组(HS)受精卵经164 h40 min孵出仔鱼;在28.0~35.0℃水温条件,反交组(HS)、对照组(HQ)幼鱼不能存活,正交组(SH)、对照组(SB)幼鱼正常生长;杂交子代生物学特性与母本相近,正交组(SH)可在福建、广东、海南等南方沿海地区推广养殖。     

温度对红鳍东方鲀能量收支和生态转化效率的影响

以玉筋鱼为饵料生物和最大摄食水平条件下,采用室内流水式实验,测定了不同温度下(13、16、19和25°C)红鳍东方鲀(平均体重为37.1±7.7g)的生态转化效率和能量收支各组分.结果表明,红鳍东方鲀的最大摄食率、吸收率、排泄能和总代谢能均随温度上升呈增长趋势.以湿重计算的特定生长率(SGRw)和生态转化效率(ECEw)则呈现先随温度增长而后下降的趋势,其与温度之间的关系可用二次方程描述.由回归方程计算出的特定生长率最大值出现在23.52℃,生态转化效率最大值出现在18.95℃.方差分析表明,红鳍东方鲀的能量分配模式随温度变化显著.排泄能分配率和代谢能分配率占摄食能的绝大部分67.8%～81.7%,随温度升高呈"U"形变化趋势,最低出现在16℃;生长能分配率则与之相反,最高分配率出现在19℃.不同温度下红鳍东方鲀的代谢能占了同化能的61.1%～73.5%,生长能占13.2%～23.2%.可见红鳍东方鲀基本上属于中等生长效率、中等代谢消耗型鱼类.     

红鳍东方鲀开口饵料筛选试验

本文选择水产育苗常用的幼体开口饵料──小球藻、轮虫、卤虫幼体、蛋黄对初孵红鳍东方进行开口饵料筛选试验。结果表明：用小球藻和轮虫混合投喂效果最好,其余依次为轮虫、卤虫幼体、蛋黄。     

红鳍东方鲀与假睛东方鲀的养殖对比观察

1996年6月～1997年6月,在基本相同的条件下对红鳍东方与假睛东方的生长速度、饲养成活率、体型与体态和行为习性等方面的差异进行了对比观察试验。试验结果表明,红鳍东方的生长速度比假睛东方快,饲养成活率比假睛东方高13．2％－15．6％。外部形态色泽较稳定,而假睛东方变异较大。红鳍东方平均游速为0．5m／s,集群游动性较强,假睛东方平均游速为为0．33m／s,性较凶残,体型较丰满。二者都具有广盐性,但都不适于长期在纯淡水中生存。二者的最适水温均为16－23℃。     

不同温度对红鳍东方鲀仔、稚、幼鱼形态发育和生长的影响

通过对三个不同水温的红鳍东方鲀育苗池的仔、稚、幼鱼的连续取样观察，分析比较在不同的培育水温对红鳍东方鲀的形态发育和生长的影响。通过试验分析表明，在红鳍东方鲀适宜的温度范围内的增温对红鳍东方鲀稚、幼鱼的影响效果明显，且不会降低成活率，从而可缩短育苗时间，降低成本，减少风险。     

饲料中淀粉和糊精对红鳍东方鲀生长和低氧耐受性的影响

在水产养殖鱼粉鱼油供应相对紧缺的背景下,充分挖掘碳水化合物(糖类)的营养功能具有重要意义。低氧是水产养殖中一种常见的环境应激。大量研究表明,鱼类在低氧条件下主要利用糖来提供能量,但饲料糖源对红鳍东方鲀(Takifugu rubripes)的生长和急性低氧耐受性尚未见报道。本研究分别在饲料中添加玉米淀粉或糊精(玉米淀粉水解物)作为糖源,养殖8周后,测定生长、急性低氧存活率、代谢产物和低氧诱导因子(HIF)信号通路等指标。结果显示,与淀粉组相比,糊精虽然不会影响红鳍东方鲀的生长性能和鱼体成分,但显著提高了其在急性低氧条件下的存活率。在常氧条件下,淀粉组和糊精组肝脏的糖原和乳酸含量均无显著差异(P>0.05),但在低氧条件下,糊精组肝脏的乳酸含量和乳酸脱氢酶基因表达量均显著高于淀粉组(P<0.05)。同时,糊精组肝脏hif-1α (hypoxia inducible factor 1 subunit alpha)和hif-3α (hypoxia inducible factor 1 subunit alpha, like)、肌肉hif-1α和vegfa (vascular endothelial growth factor A)的表达量均显著高于淀粉组(P<0.05)。在低氧条件下,糊精组血清甘油三酯(TG)含量显著升高,但淀粉组血清和肝脏的TG含量在低氧后却显著下降(P<0.05)。与常氧组相比,糊精组在低氧后的肌肉总蛋白含量、肝脏蛋白激酶B (v-akt murine thymoma viral oncogene homolog 1, akt1)和哺乳动物雷帕霉素靶蛋白(mechanistic target of rapamycin kinase, mtor)基因表达量均显著降低,但淀粉组肝脏的mtor基因表达在低氧后却显著升高(P<0.05)。综上所述,用易消化的糊精替代玉米淀粉激活了HIF信号通路介导的无氧糖酵解来为鱼体提供更多的能量,同时还可以抑制脂肪的分解和蛋白质的合成,减少了O2的消耗,从而提高了红鳍东方鲀对急性低氧的耐受性。本研究结果为鱼类耐低氧饲料的设计和健康养殖提供了重要参考。     

