不同海藻磨碎液对栉孔扇贝性腺发育及增重效果的比较

为了研究不同海藻磨碎液在栉孔扇贝暂养阶段的摄食效果,通过投喂微绿球藻(Nannochloropsis sp.)、孔石莼(Ulva pertusa)、孔石莼+微绿球藻、角叉菜(Chondrus ocellatus)、角叉菜+微绿球藻、裙带菜(Undaria pinnatifida)、裙带菜+微绿球藻七组不同的天然海藻饵料来对栉孔扇贝的性腺发育和增重进行评价。30d的对比实验结果显示:投喂孔石莼+微绿球藻的栉孔扇贝性腺指数增长量为0.036±0.002,显著高于其余饵料组(P0.05);其增重率为53.4%±6.3%,均显著高于其余饵料组(P0.05)。对比结果显示,孔石莼+微绿球藻饵料处理组能有效促进栉孔扇贝性腺发育和增加软体部的重量,在扇贝育苗中可作为替用饵料与单胞藻混合使用。     

几种营养强化材料应用于拟穴青蟹种苗培育的初步研究

进行了以淡水小球藻粉、虾片、营养强化剂单一或组合形式替代微绿球藻作为n-3高度不饱和脂肪酸供应源培育拟穴青蟹蚤状Ⅰ期幼体(Z1)~大眼幼体(M)的试验。结果表明:(1)轮虫营养强化后高度不饱和脂肪酸均有显著提高,微绿球藻组与其他组强化轮虫的n-3HUFA含量无显著差异。(2)卤虫不同营养强化材料组中,50μL营养强化剂组有最高的20∶4n6(ARA)、20∶5n3(EPA)、22∶6n3(DHA)、n-3HUFA含量。(3)营养强化材料直接投入苗池。上午投喂0.5×10-6g/mL组合饵料,下午投喂0.5×10-6g/mL营养强化剂,辅以10×10-6g/(mL.d)EM活菌,试验池的M成活率比对照池投喂微绿球藻增加了10.1%。     

自溶面包酵母在马氏珠母贝育苗中的饵料效果

在实验车间内利用120L的塑料箱作为实验容器,采用自溶面包酵母(Saccharomyces cerevisiae)作为单细胞藻的辅助饵料,研究其在马氏珠母贝(Pinctada martensii Dunker)育苗中的饵料效果,以期解决该贝育苗过程饵料供应不稳定、易培饵料品种小球藻(Chlorella sp.)利用率低的问题。研究结果表明:(1)在温度(30.0±0.5)℃、NaCl质量分数3%、pH6.5～7.0的自溶条件下,用经过18h自溶的酵母投喂D形幼虫,其平均日壳长增长率显著高于其他自溶时间酵母投喂组效果,单独投喂非自溶酵母时D形幼虫不能存活;(2)D形幼虫期单投自溶酵母,幼虫成活率与金藻组没有显著差异(P>0.05),生长速度比金藻组提高8%(P<0.05),说明自溶酵母可以完全替代湛江等鞭金藻(Isochrysis zhanjiangensis Hu﹠Liu),但在壳顶幼虫期和稚贝期单投自溶酵母不能使幼虫和稚贝正常发育和存活;(3)壳顶幼虫期及眼点幼虫至稚贝期投喂"自溶酵母 小球藻(Chlorella sp.)"或"自溶酵母 扁藻[Platymonas subcordiformis(Wille)]",其生长速度及存活率或稚贝育成率均显著高于单投扁藻或小球藻(P<0.05),单投小球藻的饵料效果最差;(4)自溶酵母与小球藻混投对眼点幼虫至稚贝培育效果较单独投喂影响显著,可显著(P<0.05)提高稚贝的育成率、生长速度和耐干露能力。研究表明,使用自溶酵母可以优化马氏珠母贝健康苗种规模繁育中的饵料供应工艺及提高易培饵料品种小球藻的利用价值,从而提高该贝育苗效果。     

