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1.
利用封闭呼吸室对同一日龄、不同规格的红鳍东方鲀、菊黄东方鲀和菊黄东方鲀(♀)×红鳍东方鲀(♂)杂交F1代幼鱼进行耗氧率和临界窒息点的研究。试验结果表明,水温14.8～15.6℃时,体质量(37.24±3.64)g的红鳍东方鲀幼鱼耗氧率为(0.3385±0.0161)mg/(g.h),体质量(14.45±1.08)g的菊黄东方鲀幼鱼耗氧率为(0.2327±0.0241)mg/(g.h),体质量(27.96±1.38)g的杂交F1代东方鲀幼鱼耗氧率为(0.2282±0.0219)mg/(g.h);同一日龄不同规格红鳍东方鲀、菊黄东方鲀和杂交东方鲀幼鱼的耗氧量分别为(12.5243±0.6720)、(3.3544±0.2975)、(5.8469±0.9537)mg/(h.尾);3种东方鲀的耗氧率呈明显的昼夜节律,白天平均耗氧率显著高于夜晚。水温为14.8～15.6℃时,红鳍东方鲀、菊黄东方鲀及杂交东方鲀幼鱼的临界窒息点分别为0.665、0.882mg/L和0.774mg/L。 相似文献
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比较投饵率水平分别为3%、4%、5%、6%时,对暗纹东方鲀幼鱼生长、饲料效率的影响,以确定暗纹东方鲀幼鱼阶段的适宜投饵率。在23℃下,对规格为3.45～3.56g的暗纹东方鲀幼鱼进行30d的生长实验,结果表明:不同投饵率对暗纹东方鲀幼鱼的特定生长率、质量相对增加率、饲料效率、存活率均有显著影响(p<0.05);暗纹东方鲀幼鱼的适宜投饵率为4%,在投饵率为4℅时,质量相对增加率为116.04±0.04%,饲料效率达83.70±0.02%,特定生长率为111.49±0.03%/d,存活率为84.44±0.02%。 相似文献
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本试验研究了上海地区低盐度条件下池塘单养和混养对点篮子鱼（Siganus guttatus）幼鱼生长和摄食的影响.平均体重1.14±0.63g、平均体长3.57±0.88 cm的点篮子鱼,经90d的养殖后,单养点篮子鱼成活率82.86％,平均体重增加到55.08 ±14.21 g,平均体长增加到11.39±1.19 cm,最大规格体重达101.42 g;与拟穴青蟹（Scylla paramamosain）混养点篮子鱼成活率85.26％,平均体重增加到56.37 ±4.60 g、平均体长增加到11.60 ±0.42 cm,最大规格达118.71 g,拟穴青蟹平均体重从0.04g增长到209.88 g,最大规格达350.13 g.结果表明,在本试验条件下,混养模式中的点篮子鱼的存活率较单养模式高,生长摄食情况好,增重速度快,且摄食率低而饲料转化效率高. 相似文献
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本实验以平均初始体重为15.60 g的红鳍东方鲀(Takifugu rubripes)幼鱼为研究对象,研究饲料中蛋白含量及养殖密度对红鳍东方鲀幼鱼生长性能、氮排泄及相关生理生化指标的影响。设计两因素三水平(2×3)实验,配制3种不同蛋白梯度(38.87%、45.55%和51.00%,干重)的等脂实验饲料,设置3个密度梯度为1.53 kg/m^3(0.196 m3体积的实验桶,每桶20尾鱼)、2.30 kg/m^3(每桶30尾鱼)和3.06 kg/m^3(每桶40尾鱼)。每组饲料设3个重复,养殖实验为期56 d,在室内流水系统内进行。结果显示,增重率在高、中蛋白组显著高于低蛋白组(P<0.05),但当饲料蛋白含量一定时,养殖密度对增重率没有显著性影响。饲料蛋白含量和养殖密度对鱼体常规成分没有显著性影响。当饲料蛋白一定时,高密度组的血清总蛋白和胆固醇含量显著高于中密度组(P<0.05)。血清总蛋白含量在低蛋白组显著高于中蛋白组(P<0.05)。血清碱性磷酸酶含量在低蛋白组显著高于高蛋白组(P<0.05)。饲料蛋白含量和养殖密度对红鳍东方鲀幼鱼的生长、氨氮排泄没有显著性交互作用。静水投喂3 h后,氨氮排泄率在高密度组显著高于低密度组(P<0.05)。研究表明,45.55%饲料蛋白质含量已经能够满足红鳍东方鲀幼鱼正常生长的需求。饲料蛋白含量和养殖密度对红鳍东方鲀幼鱼的生长性能和氨氮排泄没有显著性交互作用。 相似文献
5.
