四种常用药物对黄鳝苗种的敏感性试验

采用常温静水实验法，进行孔雀石绿、高锰酸钾、敌百虫、强氯精对黄鳝（Monopterus albus)(体长11－15cm,平均体重3．6克／尾）的急性毒性试验，结果表明：4种药物对黄鳝苗种的96h半致死浓度（96hLc50)分别为3．654、5．775、7．407、18．520mg/L；安全浓度（So)，分别为0．3654、0．5773、0．7407、1．852mg/L。黄鳝苗种对高锰酸钾最敏感，敌百虫次之；最不敏感的为强氯精，其次为孔雀石绿。     

4种药物对中国花鲈苗种的急性毒性试验

研究了4种药物对中国花鲈苗种的急性毒性试验,试验结果为：硫酸铜半致死浓度分别为4．58mg／L（24h）、2．93mg／L（48h）、1．81mg／L（72h）、0．78mg／L（96h）,安全浓度为0．36mg／L。杀虫威半致死浓度分别为35．11mg／L（24h）、15．81mg／L（48h）、11．20mg／L（72h）、9．36mg／L（96h）,安全浓度为0．96mg／L。福尔马林半致死浓度分别为225．58mg／L（24h）、176．97mg／L（48h）、150．31mg／L（72h）、141．45mg／L（96h）,安全浓度为32．77mg／L。聚维酮碘半致死浓度分别为227．00mg／L（24h）、145．50mg／L（48h）、113．11mg／L（72h）、101．84mg／L（96h）,安全浓度为17．93mg／L。4种药物对中国花鲈苗种的毒性大小依次为：硫酸铜〉杀虫威〉聚维酮碘〉福尔马林。     

鲢鱼苗对一些常用药物的敏感性试验

摘要通过试验确定了3种药物对鳃鱼苗的最低致死浓度范围,半致死浓度和安全浓度。试验中其它8种药物对鳃鱼苗不敏感。鱼苗对3种药物的敏感性大小依次为富渔虫灭〉立效清〉车轮速灭。     

黄鳝苗种对四种常用药物的敏感性试验

采用常温静水实验法,进行孔雀石绿、高锰酸钾、敌百虫、强氯精对黄鳝(Monopterusalbus)(体长11-15cm,平均体重3.6g/尾)的急性毒性试验,结果表明:4种药物对黄鳝苗种的96h半致死浓度(96hLc50)分别为3.654、5.775、7.407、18.520mg/L;安全浓度(Sc)分别为0.3654、0.5773、0.7407、1.852mg/L.黄鳝苗种对高锰酸最敏感,敌百虫次之;最不敏感的为强氯精,其次为孔雀石绿.     

大鳍鳠对8种常用水产药物的敏感性试验

体长7~8cm的大鳍鱼萑又对8种常用水产药物的敏感性强度为:硫酸铜>高锰酸钾>甲醛>强氯精>漂白粉>敌百虫>食盐>亚甲基蓝。安全质量浓度除亚甲基蓝外依次为0.085、0.233、5.21、0.3、0.74、0.497、1045mg/L。硫酸铜不宜作为防治药物,高锰酸钾不宜作为浸洗药物。     

银鲈的两种放养密度对比试验

银鲈的两种放养密度对比试验ＳｔｕａｒｔＪ．ＲｏｗｌａｎｄＧｅｏｆｆＬ．ＡｌｌａｎＭａｔｔｅｗＨｏｌｌｉｓＴｒｅｖｏｒＰｏｎｔｉｆｅｘ淡水银鲈（Ｂｉｄｙａｎｕｓｂｉｄｙａｎｕｓ）是澳大利亚特有的养殖品种，它具有生长快、杂食性，可用人工配合饵料饲养等优点...     