红鳍东方鲀对8种饲料原料的表观消化率

本研究旨在探讨红鳍东方鲀(Takifugu rubripes)幼鱼对红鱼粉、白鱼粉、豆粕、菜粕、花生粕、棉粕、玉米酒糟蛋白(DDGS)和肉骨粉中干物质、粗蛋白、粗脂肪、氨基酸、总能和总磷的表观消化率.实验饲料由70％的基础饲料和30％的待测饲料原料组成,并添加0.1％的三氧化二钇(Y2O3)作为外源添加剂,选取平均体重...     

Histopathological studies on Vibrio harveyi– infected tiger puffer,Takifugu rubripes (Temminck et Schlegel), cultured in Japan

Vibrio harveyi infection occurred with a moderate mortality in tiger puffer, Takifugu rubripes (Temminck et Schlegel), in autumn 2007, at a mariculture farm in western Japan. The diseased fish showed nodular lesions in the branchial chamber and the inner surface of the operculum. Histopathologically, the lesions comprised granulation tissue containing many suppurative foci allowing propagation of the bacteria and granuloma encapsulating abscesses with a decrease in bacteria. The bacteria were disseminated in visceral organs including the spleen, kidney, liver, and myocardium, resulting in the formation of granulomatous lesions. Two groups of tiger puffer juveniles were artificially infected by an intramuscular injection with an isolate (1.0_10⁸ CFU/fish). During the experimental period, 20% mortality occurred within 4–6 days post‐infection (d.p.i). The fish sampled on 4 d.p.i showed abscesses in the lateral musculature at the injection site. The fish sampled 5 d.p.i. displayed the production of granulation tissue containing many suppurative foci, which replaced the necrotic dermis and lateral musculature. Surviving fish (15 d.p.i.) had granulomatous lesions in the lateral musculature at the injection site. Pyogranulomatosis is pathognomonic in V. harveyi infection of tiger puffer.     

Pathological changes induced by three myxosporeans in the intestine of cultured tiger puffer, Takifugu rubripes (Temminck and Schlegel)

Pathological changes in cultured tiger puffer, Takifugu rubripes , with emaciation disease in Kyushu, Japan were studied histologically. In most cases, diseased fish were heavily infected with at least one of three myxosporeans ( Myxidium fugu , Myxidium sp. and Leptotheca fugu ) and two unidentified hyperparasitic microsporeans, attached to, or in, the intestinal epithelium. Myxidium fugu attached to the surface of the epithelium, caused no noticeable effects on the host tissue, irrespective of its infection with the hyperparasite. Myxidium sp., which proliferated in the epithelium, induced severe pathological changes including accumulation of cell debris between the epithelium and lamina propria and resultant detachment of the epithelium. Leptotheca fugu, another histozoic myxosporean, induced degeneration of the epithelium, associated with massive infiltration of macrophages into the epithelium to encapsulate parasites. When L. fugu was infected with its hyperparasitic microsporean, shortened villi were also observed. This is probably because passage of macrophage-parasite aggregates through the basement membrane of the epithelium severely damaged the epithelial structure. It is evident histologically that, unlike epicellular M. fugu , histozoic Myxidium sp. and L. fugu with or without hyperparasitic microsporeans, were highly pathogenic to host fish. This strongly suggests that they are causative agents of the emaciation disease.     

Temperature effects on the development of Enteromyxum spp. (Myxozoa) in experimentally infected tiger puffer, Takifugu rubripes (Temminck & Schlegel)

The effects of water temperature on the development of the enteric myxosporeans, Enteromyxum fugu and Enteromyxum leei, were investigated in experimentally infected tiger puffer, Takifugu rubripes. After naïve tiger puffer were fed gut tissue infected with both E. fugu and E. leei, they were divided into separate tanks and kept at different constant temperature regimes between 10 and 25 °C. Regardless of the water temperature tested, E. fugu was consistently detected with a high prevalence of infection (60–100%), although no sporulation occurred at 10 and 15 °C. Development of E. leei and the onset of disease were suppressed by low water temperatures (<15 °C). However, a temperature increase to 20 °C promoted the development of E. leei, followed by an increase of disease rate in the fish. The present study demonstrates that water temperatures below 15 °C have an inhibitory effect on the development of E. fugu and E. leei, resulting in suppression of enteromyxosis at low temperatures.     