以福建冬季海上筏式吊笼养殖的仿刺参为对象,采用传统海带饲料和市面销售的凝胶状海参配合饲料对三种规格的仿刺参幼参(平均体质量分别为105.57、73.15和52.89 g)进行了为期60 d的投喂试验,比较了两种饲料对仿刺参幼参生长的影响。结果表明,传统海带饲料投喂组大、中、小三种规格仿刺参的特定生长率分别为(0.69±0.04)、(0.87±0.05)和(0.99±0.02)%·d-1,凝胶状海参配合饲料投喂组的特定生长率分别为(0.65±0.03)、(0.86±0.05)和(0.81±0.10)%·d-1。传统海带饲料投喂组小规格仿刺参的平均个体增重率和特定生长率均显著大于凝胶状配合饲料投喂组(P0.05),而两种饲料投喂组大、中规格间的差异不显著。因此,传统海带饲料可用于仿刺参海上筏式吊笼养殖生产,而凝胶状海参配合饲料可作为传统海带饲料的辅助饲料。 相似文献
6.
2010年5～7月在山东威海乳山杜家岛基地,采用陆基围隔生态学实验方法和正交设计法,在不投饵模式下进行刺参Apostichopus japonicus和龙须菜Gracilaria lemaneiformis混养实验。刺参密度分别为15、20、25ind/m2,龙须菜初始密度分别为0、180、360g/m2,比较了不同处理下幼参和龙须菜的生长存活情况,并定期检测环境营养盐的变化。结果表明,刺参平均日增重率(Md-wg)、特定生长率(SGR)受刺参密度的影响显著,受龙须菜密度的影响不显著,受刺参与龙须菜之间交互效应影响不显著;刺参密度为15ind/m2、龙须菜密度为360g/m2时刺参平均日增重率、特定生长率最大;刺参密度为25ind/m2、龙须菜密度为360g/m2时龙须菜产量最高,刺参密度为25ind/m2、龙须菜密度为180g/m2时龙须菜特定生长率最高。水质分析结果表明,刺参密度为15ind/m2时底泥总氮、总磷含量降幅最大。实验结果显示,龙须菜和刺参混养可在一定条件下改善水质条件,提高刺参的特定生长率,在本实验条件下刺参密度15ind/m2、龙须菜密度360g/m2的混养配比较合理,其生态互利效果最好。 相似文献
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《水产科学》2015,(9)
将初始体质量(5.07±0.45)g的仿刺参幼参放养在池塘内竹制的4m×4m×1.5m网格中,将夹有初始平均体长(31.7±10)cm,体质量(2.32±1.2)g的鼠尾藻和菊花心江蓠的聚乙烯苗绳均匀地系在网格竹竿骨架上。仿刺参初始放养密度为11头/m2,鼠尾藻和菊花心江蓠的密度分别为187.5g/m2、375g/m2、562.5g/m2、750g/m2和250g/m2、500g/m2、750g/m2、1000g/m2,后轮养的菊花心江蓠按密度从小到大分别放置于原混养鼠尾藻密度为187.5g/m2、375g/m2、562.5g/m2、750g/m2网格内。每隔15d检测一次不同轮养系统中仿刺参和藻类的生长及水体中叶绿素a,底泥中总氮、总磷和有机碳含量的变化。120d的饲养结果表明,轮养大型藻的仿刺参特定生长率高于单养对照组的仿刺参,混养鼠尾藻562.5g/m2后,轮养菊花心江蓠750g/m2的模式下,仿刺参的特定生长率显著高于对照组(P0.05);轮养水体中叶绿素a含量明显下降,大型藻净产量越高,水体中叶绿素a含量下降越明显;轮养组底泥中总氮、总磷和总有机碳含量均明显低于单养组(P0.05)。 相似文献
8.
