几种饵料对华贵栉孔扇贝浮游幼虫生长和成活率的影响

研究了湛江叉鞭金藻、亚心形扁藻、小球藻、干酵母、湛江叉鞭金藻与干酵母、湛江叉鞭金藻与亚心形扁藻对华贵栉孔扇贝幼虫生长和成活的影响。试验结果表明,投喂金藻和亚心形扁藻混合组生长速度最快,投喂金藻和酵母组次之,单独投喂小球藻和亚心形扁藻时生长速度最差。投喂酵母组成活率最高。     

不同密度、饵料对缢蛏浮游幼体生长及成活率的影响

报导了不同密度、饵料对缢蛏浮游幼体阶段生长速度及成活率的影响.不同密度共设五组,每组设一个平行组,各组密度分别为3、6、9、12、15个/mL;不同饵料共设五组,每组设一个平行组,饵料各组分别为金藻、新月菱形藻、角毛藻、海水小球藻、混合藻.结果表明,在水温23～24℃,经5d培养,不同密度组各组成活率无显著差异.壳高日生长密度为3个/mL组与其他各组之间有显著差异,其他四个密度组之间无显著差异.在不同饵料组壳高日生长中,角毛藻组与其他各组之间差异极显著.新月菱形藻、海水小球藻、混合藻组与金藻组差异极显著.新月菱形藻、海水小球藻、混合藻三组之间无显著差异.日生长最快为角毛藻组24.84 μm/d,最慢为金藻组16.14μm/d.不同饵料成活率金藻组最高为57.77％,最低为海水小球藻组31.1％.     

方斑东风螺人工育苗和工厂化养殖技术二、单细胞饵料在方斑东风螺育苗中的应用

方斑东风螺的人工育苗中常用的单细胞饵料有角毛藻、金藻、扁藻、小球藻、微球藻、塔胞藻等.其中对方斑东风螺幼体发育较好,变态率较高为角毛藻、金藻、扁球藻、微球藻和小球藻等.     

微藻饵料对紫海胆浮游幼体生长及存活影响的研究

文章采用湛江叉鞭金藻(Dicrateria zhanjiangensis)、纤细角毛藻(Chaetoceros gracilis)、绿色巴夫藻(Pavlova viridis)、扁藻(Platymonas subcordiformis)、小球藻(Chlorella vulgaris)及混合藻(金藻和角毛藻1∶1混合)投喂紫海胆(Anthocidaris crassispina),研究了微藻饵料对紫海胆浮游幼体生长发育的影响。结果表明,不同饵料对紫海胆浮游幼体生长发育的效果有差异,金藻是最佳饵料品种,角毛藻次之,其后分别为巴夫藻、小球藻和混合藻,扁藻不适于作为紫海胆浮游幼体的开口饵料。就饵料种类而言,金藻作为紫海胆浮游幼体饵料的成活率可达(23.12±1.8)%,显著高于其他单胞藻类(P<0.05)。就发育速度而言,以角毛藻和金藻混合喂食的海胆浮游幼体整体发育速度最快,幼体平均体长为(885.25±30.49)μm,显著高于其他5种处理(P<0.05);投喂巴夫藻的浮游幼体前期生长较慢,体长为(337.98±24.56)μm,后期较其他单胞藻类生长快,体长可达(580±32.95)μm,适宜作为紫海胆浮游幼体后期饵料。     

单胞藻静置保种技术研究

首次采用静置保种法在高温期和低温期对扁藻、小球藻、金藻８７０１、金藻３０１１及小硅藻进行培养，生长情况良好。用此法保种培养的单胞藻饵料，分别在１４０ｍ＾２育苗水体中育出三倍体太平洋牡蛎苗种３０００多万粒和加拿大海湾扇贝苗种２０００多万粒。设想用此法驯化胞藻耐高温、低温及其它恶劣环境的能力。     

绿裸藻对褶皱臂尾轮虫繁殖的影响

采用首次平均抱卵量和增殖率两项指标评价褶皱臂尾轮虫的繁殖情况,研究了绿裸藻、卵形隐藻和蛋白核小球藻的饵料效果,以及绿裸藻与不同食物混合对褶皱臂尾轮虫繁殖的影响.由于粒度关系,绿裸藻不宜做轮虫的食物,但在保证饵料供应的情况下,绿裸藻对轮虫没有危害.生产上可利用绿裸藻的产氧功能,辅以充足的轮虫食物,以生态调控方式改善轮虫池的水质,有利于土池轮虫培育.     

