共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
澳洲鳗仔鳗增长率及成活率的研究 总被引:2,自引:1,他引:1
以澳洲鳗仔鳗为研究对象,测定它们在饲养初始阶段的增长率和成活率。得出其个体平均特定增长率为1.88%/d~2.31%/d,总成活率93.79%。与有关欧洲鳗的报道相比,其特定增长率、成活率明显高于欧洲鳗。由此证明澳洲鳗与日本鳗、欧洲鳗一样,能适应人工饲养环境和接受配合饲料。本文亦对部分澳洲鳗仔鳗因拒食导致死亡的现象作了描述和分析。 相似文献
5.
长体鳜、黑鳍鳈及塘鳢的染色体组型研究 总被引:2,自引:0,他引:2
本文报道了长体鳜(Coreosiniperca roulei)、黑鳍鳈(Sarcocheilichthys nigri-pinnis nigripinnis)及塘鳢(Odontobutis obscurus)等三种鱼的染色体组型。长体鳜2N=46,其中亚中部着丝点染色体1对,亚端部着丝点染色体4对,端部着丝点染色体18对。黑鳍鳈2N=50,其中中部着丝点染色体11对,亚中部着丝点染色体10对,端部着丝点染色体4对,塘鳢2=44,22对染色体全部为端部着丝点染色体。长体鳜的染色体组型图为首次报道。 相似文献
6.
7.
通过测定不同水温下的采食率,间接确定澳洲鳗(Anguilla austrulis)的适宜养殖温度,并观察高温下的死亡状况和极限生存温度,发现澳洲鳗的适宜养殖温度接近于24℃,略高于欧洲鳗,略低于日本鳗,在18℃和35℃水温下,澳洲鳗仍有较强的采食率,致死上限温度为37℃,鱼苗比隔年老鳗有更好的耐热能力。 相似文献
8.
9.
10.
黄颡染色体组型的初步分析 总被引:1,自引:0,他引:1
采用体内注射PHA和秋水仙素,肾细胞短期培养,常规空气干燥法制备黄颡鱼的染色体玻片,对100个中期分裂相记数统计,确定黄颡的2倍染色体数为2n=52。由测得的核型参数和按Levan等提出的染色体划分标准得出:有14对中部着丝点染色体(m);5对亚中部着丝点染色体(sm);4对亚端部着丝点染色体(st);3对端部着丝点染色体(t)。其染色体总臂数(NF)为90,黄颡核型公式为2n=28m 10sm 8st 6t。 相似文献
11.
To handle large river eels during procedures such as measuring and tagging for field and aquaculture studies, they must be anaesthetized. During our initial biological studies of Anguilla reinhardtii (Steindachner) it was found that the anaesthetic benzocaine was relatively expensive and elicited a variable response, even when used at relatively high concentrations. Human health risks are also a concern when using benzocaine, as some of the eels may later be sold for human consumption. Therefore, experiments were done to evaluate the use of clove oil (a safe, naturally occurring product) for anaesthesia of this species at a range of temperatures (17 and 25 °C) and salinities (0–32 g L?1). It was found that clove oil provided a suitable anaesthetic response through this wide range of temperatures and salinities. Response times were found to be relatively variable for both benzocaine and clove oil. This variability may be related to stress, environmental factors, or the condition of the fish. Clove oil is recommended for anaesthesia of anguillid eels because it is effective, relatively inexpensive, and poses little risk to human health. 相似文献
12.
13.
The Australian shortfin eel, Anguilla australis is a potential candidate for intensive aquaculture. The present study was undertaken to evaluate the growth of elvers (5.4 g ± 0.1 initial weight) fed with diets of varying protein and lipid content, and to assess the potential of using soya‐bean meal as a dietary ingredient. A 10 week experiment was conducted at 24 (±1.0) °C by rearing fish, in 60 L conical fibre glass tanks using a closed recirculation system. Diets having protein concentrations of 40 or 50% (by dry weight) were tested at three lipid levels (15, 20, 25%); diets being designated P40L15, P40L20, P40L25, P50L15, etc. All these diets contained 5% soya‐bean meal. In addition P50L20 diets were formulated to contain 10 and 20% soya‐bean meal in the diet (Diets S1 & S2). Shortfin eel grew best on the P50L15 diet, with an average specific growth rate of 2.26%. Food conservation ratio (FCR) and Protein efficiency ratio (PER) ranged from 1.21 (P50L15) to 2.12 (P40L25), and 0.92 (P50L25) to 1.65 (P50L15), respectively. Based on all criteria the best growth performance of shortfin eel was on the P50L15 diet, followed by P40L20 and P40L15. At both protein levels fish reared on diets with 25% lipid performed poorly. The performance of shortfin eel was not affected by the amount of soya‐bean meal in the diet, up to a maximum of 20% dietary inclusion. No significant differences in muscle protein were evident in shortfin eel reared on different dietary treatments, nor was the lipid content of muscle related to dietary lipid level. 相似文献
14.