温度对红鳍东方鲀能量收支和生态转化效率的影响 总被引：2，自引：0，他引：2
以玉筋鱼为饵料生物和最大摄食水平条件下,采用室内流水式实验,测定了不同温度下(13、16、19和25°C)红鳍东方鲀(平均体重为37.1±7.7g)的生态转化效率和能量收支各组分.结果表明,红鳍东方鲀的最大摄食率、吸收率、排泄能和总代谢能均随温度上升呈增长趋势.以湿重计算的特定生长率(SGRw)和生态转化效率(ECEw)则呈现先随温度增长而后下降的趋势,其与温度之间的关系可用二次方程描述.由回归方程计算出的特定生长率最大值出现在23.52℃,生态转化效率最大值出现在18.95℃.方差分析表明,红鳍东方鲀的能量分配模式随温度变化显著.排泄能分配率和代谢能分配率占摄食能的绝大部分67.8%～81.7%,随温度升高呈"U"形变化趋势,最低出现在16℃;生长能分配率则与之相反,最高分配率出现在19℃.不同温度下红鳍东方鲀的代谢能占了同化能的61.1%～73.5%,生长能占13.2%～23.2%.可见红鳍东方鲀基本上属于中等生长效率、中等代谢消耗型鱼类. 相似文献
9.
为探索利用盐场低产虾池开展红鳍东方纯养殖,我们从2000～2005年连续在天津汉沽区盐场虾池开展了红鳍东方鱼屯的养殖,在养殖中,我们在池塘中投入了南美白对虾、日本对虾进行混养,取得了很好的经济效益,现将红鳍东方鲀与南美白对虾、日本对虾混养技术和一些 相似文献
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11.
以初始体重为(6.77±0.01)g的仿刺参(Apostichopus japonicus Selenka)为实验对象,在基础饲料中添加1％不同分子量的壳聚糖,分子量分别为35 kDa和400 kDa,进行为期56d的养殖实验,研究低分子壳聚糖(LMWC)和高分子壳聚糖(HMWC)对仿刺参生长和免疫相关酶活性的影响.结果显示,不同分子量的壳聚糖对仿刺参的生长均有促进作用,且LMWC能显著促进刺参的特定生长率(SGR)(P＜0.05).饲料中添加不同分子量壳聚糖,刺参体腔细胞中的总超氧化物歧化酶(T-SOD)活性比对照组均显著增高(P＜0.05).LMWC可显著增强刺参体腔细胞中酸性磷酸酶(ACP)活性(P＜0.05),并能提高碱性磷酸酶(AKP)和一氧化氮合酶(NOS)活性.HMWC对刺参体腔细胞中AKP和NOS活性均有显著增强作用(P＜0.05).研究表明,在刺参饲料中添加一定量的壳聚糖,对其生长和相关免疫酶活性有促进作用. 相似文献
12.
Consumption and Assimilation of Salmon Net Pen Fouling Debris by the Red Sea Cucumber Parastichopus californicus: Implications for Polyculture 总被引：1，自引：0，他引：1
Abstract Fouling debris composed of fish feces, excess fish food, algae, and other particulate organic matter can create environmental problems for aquaculture facilities that rear fish in ocean net pens. Accumulations of organic debris can clog the nets and restrict water circulation which in turn can stress fish. Experiments in which red sea cucumbers Parastichopus californicus were allowed to feed inside floating net pens at a salmon rearing facility in Southeast Alaska showed that sea cucumbers consumed fouling debris and cleared a significant amount of surface area on the nets (P < 0.0001). Sea cucumbers assimilated amino acids and other organic matter from fouling debris two to three times more efficiently than from their natural sediment diet. Muscle development of sea cucumbers consuming fouling debris inside the net pens was also significantly greater than that of sea cucumbers feeding in their natural environment (P < 0.0003). This work suggests that polyculture operations in which commercially important detritivores, like the red sea cucumber, are grown in net pens along with salmon could possibly convert the net from self-fouling to self-cleaning and could turn fouling debris into a marketable product (sea cucumber biomass). 相似文献
13.