重盐碱地南美白对虾池塘浮游植物的研究

于2007年6月至9月对利津县陈庄重盐碱地南美白对虾养殖池塘浮游植物的种类组成和生物量进行了研究。共采集水样48个。结果表明,利津重盐碱地养殖池塘浮游植物主要是淡水普生种类,一些是典型的盐水种。浮游植物的优势种为小色球藻、小席藻、针晶兰纤维藻、微小平列藻、铜绿微囊藻、类颤藻鱼腥藻;绿藻门的尖细栅藻、卵形衣藻、湖生卵囊藻和普通小球藻;硅藻门的星肋小环藻、近缘针杆藻;金藻门的卵形单鞭金藻;裸藻门的绿色裸藻;隐藻门的卵形隐藻、啮蚀隐藻和尖尾兰隐藻等。浮游植物的平均密度为6.98×107L-1,变化范围在0.05×107~17.4×107L-1之间;平均重量为51.7 mg/L,变化范围在0.23~207.72mg/L之间。     

不同饵料对真蛸浮游幼体生长和存活的影响

为了满足真蛸浮游幼体阶段的营养需要,研究了几种饵料生物对真蛸浮游幼体的育苗效果。结果表明:轮虫不宜作为真蛸浮游幼体的生物饵料;恒温培养试验得出混合营养强化的丰年虫幼体的育苗效果优于混合营养强化的蒙古裸腹溞,并优于小球藻强化的丰年虫幼体及蒙古裸腹溞;常温试验得出梭子蟹溞状幼体+丰年虫幼体组合的饵料效果最好,而微囊营养强化剂强化的丰年虫幼体的育苗效果好于混合营养组合。综上所述,可认为:梭子蟹溞状幼体+丰年虫幼体组合是真蛸浮游幼体期比较适宜的饵料。     

马氏珠母贝简化式育苗技术

进行了面包酵母、小球藻、扁藻、金藻在马氏珠母贝幼虫不同发育阶段的饵料效果试验,以及不同投饵量在不换水育苗方式中的育苗效果试验。结果表明:在马氏珠母贝人工育苗中D型幼虫期使用面包酵母、壳顶幼虫期使用小球藻,并通过控制投饵量,在不换水的情况下可成功地幼虫培育至变态附着,并进一步培育成商品规格的稚贝,幼虫的附着变态率可达6.5%。     

凡纳滨对虾低盐度养殖池浮游藻类群落研究

在44口凡纳滨对虾低盐度养殖池中共鉴定藻类7门62属113种,蓝藻26种,绿藻54种,硅藻14种,裸藻11种,隐藻3种,甲藻4种,金藻1种。绿藻门种类最多,占藻类种类数的47·8%,其次为蓝藻门占23·0%,硅藻占12·4%,裸藻占9·7%。优势种主要为蓝藻,典型优势种有螺旋藻(Spirulinasp.),假鱼腥藻(Pseudoanabaenasp.),弯形尖头藻(Raphidiopsis curvata),针状蓝纤维藻(Dactylococcopsis acicularis)等,其中螺旋藻的优势度平均达到50%,为主要优势种。常见的绿藻有栅藻(Scenedesmusp.),衣藻(Chlamydomonassp.),小球藻(Chlorella vulgaris)等;常见的硅藻为梅尼小环藻(Cyclotella meneghinian),卵形隐藻(Cryptomonas ovata)、啮蚀隐藻(C.erosa)和绿裸藻(Euglenavirdis)在虾池中比较常见。养殖池中浮游藻类的种类数平均为43±9种,多样性指数平均为2·19±0·56,个体数量平均为1·45±0·87×108个/L;藻类的种类、数量及生物量表现为养殖前期低后期高的特征,而多样性表现相反,藻类的组成直接影响对虾的生长。     

盐度对大银鱼受精卵孵化率的影响

进行了不同盐度对大银鱼受精卵孵化率的影响试验，结果表明，受精卵能够在２０以下盐度孵出仔鱼，但孵化率随盐度的升高而降低，孵出的仔鱼畸形随盐度的升高而升高，胚胎发育速度也相应减慢 。     

Diet composition of sturgeon fry (Acipenser persicus) reared in fertilized earthen ponds