丁(鱼岁)对几种药物的敏感性研究

用硫酸铜、高锰酸钾、强氯精、敌百虫对丁（鱼岁）进行药物毒性敏感性试验。结果表明：丁（鱼岁）对硫酸铜、高锰酸钾、强氯精、敌百虫的敏感顺序为：硫酸铜＞高锰酸钾＞强氯精＞敌百虫，安全浓度分别是：0．32mg／L、0．64mg／L、1．05rng／L，丁（鱼岁）对敌百虫敏感性不强。     

赤眼鳟对常用水产药物的敏感性试验

赤眼鳟对试验药物的敏感性大小依次为:硫酸铜>天使蓝>菌敌>高锰酸钾>百虫杀>敌百虫>甲醛>土霉素>氯化钠。它们的安全浓度分别为:0.064、0.186、0.63、1.66、3.88、8.53、23.3、44.4、1919m g/L。在赤眼鳟鱼病防治中,建议禁用硫酸铜、天使蓝;慎用高锰酸钾和菌敌;氯化钠一般作为浸浴消毒使用,而百虫杀、敌百虫、甲醛、土霉素、聚维酮碘均可安全使用。     

小口脂鲤对几种常用药物的敏感性试验

在水温 2 6～ 30℃下 ,敌百虫等十种常用药物对小口脂鲤夏花鱼种的安全浓度分别为 :敌百虫 0 .0 4 2 mg/ L、甲醛 18.2 0 mg/ L、硫酸铜合剂 0 .98mg/ L、孔雀石绿 0 .0 35mg/ L、高锰酸钾0 .93mg/ L、鱼虫克星 0 .0 37mg/ L、强氯精 0 .13mg/ L。呋喃唑酮、土霉素、亚甲基蓝的试验最高浓度分别为 6 4 mg/ L、6 4 mg/ L、8mg/ L,在此浓度下 ,2 4 0小时内小口脂鲤夏花鱼种全部存活。以安全浓度作为衡量标准 ,小口脂鲤夏花鱼种对上述药物的敏感性依次为 :孔雀石绿 >鱼虫克星 >敌百虫 >强氯精 >高锰酸钾 >硫酸铜合剂 >甲醛。其中孔雀石绿、敌百虫的安全浓度仅为常用浓度的 10 %～ 30 % ,故不宜使用。鱼虫克星、强氯精的安全浓度较低 ,在疾病防治中可谨慎使用。     

丁(Tinca tinca)对五种常用药物的敏感性试验

通过预备性试验,初步确定丁瞯在克虫王、硫酸铜、固体二氧化氯,聚维酮碘、福尔马林中48h内死亡0～100%时的浓度范围,然后按寇氏法(Karber)设计正式实验,求得5种药物对丁瞯鱼种的最低致死剂量浓度范围、中间忍受限和安全浓度。结果表明,丁瞯对5种药物的敏感性由强到弱依次为克虫王,硫酸铜和硫酸亚铁合剂,固体二氧化氯,聚维酮碘,福尔马林。     

Domestication of Silver Perch,Bidyanus bidyanus,Broodfish

Abstract

Most breeding programs for the Australian native freshwater silver perch, Bidyanus bidyanus, are based on fish originally captured from natural populations. However, over the last 20 years, there has been a dramatic decline in the distribution and abundance of silver perch in the wild and the species now has the conservation status of “vulnerable.” Unless broodfish can be domesticated a serious shortage is imminent. The aims of this study were to determine the age and size at sexual maturity and the reproductive performance of silver perch reared in captivity. Fingerlings (mean weight, 4.0 g) from a hatchery were stocked into an aerated 0.32-ha earthen pond at a density of 22,000 fish/ ha for 12 months, harvested, and restocked at 10,000 fish/ha for a further 2 years. The fish were fed a formulated diet containing 35% crude protein. No fish were mature at 1 year of age; at 2 years, most males (93%; total length, 304.0 mm, weight 412.7 g), but no females were mature; and at 3 years, most females (97%; 316.4 mm, 549.6 g) were mature. Three-year-old fish injected with 200 IU/kg human chorionic gonado-trophin spawned viable gametes. High fecundity (mean 139,286 eggs/ kg), fertilization rates (84.5%) and hatch rates (76.8%) demonstrate that broodfish can be domesticated and the life cycle of silver perch can be closed. The use of domesticated broodfish will eliminate reliance on wild populations and provide a basis for future hatchery production and selective breeding programs.     