研究了不同饲料原料对刺参Apostichopus japonicus(Selenka)幼参生长和体成分的影响.实验采用鱼粉、鼠尾藻Sargassum thunbergii Kuntze、浒苔Enteromorpha prolifera、海带Laminaria japonica和海泥5种主要原料配制的饲料投喂体长为4.18±0.23cm、体重为5.99±0.26g的刺参幼参,进行了为期80d的养殖实验.实验结束时,投喂鼠尾藻饲料、浒苔饲料和动物性饲料的刺参特定生长率(SGR)分别为95.36%/d、92.29%/d和84.87%/d.这三者之间无显著差异,但生长效果要好于投喂海带饲料和海泥饲料的刺参.实验结果表明,在特定的室内养殖条件下,虽然刺参能够更好地利用植物性蛋白,但是可以将动物性蛋白作为刺参的辅助性饲料成分,配制出营养更全面的配合饲料;浒苔作为刺参幼参的养殖饲料原料是完全可行的;海带粗加工产品不适于用做刺参饲料的主要成分. 相似文献
14.
[目的]为了比较不同生产工艺得到的酶解鳀鱼浆（HFP）、鳀鱼鱼溶浆（SW）、酶解鳀鱼鱼溶浆（HSW）、低温烘干鳀鱼粉（L-FM）和常规烘干鳀鱼粉（H-FM）在饲料中的应用效果 。[方法]以初始体重为（17.69±0.09）g的黄颡鱼幼鱼为养殖对象 ,以30%的秘鲁超级蒸汽鱼粉（FM组）为对照,在试验日粮中分别添加酶解鳀鱼浆、鳀鱼鱼溶浆、酶解鳀鱼鱼溶浆、低温烘干鳀鱼粉和常规烘干鳀鱼粉,经过8周池塘网箱养殖试验,比较5种不同生产工艺得到的鳀鱼蛋白质原料对黄颡鱼生长性能的影响。其中,酶解鳀鱼浆在日粮中的添加量为FM组中鱼粉蛋白质量的25%（HFP25组）、45%（HFP45组）和65%（HFP65组）三个剂量梯度;以酶解鳀鱼浆组（HFP45组）添加的酶解鳀鱼浆蛋白含量为基准,与相同蛋白含量的鳀鱼鱼溶浆（SW组）和酶解鳀鱼鱼溶浆（HSW组）进行生长比较;低温烘干鳀鱼粉和常规烘干鳀鱼粉添加量为30%;以上共计8组等氮等脂 日粮,每组设置3个重复,每个重复40尾。[结果]试验结果显示：1）与FM组相比,L-FM和H-FM组的SGR和FCR均无显著差异（P>0.05）;2）以FM组为对照,HFP25试验组的SGR降低了3.30%,FCR升高了5.36%,无显著差异（P>0.05）,而HFP45和HFP65组的SGR分别降低了10.99%、20.33%,FCR分别升高了21.43%、41.96%,差异显著（P<0.05）,并且随着日粮中HFP添加量的增加,SGR、蛋白沉积率（PRR）和脂肪沉积率（FRR）均呈现下降趋势,差异显著（P<0.05）;3）HFP45、SW、HSW三组试验饲料的结果为：HFP具有最高的SGR,而SW的SGR最低,差异不显著（P<0.05）。经酶解处理后的HSW相比SW组SGR升高了2.25%,差异不显著（P>0.05）,体组成方面,鱼体水分、蛋白、脂肪和总磷含量变化不显著（P>0.05）,灰分变化显著（P<0.05）。[结论]研究表明：秘鲁超级蒸汽鱼粉（FM）、低温烘干鳀鱼粉（L-FM）和常规烘干鳀鱼粉（H-FM）在黄颡鱼生长性能和饲料利用效率方面无显著性差异,但低温烘干鳀鱼粉在黄颡鱼鱼体健康方面优于常规烘干鳀鱼粉;在黄颡鱼日粮中实际添加7.1%的酶解鳀鱼浆可以完全替代30%的鱼粉, 在鱼体生长速度、饲料效率和血清指标等方面具有一定的等效性;日粮中过高添加量的酶解鳀鱼浆会导致黄颡鱼生长速度和饲料效率的下降;不同酶解蛋白原料中,酶解鳀鱼浆（HFP）对黄颡鱼的生长效果最好,鳀鱼鱼溶浆（SW）生长效果最差。此外,经酶解处理后的酶解鳀鱼鱼溶浆（HSW）要优于鳀鱼鱼溶浆（SW）。 相似文献
15.
