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1.
为揭示斜带石斑鱼对碳水化合物利用的特点,研究了3个碳水化合物水平及饥饿处理对其生长、血浆生化指标及肝/肌糖原的影响。实验选取300尾初重为(35±0.28)g的幼鱼,设置持续投喂高(35%,CH)、中(21%,CM)、低(7%,CL)3个碳水化合物水平组,以及持续投喂组(CM)、饥饿再投喂组(R,饥饿4周+投喂4周,投喂CM组饲料)、饥饿组(S)3个投喂模式组。饲养8周后饥饿24 h,以30 mg/100 g体质量腹腔注射葡萄糖研究其代谢反应。结果显示,增重率和特定生长率随饲料碳水化合物水平的增加而升高,但无显著差异,饲料系数以CL组最高。不同碳水化合物水平下,各组注射葡萄糖后1~3 h血糖水平达峰值,但CM组在6 h内迅速回到注射前水平;各组血浆胰岛素水平均先降后升,但CL组在3 h后急剧下降;各组肝糖原、血浆甘油三酯含量在注射后1 h内均显著上升。饥饿处理下,持续投喂组(CM)血糖水平在6 h时迅速恢复至注射前水平;CM组和R组血浆胰岛素在1 h内显著下降,但S组持续上升;CM组血浆甘油三酯含量在0~6 h内显著高于其他两组。研究表明,饲喂中等水平碳水化合物(21%)比较符合斜带石斑鱼糖耐受能力,而饥饿处理下则以持续投喂组糖耐受能力最强。  相似文献   

2.
本实验以我国重要的海水养殖鱼类大黄鱼[初始体质量(13.57±0.33)g]为研究对象,在浮式网箱中进行为期8周的摄食生长实验,探讨饲料脂肪水平和投喂频率对大黄鱼生长、体组成及脂肪沉积的影响。采用3×2双因子实验设计,其中饲料脂肪水平分别为9%、12%和15%,投喂频率分别为2次/天和1次/天。结果表明:投喂频率对大黄鱼特定生长率(SGR)和饲料效率(FER)均有显著影响(P<0.05),而饲料脂肪水平仅对FER有显著影响(P<0.05)。2次/天投喂组的大黄鱼末体质量和SGR均显著高于1次/天投喂组,而饲料效率显著低(P<0.05)。在2次/天投喂时,各个饲料脂肪水平对SGR和FER没有显著影响(P>0.05)。而在1次/天投喂时,随着饲料脂肪水平的提高,SGR和FER均显著提高(P<0.05)。2次/天投喂组的大黄鱼全鱼水分含量显著低于1次/天投喂组,而粗脂肪含量显著高(P<0.05)。大黄鱼全鱼粗脂肪含量随着饲料脂肪水平的增加而显著升高(P<0.05)。然而在1次/天投喂时,饲料脂肪水平未对全鱼体粗脂肪含量产生显著影响(P>0.05)。大黄鱼的肝脏和肌肉脂肪含量、肝体比(HSI)以及脏体比(VSI)受到了饲料脂肪水平的显著影响(P<0.05)。在2次/天投喂时,肝脏和肌肉脂肪含量、HSI以及VSI随饲料脂肪水平的升高而显著增加(P<0.05);而在1次/天投喂时,各个饲料脂肪组大黄鱼肝脏和肌肉脂肪含量、HSI以及VSI均无显著差异(P>0.05)。饲料脂肪水平和投喂频率仅对大黄鱼的生长、饲料效率的影响存在显著的交互作用(P<0.05),而对大黄鱼体组成、形态学指标以及肝脏和肌肉脂肪含量无显著的交互作用(P>0.05)。  相似文献   

3.
对异育银鲫进行饥饿2周后恢复投喂处理,分析体质量(107.2±7.0)g的异育银鲫的生长率及卵巢发育相关指标的变化.结果表明,饥饿处理2周后,异育银鲫恢复投喂2周,特定生长率显著高于投喂组,体质量增长接近正常投喂组,出现完全补偿生长.在饥饿过程中,卵巢发育相关指标性腺成熟系数、肝体指数、血清磷含量、血清钙含量均呈下降趋势.饥饿1周,性腺成熟系数显著低于投喂组水平;饥饿2周,肝体指数血清磷、血清钙含量和血清钙含量均极显著低于投喂组水平.恢复投喂后,4项指标均有一定程度的恢复,仍显著低于投喂组水平.说明异育银鲫饥饿2周后恢复投喂2周,其卵巢发育的恢复滞后于身体的生长.  相似文献   