Effects of genetic strain and holding facility on the characteristics of alkaline phosphatase and brush border enzymes in silver perch (Bidyanus bidyanus)

The activity of the enzymes located in the digestive tract (pyloric caeca and intestine) in two strains and F₁ crosses of the Australian freshwater fish silver perch [Murray River (M) and Cataract Dam (C)] was evaluated. The effect of the fish holding system (cages or ponds) on the activity of alkaline phosphatase (AP) and the brush border enzymes: maltase, leucine amino peptidase (LAP) and γ‐glutamyl transferase (γ‐GT) was examined. The enzymatic activity was tested in three intestinal sections: the pyloric caeca, upper and lower intestine. All the tested enzyme activities were influenced by an interaction between the intestinal section and the strain or cross of silver perch. For fish maintained in ponds, there were two distinct enzymatic activity patterns, one for the pure strains (C × C and M × M) and one for the crosses (C × M and M × C). Significantly higher (P<0.05) enzymatic activities of the crosses compared with the pure strains were particularly noticeable in the pyloric caeca. In fish held in cages, there was a significantly higher (P<0.05) enzymatic activity in the pyloric caeca of the C × C strain. The total enzymatic activities in the fish reared in the ponds were significantly higher (P<0.05) than those in the fish held in cages. The results of the present investigation confirm that the different genetic background of the silver perch in the Murray River and in the Cataract Dam influences the activity of the brush border digestive enzymes. This activity also varies between maintenance systems.     

Evaluation of silver perch (Bidyanus bidyanus, Mitchell) nutritional requirements during grow-out with high and low protein diets at two feeding levels

Silver perch (Bidyanus bidyanus, Mitchell) of 65 g average weight were reared at high density under controlled conditions on diets containing 24.8% and 40.6% protein. Diets were fed at 2% or 4% of the fish biomass day^?1. Both protein concentrations and feeding level of the diet influenced growth and proximate composition of the fish at the end of the 50‐day growth trial. Energy requirement for maintenance for these fish was found to be 77 cal BW^?0.8 and for each unit of energy retained 3.78 cal BW^?0.8 needed to be supplied, and for each gram of protein retained per metabolic body weight 5.04 g were required. The results indicate that it is possible to obtain the same weight increment when feeding a 24.8% protein diet at a level of 4% body weight day^?1 as compared with only 2% body weight day^?1 of a 40.6% protein diet. This study indicates that the nutritional requirements for early grow‐out are similar to those found in a previous study with juvenile silver perch and adds information concerning the required relationships between dietary amino acids. The results provide information required for further refinement of nutrition for this species.     

Effects of steam pelleting or extrusion on digestibility and performance of silver perch Bidyanus bidyanus

The effects of different processing techniques on apparent digestibility coefficients (ADCs) and performance of silver perch Bidyanus bidyanus were evaluated. Results of a factorial digestibility trial, in which three diets (SP35, 95LC1 and 95LC2) and three processing methods (cold pelleted, steam pelleted and extruded) were evaluated, indicated that extrusion, but not steam conditioning, significantly improved ADCs of dry matter (DM) and energy. ADCs of DM and energy of cold‐pelleted diets were statistically similar to steam‐pelleted diets, and ADCs of nitrogen were unaffected by processing method. No interaction was found between diet type and processing method for DM, energy or nitrogen ADCs. A performance trial indicated that feed intake, weight gain and specific growth rate of fish fed steam‐pelleted diets was greater than those of fish fed extruded diets. Feed conversion and digestible protein efficiency was better in fish fed extruded diets. The results indicated that extruded diets were better utilized than steam‐pelleted diets; however, voluntary intake of extruded diets may have been limited. Fish fed cold‐pelleted SP35 exhibited inferior performance compared with fish fed steam‐pelleted or extruded SP35. Reduced performance of fish fed this diet may relate to poor utilization of digestible protein or reduced palatability. Diets for silver perch with similar formulations to SP35 and 95LC2 should be steam pelleted.     

银鲈胚胎和仔、稚鱼发育观察

实验对银鲈受精卵的胚胎及仔、稚鱼发育进行连续跟踪观察,结果表明:银鲈受精卵具有在淡水鱼类中比较少见的油球,水温25.4～27.8℃条件下,24小时胚胎破膜而出.出膜仔鱼3日龄开始平游,消化道形成,已能开口摄食;35日龄全长2.3～3.0cm,全身已布满鳞片,形态已具备成鱼特征.     