本研究比较分析了在对照组(pH为8.4)、低pH胁迫组(pH为6.8、7.0、7.2、7.4、7.6和7.8)和高pH胁迫组(pH为8.6、8.8、9.0、9.2、9.4和9.6)的养殖水环境下,胁迫36 d对刺参(Apostichopus japonicus Selenka)存活、生长及抗氧化酶活性的影响。结果显示,不同pH对刺参存活、生长及抗氧化酶活性有显著影响。在pH 7.4~9.0范围内,刺参存活率为100%,随着pH胁迫强度和胁迫时间的增加,刺参存活率逐渐降低,当pH为6.8、7.0和9.6时,自第3天起,刺参处于过度应激状态,继而有死亡个体出现,至30 d时刺参死亡率为100%。不同pH显著影响刺参生长,刺参特定生长率随pH胁迫程度增加呈下降趋势,当pH为9.0时,刺参出现负增长。各pH胁迫组刺参超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均高于对照组,且随pH胁迫程度的增加呈先升高后下降的变化趋势。在低pH组中,以pH=7.4时刺参SOD和CAT活性最高,分别达到(74.92±2.24)U/ml和(14.99±2.38)U/ml,显著高于对照组;而在高pH组中,SOD和CAT活性分别以pH 8.8和9.0时最高,分别达到(72.90±1.10)U/ml和(15.68±0.89)U/ml,显著高于对照组。结果表明,pH在7.4~9.0范围内是刺参存活与生长的适宜水环境,过高或过低均会引起刺参不同程度的应激反应,进而导致刺参的死亡。 相似文献
16.
在室内条件下进行了玉足海参与凡纳滨对虾的混养实验,分析了单养与混养两种条件下养殖水体营养盐结构以及底质成分的变化,测定了对虾与海参的存活率与生长性能。结果显示,混养海参可以明显改变养殖系统的营养盐结构,可使水体中的磷酸盐和硝酸盐浓度有所升高,同时也可有效地控制系统中氨氮浓度。混养海参也可以大幅度地降低沉积物中有机质和硫化物含量,实验结束时混养组硫化物含量为(7.71±1.33)mg/kg,仅相当于单养组浓度的1/3。混养海参对对虾生长及存活具有明显的促进作用,其中混养组对虾体长特异增长率为(0.69±0.13)%/d,显著优于单养组(0.45±0.06)%/d;混养组对虾成活率可达72.5%±22.9%,显著高于对照组55.0%±17.5%。在混养系统内,对虾不会对海参的生存造成负面影响,海参能够有效地选择摄食和利用沉积物中的营养物质(对食物中有机质的同化率可达36.36%±13.79%),并以较快的速度生长。结果表明,在对虾养殖系统中混养玉足海参具有明显的环境与经济效益。本研究可为我国海水养殖业的可持续发展提供一定的科学依据。 相似文献
17.