4.
为探讨大杂交鲟(Huso dauricus♀×Acipenser schrenckii♂)适宜投喂率和投喂频率,本实验分别设计了5个投喂率(0.4%、0.8%、1.2%、1.6%和2.0%)和5个投喂频率(1次/d、2次/d、3次/d、4次/d和5次/d),研究不同投喂率和投喂频率对大杂交鲟生长、体成分和生化指标的影响。投喂率实验中鱼初重(335.87±0.82)g,投喂频率实验中鱼初重(334.77±1.06)g,养殖周期为10周。结果表明,随着投喂率升高,实验鱼增重率、特定生长率、肝体比、脏体比、肥满度,肌肉粗蛋白、粗脂肪和肝粗脂肪含量显著升高(P0.05),血清谷丙转氨酶、谷草转氨酶和胃蛋白酶活性均显著升高(P0.05);饲料效率、全鱼和肌肉水分含量均显著降低(P0.05);全鱼粗脂肪含量,血清总蛋白、白蛋白和高密度脂蛋白胆固醇含量,肠脂肪酶活性呈先升高后降低趋势(P0.05)。随着投喂频率增加,实验鱼增重率、特定生长率和饲料效率无显著差异(P0.05);1次/d投喂频率组脏体比、肥满度和全鱼粗脂肪含量显著低于其他各组(P0.05),2次/d投喂频率组全鱼粗蛋白含量显著高于其他各组(P0.05)。不同投喂频率对实验鱼除血清葡萄糖含量以外的其他血清生化指标和胃肠消化酶活性或含量均无显著影响(P0.05)。综合以上结果认为,在300～600g大杂交鲟的养殖过程中日投喂率在1.2%～1.6%,投喂频率为2次/d比较适宜。  相似文献   

5.
大黄鱼幼鱼对饲料中锌需要量   总被引：1，自引：1，他引：0  
以初始体重为(1.78±0.02)g的大黄鱼为实验对象,在室内流水系统(养殖桶规格:200L)中进行为期8周的摄食生长实验,研究大黄鱼对饲料中锌的需要量.通过在基础饲料中添加ZnSO4·H2O使饲料中锌含量分别达到9.68、30.63、48.94、91.28、167.49和326.81mg·kg-1.每种饲料设3个重复,每个重复放养40尾大黄鱼.实验采取饱食投喂方式,每天投喂2次(05:30和17:30),实验期间水温为26.5～29.5℃,盐度为25～28,溶解氧含量在7mg·L-1左右.实验结果表明各饲料处理组成活率(84.2%～96.7%)无显著差异.随着饲料中锌含量的增加,大黄鱼的特定生长率(SGR)显著升高[(2.47～2.77)%·d-1,P<0.05],且在91.28mg·kg-1锌饲料组达最大值(2.77%·d-1),然而,随着饲料中锌含量的进一步增加,SGR维持在一相对稳定水平,各处理组间体蛋白(14.0%～15.0%),体脂肪(5.4%～6.1%),灰分(3.7%～4.1%)及水分含量(76.1%～77.9%)均无显著差异(P0.05).饲料锌含量显著影响大黄鱼脊椎骨、全鱼和血清中锌的含量,而对肝脏锌含量无显著影响.以SGR与骨骼锌含量为评价指标,根据折线模型得出大黄鱼对饲料中锌的需要量分别为59.6和84.6mg·kg-1.  相似文献   

6.
以酪蛋白和明胶为蛋白源,七水硫酸锌为锌源,在基础饲料中分别添加锌0,50,100,150,200,400mg/kg,制成6种含有不同锌水平的精制饲料(19.95,71.06,118.50,174.00,226.10和411.20mg/kg),投喂初始体重为(62.89±0.51)g的星斑川鲽幼鱼66d,研究饲料锌水平对星斑川鲽幼鱼生长、体成分、组织锌积累及抗氧化能力的影响。结果表明,随着饲料锌水平的增加,星斑川鲽的增重率(WGR)显著升高(P<0.05),在174.00mg/kg锌饲料组达最大值,而锌水平高于174.00mg/kg时,其增重率和特定生长率(SGR)变化不显著(P>0.05),SGR和WGR的变化趋势相同,且SGR的最大值及饲料系数(FCR)的最小值均出现在174.00mg/kg锌饲料组;全鱼营养成分各处理组间均无显著差异(P>0.05),锌添加量为0mg/kg饲料组的肌肉脂肪含量显著高于其它各组(P<0.05);411.20mg/kg锌饲料组的全鱼、脊椎骨和肌肉中锌积累量显著高于其它各组(P<0.05),当饲料锌水平为118.50～411.20mg/kg时,全鱼、脊椎骨和血清中锌积累量显著高于...  相似文献   