不同海藻磨碎液对两种扇贝生长发育的影响

为研究不同海藻如孔石莼(Ulva pertusa)、角叉菜(Chondrus ocellatus)和裙带菜(Undaria pinnatifida)碎屑对栉孔扇贝(Chlamys farreri)和虾夷扇贝(Patinopecten yessoensis)在暂养阶段的生长和发育的影响。用海洋微藻——微绿球藻(Nannochloropsis sp.)作为对比和混合性饵料,7种饵料组分别为微绿球藻、孔石莼碎屑、孔石莼碎屑+微绿球藻、角叉菜碎屑、角叉菜碎屑+微绿球藻、裙带菜碎屑、裙带菜碎屑+微绿球藻。栉孔扇贝和虾夷扇贝暂养35 d后,结果显示,投喂孔石莼碎屑+微绿球藻的饵料处理组,两种扇贝性腺发育均优于其它饵料处理组。其中,栉孔扇贝的性腺湿重、干重和灰分重的指数增长量分别为0.034±0.003、0.041±0.003和0.155±0.004,显著高于其它饵料组;虾夷扇贝的性腺湿重、干重和灰分重的指数增长量分别为0.067±0.001、0.013±0.001、0.067±0.004,同样显著高于其它饵料组。此外,投喂孔石莼碎屑+微绿球藻饵料处理组的两种扇贝的亲体增重效果也明显优于其它饵料处理组。研究表明,孔石莼磨碎液与微绿球藻混合,可有效促进栉孔扇贝和虾夷扇贝的性腺发育和体重增长,在扇贝暂养培养阶段可作为替代饵料与单胞藻混合使用。     

生物饵料在非洲斑节对虾溞状幼体培育中的应用

为研究活体生物饵料在非洲斑节对虾(Penaeus mondon)溞状幼体中的应用效果,试验使用牟氏角毛藻(Chaetocevos mueueri)和经牟氏角毛藻强化的褶皱臂尾轮虫(Brachionus plicatilis)替代商品螺旋藻粉(Spirulina platensis)投喂非洲斑节对虾溞状幼体,试验设置3组:对照组(A_0)采用传统的虾片与商品螺旋藻粉在溞状幼体阶段全程投喂;试验组A_1组以牟氏角毛藻替代商品螺旋藻粉投喂;试验组A_2组以牟氏角毛藻替代商品螺旋藻粉投喂,并在Z_2和Z_3期添加投喂经牟氏角毛藻强化的褶皱臂尾轮虫,每组设3个平行。结果表明:3组间溞状幼体成活率差异显著(P0.05),其中A_2组最高(73.9%),A_0组最低(51.4%);在溞状幼体变态时间上,3组间差异显著(P0.05),其中A_2组变态时间最短。试验表明,活体生物饵料替代商品螺旋藻粉有利于非洲斑节对虾溞状幼体培育,效果显著。     

尖紫蛤壳顶幼虫适宜饵料的研究

为了研究尖紫蛤壳顶幼虫适宜饵料种类和投喂浓度,选用5组微藻做为饵料,研究其对尖紫蛤(Soletellina acuta Cai et Zhuang)壳顶幼虫生长和存活的影响。5组微藻分别是A组微绿球藻(Nannochloropsis oculata sp.),B组亚心形扁藻(Platymonas subcordiformi),C组湛江等鞭金藻(Isochrysis zhanjiangensis)+亚心形扁藻,D组绿色巴夫藻(Pavlova viridis)+亚心形扁藻,E组小球藻(Chlorella sp.)+亚心形扁藻。单因素方差分析表明:A组饵料效果为最好;B组和C组的饵料效果次之,E组和D组的饵料效果较差;不同饵料种类下,A组壳顶幼虫有最大生长和存活率;不同饵料浓度下,A组的最适投喂浓度是12 000个/(mL.d),C组的最适投喂浓度是5 000+5 000个/(mL.d)。A组和C组获得了较高的生长速率和成活率,可做为尖紫蛤壳顶幼虫适宜的饵料。     

不同饵料对褶皱臂尾轮虫生长繁殖的影响

为了探讨不同饵料对褶皱臂尾轮虫种群生长繁殖的影响,通过在浓缩小球藻的基础上分别添加蛋黄、鱼肝油、三文鱼油、鱿鱼油和维生素,采用6种不同饵料(或组合)培养轮虫20 d,分析比较各组在轮虫的密度、怀卵量、抱卵率以及水质指标(p H、DO、氨氮)等方面的差异。结果表明,投喂不同的饵料,轮虫密度各组间存在差异,鱼肝油组轮虫密度最大,达到466个/m L,其次是鱿鱼油组和三文鱼油组,单独投喂浓缩小球藻的对照组轮虫密度最小;轮虫怀卵量各组间差异极显著(P0.01),鱼肝油组显著高于其它组(P0.05),最高达到908个/m L,其次为鱿鱼油组,对照组最低;鱼肝油组的抱卵率和日平均增殖率最高,其次是鱿鱼油组;对照组和维生素组的轮虫培养水体水质保持较好,蛋黄组水质最差。研究表明,投喂鱼肝油对轮虫的生长繁殖有显著促进作用,采用浓缩小球藻和鱼肝油混合投喂培养轮虫,可提高轮虫质量和营养价值。     