William D. Riley Alan M. Walker Barry Bendall Mark J. Ives 《Ecology of Freshwater Fish》2011,20(4):628-635
Abstract – The movements of wild European eels (Anguilla anguilla L.) were monitored continuously over a 2‐year period in a tributary of the River Itchen, Hampshire, UK, using a passive integrated transponder (PIT) antenna system. The time of these movements was then related to a number of monitored and calculated environmental parameters. No eel movements were recorded in the winter months when mean stream temperature was below 10 °C. The numbers of movements peaked in May, when mean water temperatures and day length were increasing. The movement of eels was significantly (P < 0.001, R2 = 0.45, N = 72) correlated with the time of sunset, with the majority (72%) recorded during the hours of darkness. The results of this investigation have implications for the design/timing of surveys of yellow eel populations and their habitat associations and suggest that successfully determining the microhabitat preferences of active resident eels will require remote monitoring throughout the 24‐h period. 相似文献
15.
16.
17.
日本鳗鲡腐皮病病原菌的分离及鉴定 总被引:5,自引:3,他引:5
从患腐皮病的日本鳗鲡(Anguilla japonica)体表溃烂处分离到1株病原菌(322A),对其进行了人工感染实验和生理生化分析,测定了该菌株的16S rRNA基因序列和促旋酶(gyrase)B亚单位gyrB基因序列,并分别构建系统发育树。结果显示:感染实验证实菌株322A具有致病性;生理生化分析鉴定该菌株属于气单胞菌属(Aero-monassp.);16S rRNA基因分析显示,该菌株与气单胞菌属细菌的同源性均在99%~100%,构建的系统树显示,菌株322A与嗜水气单胞菌(A.hydrophila(FJ462702))亲缘关系最近;gyrB基因分析表明,该菌株与A.hydrophila种内序列的相似性为96%~98%,种间序列的相似性为94%~95%,构建的系统树结果显示,该菌株与A.hydrophila(FJ608553、FJ608552、AF208259)聚为一个分支。综合上述实验结果,菌株322A可鉴定为嗜水气单胞菌(A.hydrophila)。 相似文献
18.
In this experiment, 23% of fish meal protein was replaced with protein from Australian soybean meal (SBM), lupin meal (LM), corn gluten meal (CGM) and meat meal (MM) in nutritionally balanced experimental diets. Growth and growth efficiencies of juvenile Australian short‐finned eel Anguilla australis australis (Richardson) elvers (2.23±0.4‐g average wet weight) were compared. Elvers were fed twice a day to a total of 5% body weight per day for 63 days. Total weight gain (g), specific growth rate (% day?1), protein efficiency ratio (%) and productive protein value (%) were significantly higher (P<0.05) for elvers fed the MM diet than for those fed the LM diet. There were no differences in diurnal ammonia‐nitrogen excretion rates. However, diurnal urea‐nitrogen excretion rates were significantly (P<0.05) affected by diet and rates were two to three times higher for all diets, except CGM, 4 h following the afternoon feed. Diet significantly affected apparent digestibility (AD); ADs of protein for SBM and LM were significantly (P<0.001) higher than for control diet, CGM and MM; AD of energy for LM was significantly (P<0.05) lower than for all the other diets. Fish meal protein was replaced by CGM, SBM and MM without compromising growth rates of the Australian short‐finned eel. However, whole lupin seed meal (LM) depressed growth and growth efficiencies most likely because of the high indigestible carbohydrate content. 相似文献
19.
中草药添加剂对日本鳗鲡生长和非特异性免疫效应的研究 总被引:2,自引:2,他引:2
在基础饲料中分别添加0.5 g/kg、1.0 g/kg和1.5 g/kg的自制中草药免疫添加剂,配制成3种试验饲料,以基础饲料为对照组饲料,每处理设3个平行样,对体重为30~40 g的日本鳗鲡(Anguilla japonica)进行为期60 d的饲养试验,每20 d取样一次,以相对增重率、成活率和血清中的溶菌酶(LZM)、一氧化氮合酶(NOS)、碱性磷酸酶(AKP)和超氧化物歧化酶(SOD)活性为指标,探讨了中草药免疫添加剂对日本鳗鲡生长和非特异性免疫效应的影响。结果显示:饲料中添加中草药免疫添加剂可以显著提高日本鳗鲡的增重率,降低饲料系数(P<0.05)。试验组日本鳗鲡血清中的LZM、NOS、AKP和SOD等活性均高于对照组。因此,中草药免疫添加剂具有显著促生长和增强机体免疫能力的作用,建议在实际生产中的添加量为1.0 g/kg较为合适。 相似文献