Artificial rearing of fry has been introduced as an alternative to supply fry and juvenile sturgeon in order to restock the depleted sturgeon population in the Caspian Sea. The aim of this study is to assess the feed selection characteristics of sturgeon (Acipenser persicus) fry during the period in which they stay in earthen ponds before being released into the river. Sturgeon fry weighing around 150 mg were introduced into five almost similar‐sized earthen ponds. The ponds were enriched with fertilizer to supply natural food for the fries. A weekly sample of six specimens was collected from each pond during the 5 weeks of the experiment. All collected fish were weighed and then dissected for inspection of the stomach and the intestine content. The overall stomach content measured from 150 fish showed that around 74% of the stomach content was composed of chironomids and the rest was daphnia and cyclops. At the beginning of the study (first 2 weeks), sturgeon fry feed more on daphnia and cyclops; this trend, however, reversed in the last 2 weeks of the study. In conclusion, sturgeon fry feed on three prey groups—chironomids, daphnia and cyclops—during their lifespan in earthen pond. Feeding on chironomids larvae increased with sturgeon fry size.     

Effects of dietary sunflower oil on growth parameters,fatty acid profiles and expression of genes regulating growth and metabolism in the pejerrey (Odontesthes bonariensis) fry

Aquaculture fish diets usually contain an addition of fish oil to improve their nutritional value. The effect of the replacement of dietary fish oil (FO) by sunflower oil (SfO) on growth, fatty acid composition and expression of genes implicated in somatic growth, feed intake and fatty acid metabolism was studied in pejerrey fry. Fry were fed per 45 days with diets containing FO/SfO ratios of 100% FO; 50% FO:50% SfO; 20% FO:80% SfO; and 100% SfO. No differences were detected in growth and in the total per cent of saturated and monounsaturated fatty acids. Gh, ghr‐I and ghr‐II showed a higher mRNA expression in head and trunk of fry fed with 100% SfO diet. Expression of igf‐II was higher in trunk of fry fed with 100% SfO diet compared with 100% FO diet. The Δ6‐desaturase gene expression was upregulated in head and trunk of fry fed with 100% SfO diet. The nucb2/nesfatin‐1 gene expression decreased in the trunk of fry with increasing dietary SfO. We conclude that the replacement of fish oil by sunflower oil in pejerrey fry feed does not affect growth and is a viable strategy to reduce production costs of this fish.     

长江胭脂鱼开口饵料的研究

用不同组合的饵料投喂刚能平游的长江胭脂鱼鱼苗40 d,研究长江胭脂鱼适宜的开口饵料。结果显示,用配合饲料作开口饵料时长江胭脂鱼的开口率、成活率和出池规格都显著低于水蚯蚓组和卤虫组,补充蛋黄后开口率、成活率、出池规格变化不明显,但补充螺旋藻后开口率、成活率、出池规格均显著提高。用配合饲料和卤虫作主体饵料再补充蛋黄和螺旋藻粉也获得了较高的开口率和成活率。建议在水泥池育苗条件下长江胭脂鱼的开口饵料用配合饲料和鲜活饵料作主体饵料并补充少量螺旋藻粉。     

黑鮶控光育苗技术研究

利用体重1～4kg的怀仔黑亲鱼56尾，完全人工控制弱光，长流水、自然水温培育，共产仔272万尾。布池后，根据不同日龄投喂轮虫、卤虫无节幼体、配饵和糠虾，控制光照，调节水质，防病治病，及时疏稀，420m~3水体育出平均全长28.8mm的黑苗77.6万尾，总成活率30％。认为，全人工控制光源蓄养亲鱼，溢水法布池，夜间开灯少量投饵，效果较好。     

Evaluation of Three Feeds for Hatchery Rearing Channel Catfish Fry

Two 7 day feeding trials were conducted with channel catfish swim-up fry to evaluate growth, feed conversion ratio, and body composition of fish fed one of the following feeds: salmon starter, catfish starter, or trout starter. Fish fed the salmon or trout starter feeds gained 50–75% more weight, converted feed more efficiently, and had higher body fat stores than fish fed the catfish starter feed. This may be related to the higher protein and energy content of these two feeds. It may be advantageous to feed salmonid starter feeds to hatchery reared catfish fry; however, it is not known whether or not the improved performance observed in the hatchery continues once the fish are stocked into nursery and grow out ponds.     