7.
刘伟  文华  蒋明  吴凡  田娟  杨长庚  黄凤 《水产学报》2016,40(5):751-762
为探讨饲料蛋白质水平与投喂频率对罗非鱼生长及生理健康的影响,采用2×3双因子实验,研究饲料蛋白质水平(36.27%和26.02%)与投喂频率(1、2和3次/d)对吉富罗非鱼幼鱼生长、体成分、血清指标和肝胰脏结构的影响。养殖周期为42 d,结果表明:随饲料蛋白质水平的增加,实验鱼的末体质量(FW)、增重率(WGR)、特定生长率(SGR)、饲料效率(FE)、肥满度(CF)、去内脏全鱼灰分(EWA)、内脏水分(VM)、高密度脂蛋白胆固醇(HDLC)水平显著升高(P0.05),而摄食率(FI)、脏体比(VSI)、饲料成本(FC)、去内脏全鱼粗脂肪(EWF)、内脏粗脂肪(VF)、肝胰脏粗脂肪(HF)显著降低(P0.05);随投喂频率的增加,实验鱼的FW、WGR、SGR、肝体比(HSI)、CF、FC、EWF、VF、HF,血清中的总胆固醇水平(TCHO)、HDLC、低密度脂蛋白胆固醇(LDLC)、总蛋白(TP)、甘油三酯(TGK)水平显著升高(P0.05),而FE、蛋白质效率(PER)、去内脏全鱼水分(EWM)、EWA、VM、肝胰脏水分(HM)显著降低(P0.05)。饲料蛋白质水平和投喂频率对实验鱼的FW、WGR、SGR、VM和HDLC的交互作用显著(P0.05)。投喂26.02%蛋白质水平饲料的实验鱼,肝胰脏细胞肿大变形,呈现透明的空泡化,出现细胞核偏移;而投喂36.27%蛋白质饲料的实验鱼,大多数肝细胞胞浆清晰,可观察到的肝细胞空泡面积较小。综合考虑,饲料蛋白质含量为36.27%是适合吉富罗非鱼幼鱼的,其适宜的投喂频率为2次/d以上,可根据罗非鱼市场情况进行调节。  相似文献   

8.
通过测定凡纳滨对虾(Litopenaeus vannamei)生长性能和监测池塘水质变化,研究分段养殖模式在对虾养殖过程中的应用价值。养殖实验在6口池塘内(0.267 hm~2/口)进行,首先在其中2口池塘内进行对虾的中间培育,养殖密度为300×104尾/hm~2。经过36 d和48 d的中间培育后,将对虾先后转移到其他4口池塘内,养殖密度为60×10~4尾/hm~2,分别记为T_1和T_2组。剩余的对虾继续养殖在中间培育池塘内,记为C组。结果显示,经过分段养殖的T_1和T_2组对虾,在分池养殖阶段7 d内,生长速度均明显增加,其特定生长率(SGR)分别达到9.36%/d和6.76%/d;养殖期间,T_1组具有最大的SGR(9.36%/d)和饲料投喂量,然而其饲料系数(FCR)(1.053)高于T_2组(0.822);经过分段养殖的对虾FCR均低于C组(1.082)。在分池养殖阶段的大部分时间,T_2组对虾的SGR高于T_1组;C组NH4+-N、NO_2--N和Chl-a浓度低于T_1组和T_2组,而颗粒物含量(T_PM)和总磷(T_P)高于T_1组和T_2组;T_2组Chl-a含量明显高于T_1组和C组。结果显示,经过48 d中间培育后,即对虾体重约为2 g时进行分池养殖仍可保证对虾在较长时间内保持较大的生长速度,对于饲料的节约具有重要意义。由于分池养殖阶段具有较多的饲料投喂,经过36 d中间培育后的对虾具有最大产量。分池养殖池塘内饲料投喂少于全期养殖,有利于养殖系统的稳定,然而单位时间内投喂量增加则会影响水质。分段养殖模式在提高分池养殖阶段对虾的生长速度和保持水质稳定方面具有重要的应用价值。  相似文献   