Effects of dietary protein to energy ratios on growth and body composition of juvenile Japanese seabass, Lateolabrax japonicus

A growth experiment was conducted to determine the optimal dietary protein to energy (P/E) ratio for juvenile Japanese seabass (initial average weight 6.26±0.10 g). Nine practical diets were formulated to contain three protein levels (36%, 41% and 46%), each with three lipid levels (8%, 12% and 16%), in order to produce a range of P/E ratios (from 19.8 to 28.6 mg protein kJ⁻¹). Each diet was randomly assigned to triplicate groups of 60 fish in sea floating cages (1.5×1.5×2.0 m). Fish were fed twice daily (06:30 and 16:30) to apparent satiation for 8 weeks. The water temperature fluctuated from 26.5 to 32.5 °C, the salinity from 32‰ to 36‰ and dissolved oxygen content was approximately 7 mg l⁻¹ during the experimental period. The results showed that the growth was significantly affected by dietary P/E ratio (P<0.05). Fish fed the diets with 46% protein (12% and 16% lipid, P/E ratio of 26.7 and 25.7 mg protein kJ⁻¹) had the highest specific growth rates (SGR) (4.26 and 4.24% day⁻¹). However, fish fed the diet with 41% protein and 12% lipid showed comparable growth (4.20% day⁻¹), and had higher protein efficiency ratio (PER), protein productive value (PPV) and energy retention than other groups (P<0.05). No significant differences in survival were found among dietary treatments. Carcass lipid content positively correlated with dietary lipid level irrespective of protein level and inversely correlated with carcass moisture content. Carcass protein and ash contents increased with increasing dietary lipid at each protein level. These results suggest that the diet containing 41% protein and 12% lipid with P/E of 25.9 mg protein kJ⁻¹ is optimal for Japanese seabass.     

Effects of the dietary protein to energy ratio on growth,feed utilization and body composition in Macrobrachium nipponense

Oriental river prawn (Macrobrachium nipponense) has been widely cultured in Asian countries. However, its nutritional studies are very limited. In the present 8‐week study, we investigated the effects of dietary protein to energy ratio (P/E ratio) on the growth, feed utilization and body composition in juvenile M. nipponense (initial weight 0.302 ±0.03 g). Two‐factor experiment was designed and nine semi‐purified diets were formulated to contain three lipid levels (20, 80 and 140 g kg^?1) and three protein levels (330, 380 and 430 g kg^?1), producing P/E ratios from 16.5 to 23.4 mg KJ^?1 protein. The results indicated that the growth, survival rate and protein efficiency were dose dependently improved by the increased dietary lipid, but not dietary protein content. Increased dietary lipid content and/or protein content increased lipid accumulation in whole body, hepatopancreas and muscle, but did not change the feed intake and hepatopancreas weight. In conclusion, our present study indicated that M. nipponense is a species with relatively high‐energy requirement. It could utilize dietary lipid content up to 140 g kg^?1, while the dietary protein with more than 330 g kg^?1 would not promote growth and protein efficiency. Taken together, 330 g kg^?1 dietary protein and 140 g kg^?1 dietary lipid level with P/E ratio 16.49 could be optimum for M. nipponense.     

Effects of dietary protein to energy ratios on growth and body composition of juvenile Chinese sucker,Myxocyprinus asiaticus

A growth experiment was conducted to investigate effect of dietary protein to energy ratios on growth and body composition of juvenile Myxocyprinus asiaticus (initial mean weight: 10.04 ± 0.53 g, mean ± SD). Nine practical diets were formulated to contain three protein levels (340, 390 and 440 g kg^?1), each with three lipid levels (60, 100 and 140 g kg^?1), in order to produce a range of P/E ratios (from 22.4 to 32.8 mg protein kJ^?1). Each diet was randomly assigned to triplicate groups of 20 fish in 400‐L indoors flow‐through circular fibre glass tanks provided with sand‐filtered aerated freshwater. The results showed that the growth was significantly affected by dietary P/E ratio (P < 0.05). Fish fed the diets with 440 g kg^?1 protein (100 and 140 g kg^?1 lipid, P/E ratio of 31.43 and 29.22 mg protein kJ^?1) had the highest specific growth rates (SGR) (2.16 and 2.27% day^?1, respectively). However, fish fed the diet with 390 g kg^?1 protein and 140 g kg^?1 lipid showed comparable growth (2.01% day^?1), and had higher protein efficiency ratio (PER), protein productive value (PPV) and energy retention (ER) than other groups (P < 0.05). No significant differences in survival were found among dietary treatments. Carcass lipid content was positively correlated with dietary lipid level, but irrespective of protein level and inversely correlated with carcass moisture content. Carcass protein contents increased with increasing dietary lipid at each protein level. The white muscle and liver composition showed that lipid increased with increasing dietary lipid level (P < 0.05). Dietary protein concentrations had significant effect on condition factor (CF), hepatosomatic index (HSI) and viscerosomatic index (VSI) (P < 0.05). However, dietary lipid concentrations had no significant effect on CF, HSI (P > 0.05). Based on these observations, 440 g kg^?1 protein with lipid from 100 to 140 g kg^?1 (P/E ratio of 29.22 to 31.43 mg protein kJ^?1) seemed to meet minimum requirement for optimal growth and feed utilization, and lipid could cause protein‐sparing effect in diets for juvenile Chinese sucker.