美洲鲥苗种绿色生产试验

采用由美国的野生美洲鲥亲本人工繁育而来的子一代亲本进行苗种绿色生产试验,孵化育苗用水经过严格的消毒、过滤等处理,尾水通过水循环系统净化后排放,开口饵料以自行扩培的方式生产,并在种鱼养殖和苗种培育过程中使用经绿色生产资料认证的饲料。试验结果显示:养殖和育苗用水符合NY/T 391—2013《绿色食品产地环境质量》,排放水符合SC/T 9101—2007《淡水池塘养殖水排放要求》,孵化育苗过程顺利,获得美洲鲥苗种4.67万尾,苗种符合NY/T 842—2012《绿色食品鱼》的要求。     

Controlled hatchery production of Clarias gariepinus (Burchell 1822): growth and survival of fry at high stocking density

Abstract. The growth and survival of Clarias gariepinus (Burchell) fry was investigated at high stocking density. Significant increases in mean fry weight, and concomitant significant decreases in specific growth rate, were recorded over successive 5-day periods. Fry growth was negatively density dependent. Fry survival was in excess of 90% in all treatments. Increasing stocking density between 50 and 150 fish/l altered the pattern of mortality; non-cannibalistic deaths decreased significantly with increasing stocking density though cannibalism did not significantly increase. Periods of weaning fish onto larger feed particles were associated with temporarily increased rates of cannibalism.     

Evaluation of 100% Fish Meal Substitution with Chicken Concentrate,Protein Poultry By‐Product Blend,and Chicken and Egg Concentrate on Growth and Disease Resistance of Juvenile Rainbow Trout,Oncorhynchus mykiss

The ability of poultry products to replace fish meal in diets for rainbow trout, Oncorhynchus mykiss, depends on their nutrient composition, cost, and consistency. The aim of this study was to assess the ability of three commercially available poultry products (chicken concentrate, CC, poultry by‐product blend, PBB; or chicken and egg concentrate, CE) to maintain growth and disease resistance when substituted for fish meal in a rainbow trout starter diet. A control diet was formulated to contain 48% crude protein and 18% crude lipid; 100% of the fish meal in test diets was replaced with CC, PBB, or CE. At stocking, fry were counted into groups (50 fish/tank) with six replicate tanks for each diet and fed their respective diets four times daily for 8 wk. All the poultry‐based diets supported growth (over 1600% increase over initial weight), nutrient retention, and feed conversion ratios of rainbow trout fry equal to or greater than those observed for fry fed with the fish meal‐based diet. No effect of diet on survival was observed following subcutaneous injection challenge with Flavobacterium psychrophilum. These data suggest that the examined products can be used in place of fish meal for rainbow trout fry without lowering growth and disease resistance.     

Survival and Growth of Walleye Stizostedion vitreum Fry as Affected by Water Recirculation, Feed Transition Age, and Stocking Density

Abstract.— The effects of recirculation aquaculture on walleye Stizostedion vitreuin fry culture was evaluated from hatch (day 0) to day 65 and compared to traditional flow-through aquaculture used at New York State's Fish Culture Station, Oneida, New York, USA. A comparison of survival rates of walleye fry through a feed transition period was also conducted with the variable being the age (d) at which dry feed was first introduced to fingerlings; this trial was conducted using recirculation aquaculture systems only. Comparisons were made of growth rates and survival rates broken down into two life stages: stage one was from day 0 to day 45 and stage two from day 45 to day 65. All systems were taken off live feed completely on day 45 resulting in a feed transition period between days 45 and 65. Fish in the flow-through system had the highest cumulative growth rates through day 70 (P < 0.05) while fish in the recirculating system grew faster through day 53 (P < 0.10). The recirculating system showed significantly higher survival rates during the feed transition period (day 45–65) than fish in the conventional flow-through system (P < 0.05). This is important because the transition period is the most stressful period in training fingerlings onto dry feed from a live diet. It was found that fish started on a dry diet on day I or day 14 in addition to the live diet had a significantly higher survival rate through the feed transition period than fish started on dry feed on day 30 (P < 0.1). The age at which dry feed was introduced had no significant impact on growth rates. There was a significant positive correlation (P < 0.05) between survival rates and the initial stocking density over a range of densities from 3,500 to 7,000 fish/m³.