Heterosis in fingerlings from a diallel cross between two wild strains of silver perch (Bidyanus bidyanus)

Cross-breeding was investigated as a strategy to improve performance of the Australian native freshwater fish, silver perch ( Bidyanus bidyanus Mitchell) through the exploitation of heterosis during the fingerling phase of production. Growth, and mid and best parent heterosis of two wild strains, Cataract Dam (C_♂× C_♀) and Murray River (M_♂× M_♀) and their reciprocal crosses (C_♂× M_♀ and M_♂× C_♀) were evaluated in cages and ponds through summer, and in tanks in a re-circulating aquaculture system during winter. The M × C cross grew significantly faster than the reciprocal cross and pure strains in cages and tanks, had the lowest coefficients of variation of weight and length and was 20.9% and 16.0% heavier than mid-parent and best-parent average, respectively, when grown in ponds. Differences in growth between the reciprocal crosses were also evident, with C × M expressing significantly less heterosis in cages and tanks. Faster growth of M × C was attributed to greater appetite; however, at sizes approaching 250 g this feeding vigour diminished. The results of this study suggest that use of the M × C cross has the potential to reduce the length of the culture period and lower costs of silver perch production.     

Carbohydrate utilization by juvenile silver perch, Bidyanus bidyanus (Mitchell). I. Uptake and clearance of monosaccharides following intraperitoneal injection

Abstract Intraperitoneal carbohydrate tolerance tests were done to assess the ability of silver perch, Bidyanus bidyanus, to utilize the predominant monosaccharides in plant ingredients currently being used in the formulation of aquaculture feeds for this species. Preliminary experiments carried out to assess baseline plasma glucose concentrations indicated that blood glucose levels were elevated within 2 min of handling and silver perch required a period of 48 h without feeding before plasma glucose levels remained constant. In the first carbohydrate test, either glucose, galactose or xylose were administered by injection into the intraperitoneal cavity at a dose rate of 1 g carbohydrate kg^?1 body weight (BW). In the second carbohydrate test, glucose was administered at a dose rate of either 2 or 4 g glucose kg BW^?1. Following injection, uptake and clearance rate of the carbohydrates from the blood stream was monitored over a 24‐h period. Silver perch were significantly more efficient at the uptake and clearance of glucose from the blood stream than xylose or galactose. Maximum plasma glucose concentrations (22.2 mmol L ^?1) were recorded at 1 h following injection and basal levels (3.44 mm ) were attained between 6 and 12 h following injection. For both galactose and xylose, maximum concentrations were recorded at 1 and 3 h, respectively, and concentrations of both monosaccharides remained significantly elevated 24 h after the administration. Plasma glucose concentrations of silver perch administered with either 2 or 4 g glucose kg BW^?1 were significantly elevated and peaked at similar levels (30.2 mmol L ^?1 and 30.7 mmol L ^?1 respectively) 3 h after injection. Basal plasma glucose concentrations were attained in silver perch injected with 2 g glucose kg BW^?1 at 24 h following administration. Plasma glucose concentrations remained significantly elevated in fish injected with 4 g glucose kg BW^?1 after 24 h. These findings indicate that silver perch are more efficient at utilizing glucose than either xylose or galactose, and that there are also differing maximum threshold for the inclusion of ingredients rich in glucose, galactose and xylose into the diets of silver perch.     

Use of temperature to manipulate circulus patterns on scales of silver perch, Bidyanus bidyanus (Mitchell), for the purpose of stock discrimination

Abstract  Controlled temperature variation was used to induce marks on scales of silver perch, Bidyanus bidyanus (Mitchell), for stock identification. Genetically similar fish were held in tanks at three temperatures for a period of 4 weeks. Circulus spacing information was acquired using automated video digitizing equipment. Discriminant function analysis was used to classify fish into their respective rearing temperatures. Fish held at 30°C were classified with high accuracy (94–96%). Classification inaccuracies increased in fish held at the lower temperatures. Fish growth at each temperature was examined and classification accuracies were a reflection of growth differences. The use of temperature variables to induce marks on scales offers scope for batch-marking pre-stocked fish.     