9.
以初始平均体重(114.71±3.631)g、体长(15.70±0.352) cm的点篮子鱼为研究对象,探讨不同的投喂频率对其生长性能及体成分的影响.结果表明,投喂频率对点篮子鱼的存活率没有显著影响(P＞0.05),试验期间各个试验组存活率均为100％.而投喂频率对点篮子鱼的特定生长率(SGR)、日均增重(DWG)和增重率(WG)有显著影响(P＜0.05).每天投喂1次(F1)到4次组(F4)的点篮子鱼的SGR、DWG和WG随投喂频率的增加而显著性升高,而每天投喂5次组(F5)的SGR、DWG和WG显著低于F4组.随着投喂频率的提高,点篮子鱼的摄食率(FR)逐渐上升.饵料系数(FCR)与投喂频率呈正相关.鱼体水分和灰分含量随着投喂频率的增加而下降,F1到F4组间有显著性差异(P＜0.05),F4到F5无显著性差异.各试验组鱼体蛋白质含量无显著变化,而脂肪含量随投喂频率增加显著增加(F1到F4组间差异显著(P＜0.05),F4与F5无差异).综合本试验点篮子鱼的生长性能、饲料转化率和体成分变化,认为人工养殖点篮子鱼的最适投喂频率为4次/d.  相似文献   

10.
初始体重差异对黄颡鱼补偿生长的影响   总被引：1，自引：0，他引：1  
将黄颡鱼(Pseudobagrus fulvidracoR ichardson)按初始体重不同分为大(L)、小(S)两种规格(平均体重分别为11.79 g和2.76 g),在水温(28±1)℃、自然光照条件下,研究了初始体重差异对其补偿生长的影响。试验为期4周,每种规格设定3组,第1组为对照组,整个试验期间正常投喂;第2组第1周正常投喂,第2周停止投喂,后2周恢复投喂;第3组前两周2停止投喂,后2周恢复投喂。大规格鱼的3组分别以LC(对照组)、LD1和LD2表示,小鱼分别以SC(对照组)、SD1和SD2表示。结果显示:整个试验结束时,两种规格试验鱼试验组的体重均未赶上对照组,但各组的特定生长率在恢复生长过程中均显著高于对照组,表现为部分补偿生长;L规格鱼的补偿生长主要通过显著提高饲料转化效率和摄食率实现,S规格鱼通过显著提高摄食率实现;试验结束时,除LD2组的脂肪含量显著较低外,其余各组的鱼体生化成分与对照组无显著差异。  相似文献   

11.
No abstract available for this article.  相似文献   

12.
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.  相似文献   

13.
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).  相似文献   

14.
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15.

16.
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.  相似文献   

17.
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.  相似文献   

18.
In an investigation of the potential for pearl production in New South Wales (NSW), Australia, changes in the physical and reproductive condition of the pearl oyster, Pinctada imbricata, were monitored for over 2 years. Using wild oysters gathered from close to the southern extent of the species' range in Port Stephens, NSW, a series of macroscopic and histological observations were made. Reproductive activity in P. imbricata was greatest from late spring to early autumn with oysters in poor reproductive condition during winter. Peaks in reproductive indices occurred in November 1998, March 1999, December 1999 and April 2000. Four indices of physiological condition were used: shell growth, byssal attachment, mantle thickness and mucoprotien layer. With the exception of the thickness and extent of the mucoprotein layer, these indices either showed little variation or the variation that occurred was not related to seasonal or reproductive changes. Changes in the mucoprotein layer were correlated with water temperature and suggest that this layer is metabolized during periods of high demand such as during gonadogenesis. Collectors deployed at two sites in Port Stephens demonstrated that spatfall occurs largely in the months of December and January following the spring and early summer peaks in reproductive activity (November 1998 and December 1999). Spatfall was not observed following the autumnal peaks (March 1999 and April 2000) in reproductive activity. Overall, reproductive patterns in P. imbricata are poorly suited to spat supply in Port Stephens. Farmers require spat in early spring (September) to allow maximum use of the ‘growing’ season (September–May). Reproductively capable oysters are not available from the wild until September and quantity of natural spatfall is too variable and occurs too late in the season (December–January). As a result, oysters are being conditioned in the hatchery in July, spawned in August and spat are supplied to farmers in mid September.  相似文献   

19.
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20.
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。  相似文献   

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