微绿球藻作为刺参幼体饵料的可行性研究

用微绿球藻新鲜藻液、微绿球藻冷冻浓缩液、微绿球藻干粉+干酵母及干酵母对刺参浮游阶段幼体进行了为期15d的投喂实验。结果表明:以微绿球藻干粉50%+干酵母50%搭配投喂的刺参幼体在生长速率、大耳幼体成活率及樽形幼体变态率方面均表现出显著的优势;单独投喂微绿球藻或干酵母也基本可满足刺参幼体生长发育的营养需求,但生长相对缓慢,成活率及变态率相对较低。另外,单独投喂冷冻浓缩藻液的处理组成活率及变态率都较低。     

几种常见海藻饵料对虾夷扇贝增重效果的影响

通过用微绿球藻、孔石莼、角叉菜、裙带菜四组天然海藻饵料的投喂对比试验对虾夷扇贝增重效果进行评价。26d的对比试验结果显示:投喂孔石莼的虾夷扇贝鲜体重增重率为99.78%±18.51%,均显著高于其余三种饵料组(P0.05),干体重增重率为286.41%±68.13%,,显著高于其余饵料组(P0.05)。对比结果显示,孔石莼饵料组对虾夷扇贝的增重效果显著,在扇贝育苗生产中可作为替用饵料与单胞藻混合使用。     

藻粉与微藻搭配对萼花臂尾轮虫的饵料效果研究

为探讨藻粉作为轮虫培育饵料的可行性,研究了两种藻粉(螺旋藻粉、小球藻粉)分别与微藻蛋白核小球藻、斜生栅藻按一定比例搭配投喂萼花臂尾轮虫的饵料效果。结果表明,用藻粉和微藻适当比例搭配投喂轮虫其效果接近或超过单一用微藻在最适密度下的培养效果;两种微藻中又以蛋白核小球藻与藻粉按4∶1比例搭配对轮虫的饵料效果更好;螺旋藻粉和小球藻粉之间的差异不明显。     

Anguilla huangi Teng, Lin, and Tzeng, 2009, is a junior synonym of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009

Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.     

Effect of Lead on Survival,Osmoregulation, and Histological Changes of the Gills of the White Shrimp,Litopenaeus vannamei,Boone, 1931

The purpose of this study was to evaluate the acute toxicity of lead for different life stages of shrimp, Litopenaeus vannamei, and to determine the effect of its sublethal concentrations on osmoregulatory capacity (OC) as well as the possible histological alteration in the gills of juvenile shrimp. The 24‐, 48‐, and 96‐h LC₅₀ values for lead to L. vannamei increased progressively with increasing life stage, from nauplii < zoeae < mysis < postlarvae < juvenile. After 15‐d exposure to 3.25, 6.50, and 9.75 mg Pb/L, the OC values of exposed shrimp were reduced by 39, 73, and 157%, respectively compared to control animals. Compared to controls, the lead concentrations in gill tissues increased significantly by 127,500, 137,500, and 141,000% in shrimps exposed to 3.25, 6.50, and 9.75 mg Pb/L, respectively. After lead exposure, hemocytic congestion in efferent vessels and multiple hyperplasia were observed in gill filaments, resulting in narrowed hemolymphatic lacuna. The histopathological effects increased with increasing Pb concentration.     

Effects of Mosquitofish,Gambusia affinis,on Channel Catfish,Ictalurus puncatatus,Production Ponds

Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.     

Age,growth, maturity and the overfishing of the iconic sciaenid,Argyrosomus japonicus,in south-eastern,Australia

Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L₅₀ of 68 cm, whereas males matured at 2–3 years of age with a L₅₀ of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.     

Surface disinfection of Pacific threadfin, Polydactylus sexfilis, and amberjack, Seriola rivoliana, eggs

The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L⁻¹ H₂O₂ for 5 min. Exposure to 34 230 mg L⁻¹ H₂O₂ for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L⁻¹ PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>10⁴ cfu egg⁻¹), hydrogen peroxide concentrations of at least 11 340 mg L⁻¹, or PVP‐I concentrations higher than 500 mg L⁻¹ for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L⁻¹) concentrations of H₂O₂ was sufficient to result in high apparent levels of surface sterility (<1 cfu egg⁻¹).     

驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼形态观察

对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。     

Effect of temperature,volume of ova batches,and addition of a diluent,an antibiotic,oxygen and a protein inhibitor on short-term storage capacities of turbot,Psetta maxima,ova

The effect of different parameters on short-term storage capacity of turbot ova was assessed over a 45-h period after ova collection for fertilization rates and over a 9-h period after ova collection for hatching rates. Increasing the volume of ova sampling from 0.5 to 2.5 mL, as well as adding an antibiotic–antimicotic solution or oxygen did not significantly change the storage capacity of ova. Regarding the hatching rates, a higher storage ability was recorded at 8 and 13 °C, compared to 3 °C. The mean composition of the ovarian fluid was determined (n = 57 spawns). Use of a diluent mimicking the ovarian fluid significantly decreased the storage ability as assessed by the fertilization rates but did not modify the hatching rates. Diluting ova in an artificial ovarian fluid deprived of calcium significantly decreased the fertilization and hatching rates during the storage period. Furthermore, addition or not of soybean trypsin inhibitor (Sigma T 9003) to the artificial ovarian fluid deprived of calcium did not significantly change the results. Storage capacity of control batches of ova was low: at 13 °C, without any diluent and when ova were fertilized 3 h after stripping, the hatching rate was lowered to 62.4 ± 29.4 % (mean ± SD) of the initial value.     

Effect of Temperature on Growth,Energy Budget,and Physiological Performance of Green,White, and Purple Color Morphs of Sea Cucumber,Apostichopus japonicus

As an intertidal species, Apostichopus japonicus is subject to diel and seasonal temperature fluctuations. Color variation is a distinct characteristic of A. japonicus, and a new color morph, purple A. japonicus, was recently found on the coast of Rushan, Weihai City. This study was conducted to compare the performance of green, white, and purple color morphs of A. japonicus at different water temperatures to help improving aquaculture technology and management. In this study, green, white, and purple color morphs of juvenile A. japonicus (1.5 ± 0.1 g) were cultured at 10, 14, 18, 22, and 26 C for 60 d, according to the suitable temperature range for sea cucumber growth. Temperature was shown to have a significant effect on growth, energy budget, and physiology of sea cucumbers (P < 0.05). Specific growth rates, feed conversion efficiencies, and the proportion of energy allocated to growth of all three color morphs were optimal at 18 C. Activities of the enzymes related with oxidative stress, immune response, and digestion were determined. Superoxide dismutase (SOD) and trypsin activities generally reached a maximum in all three color morphs at 18 C. The purple color morph of A. japonicus was higher in growth rate, food conversion efficiency, and proportion of energy allocated to growth than green and white color morphs at 18 and 22 C, consistent with its higher trypsin and SOD activity, indicating the mutual effect of growth and physiology. At 18, 22, and 26 C, the green color morph had the highest level of lysozyme activity and purple color morph had the lowest, indicating possible infection by external pathogens of green color morph, which might be caused by high temperature. These results suggested that the optimum temperature for culture of the three color morphs was approximately 18 C, the purple had a better adaption to high temperature, and the green and white color morphs may be more susceptible to thermal stress than the purple color morph.     

Recruitment strategy of swimming crab, Portunus trituberculatus, in Hiuchi-Nada, Japan

The recruitment strategy of swimming crabs, Portunus trituberculatus, was investigated by field observations and numerical experiments in Hiuchi-Nada, Japan. Calculated dispersal patterns of zoeal and megalopal stages in a three-dimensional numerical model reproduce observed patterns accurately. The temporal change of vertical migration patterns between the 1st and 2nd zoeas and the 3rd and 4th zoeas plays an important role in the process of recruitment of P. trituberculatus from spawning ground to nursery ground.     

Effects of Dietary Savory and Myrtle Essential Oils on Growth,Survival, Nutritional Indices,Serum Biochemistry,and Hematology of Farmed Rainbow Trout,Oncorhynchus mykiss,Fry

The effects of diets containing different levels of essential oils from savory Satureja khuzestanica Jamzad and myrtle Myrtus communis L and an immunity complement were investigated on growth, survival, nutritional indices, serum biochemistry, and hematology of farmed rainbow trout, Oncorhynchus mykiss, fry (n = 4500; 5 ± 2 g). The essential oils were dosed as 300 and 500 mg/kg diet. After 60 d, the fish fed 300 mg/kg of the essential oils showed the highest counts of white blood cells (P < 0.05). The same treatment revealed the greatest levels of hematocrit, total protein, and albumin, but glucose and cholesterol values significantly decreased compared with the control (P < 0.05). Feeding fish with 300 mg/kg of the essential oils led to highest records of specific growth rate and survival rate but the lowest feed conversion ratio (FCR), and those fed with immunity complement attained the lowest values of growth parameters. The fry fed with immunity complement and 300 mg/kg of myrtle essential oil achieved the highest and lowest FCR values, respectively. The results indicate that dietary supplementation of 300 mg/kg of the above essential oils exert positive impacts on the growth performance, feeding efficiency, and hematological factors in O. mykiss.