Carbohydrate utilization by juvenile silver perch, Bidyanus bidyanus (Mitchell). III. The protein-sparing effect of wheat starch-based carbohydrates

The ability of juvenile silver perch (Bidyanus bidyanus) to utilize dietary raw wheat meal, raw wheat starch, gelatinized wheat starch and dextrin as energy sources to spare protein for growth was quantified. Energy utilization and protein sparing were assessed by comparing the weight gain, energy retention efficiency, protein retention and body composition of silver perch that had been fed a series of diets in which the basal diet (low carbohydrate) was systematically replaced with graded levels of each carbohydrate ingredient or an inert diluent, diatomaceous earth. The protein content decreased as the carbohydrate content increased, giving four different protein to energy ratios for each of the four carbohydrate sources (except for the 60% inclusion level, at which only three carbohydrate sources were tested). Silver perch were efficient at utilizing carbohydrate for energy to spare protein. Silver perch fed diets containing up to 30% wheat meal, raw wheat starch, gelatinized wheat starch or dextrin exhibited similar growth, protein retention and energy retention efficiency to the fish fed the basal diet. Weight gain of silver perch fed diets containing wheat meal or carbohydrates at 45% inclusion content had significantly reduced weight gain when compared with fish fed the basal diet. However, protein retention and energy retention efficiency were similar or better. Whole‐body protein levels of silver perch remained constant regardless of carbohydrate sources, and there was no evidence of increasing whole‐body lipid concentrations for fish fed diets with up to 60% dietary carbohydrate. Silver perch were more efficient at utilizing processed starch (either gelatinized starch or dextrin) than wheat meal or raw wheat starch.     

Use of formalin and copper to control ichthyophthiriosis in the Australian freshwater fish silver perch (Bidyanus bidyanus Mitchell)

Infestations of the protozoan parasite, Ichthyophthirius multifiliis, cause the serious disease ichthyophthiriosis in freshwater fish throughout the world. Formalin is a recommended treatment for ichthyophthiriosis in the Australian fish silver perch (Bidyanus bidyanus Mitchell), but the disease is difficult to control in ponds, particularly at low water temperatures. Experiments were carried out to develop an improved treatment regime for formalin and to evaluate copper as a therapeutant. Silver perch fingerlings infested with I. multifiliis were stocked into 55 L aquaria at temperatures of 14.8–17.6 °C and alkalinities of 70–110 mg L^?1. Formalin (34–38% formaldehyde) or copper (24.5% copper sulphate) were added to the aquaria and then monitored and readjusted to nominal concentrations daily. A concentration of 30 mg L^?1 formalin controlled ichthyophthiriosis, but fish treated with 20 mg L^?1 remained infested with theronts and trophonts on day 17; survival at both concentrations was 100%. A concentration of 10 mg L^?1 formalin did not control ichthyophthiriosis and all fish were dead from the infestation by day 17. Fish treated with 0.1 or 0.2 mg L^?1 copper were free of theronts and trophonts by days 17 and 14, respectively, and survival was 100%. Survival at 0.05 mg L^?1 copper was 100%, but fish remained infested. At 0.25 mg L^?1 copper, survival was 82.5% and there were no theronts or trophonts on gill and skin tissues of fingerlings by day 14. There was total mortality of fish treated with 0.5 or 1.0 mg L^?1 copper suggesting these concentrations are toxic to silver perch. All fish in infested‐control treatments died. In earthen ponds containing silver perch, 0.2 mg L^?1 copper was depleted to below 0.1 mg L^?1 within 24 h, and concentrations of 25–38 mg L^?1 formalin were depleted to below 15 mg L^?1 within 48 h. Treatment regimes involving daily applications of formalin or copper controlled ichthyophthiriosis in silver perch in earthen ponds at costs of $US466.37 and $US65.58 hectare^?1 day^?1 respectively. This study has developed a new formalin‐treatment regime for the control of ichthyophthiriosis, and demonstrated that copper sulphate is a potential therapeutant for this serious disease of silver perch.