Effects of Dietary Fish Oil Replacement with Palm Oil on the Growth,Feed Utilization,Biochemical Composition,and Antioxidant Status of Juvenile Chu's Croaker,Nibea coibor 
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下载免费PDF全文 Yisheng Huang Xiaobo Wen Shengkang Li Wenjia Li Dashi Zhu 《Journal of the World Aquaculture Society》2016,47(6):786-797
A 56‐d feeding trial was conducted to evaluate the growth performance, feed utilization, biochemical composition, and antioxidant status of chu's croaker, Nibea coibor (12.6 ± 0.1 g) in net pens fed diets supplemented with various levels of crude palm oil: 0% fish oil (FO), 20% palm oil (2PO), 40% (4PO), 60% (6PO), 80% (8PO), and 100% (10PO). Weight gain and specific growth rate (SGR) were significantly lower in fish fed 8PO and 10PO diets. The increase of PO levels did not affect fish survival, feed intake, and feed conversion ratio. Feeding diet 10PO led to significantly higher lipid content in the liver, but not the whole body and dorsal muscle, than diets FO and 2PO. PO supplementation led to increased α‐tocopherol, but decreased thiobarbituric acid‐reactive substances, n‐3 highly unsaturated fatty acid (n‐3 HUFA), and n‐3/n‐6 fatty acid ratio, in both the liver and muscle. Hepatic superoxide dismutase and catalase were significantly higher in fish fed 10PO diet than FO diet. Polynomial regression analysis showed that the maximum SGR was obtained at 24.2% crude PO. Results of this study suggested that PO could replace up to 60% of FO without adverse effect on growth performance or nutritional quality of fish. 相似文献
18.
《Journal Of Applied Aquaculture》2013,25(3-4):133-142
Abstract Attempts to rear summer flounder, Paralichthys dentatus, in net pens have suffered from high mortality during the month after fish were transferred from a nursery facility to pens. We investigated whether exposing summer flounder to increased (and constant) current velocity in the nursery stage would condition them for better performance in cages. Three experiments were conducted with different water velocities in tanks, using fish of 124±4 g (exposed to 0, 15, or 30 cm/sec for 60 d), 257±12 g (exposed to 0, 20, or 40 cm/sec for 60 d) and 387±13 g (exposed to 0, 15, or 30 cm/sec for 30 d), in a raceway system with adjustable paddlewheels. For all of the size groups of fish, survival was significantly reduced at the highest current velocity. For both 124-g and 257-g fish, growth in the medium-velocity treatment was significantly better than that in the control (0 cm/sec) treatment, which in turn was better than that in the high-velocity treatment. For 387-g fish, growth at medium velocity was significantly greater than that at high velocity; control fish were lost due to a system malfunction. Food consumption data from the 257-g fish showed that the fish in medium velocity grew most because they consumed significantly more food during the experiment than did fish in the control, which in turn consumed significantly more than fish in high velocity. Similarly, 387-g fish in medium velocity consumed the most food, but the difference was not significant in this case. At the end of the laboratory experiment with 124-g fish, fish from the control and medium-velocity treatments were moved to cages in Narragansett Bay, Rhode Island, where currents of about 1 knot (approx. 55 cm/second) are routine. After three weeks in the cages, no significant differences in survival were observed (control = 83±12%; medium velocity = 81±2%). Subsequent damage to some of the cages and escapement of the fish precluded further statistical analysis of survival, as well as any growth measurements. At the end of the laboratory experiment with 387-g fish, fish from medium- and high-velocity treatments were moved to the cages; however, survival in this case was very low (<10% in all cages), perhaps due to heavy waves from an offshore hurricane. We conclude that current velocities of 15-20 cm/second in the nursery improve growth of juvenile summer flounder, that current velocities of 30-40 cm/second are excessive, but that increased current velocity in the nursery does not improve fish survival upon transfer to cages. 相似文献
19.
The system nitrogen (N), phosphorous (P) budget, N/P utilization rate and the physiological response mechanism of the abalone Haliotis discus hannai (body weight: 12.87 ± 0.82 g) and the sea cucumber Apostichopus japonicus (body weight: 10.85 ± 1.16 g) to different co‐culture environment conditions were examined. Animals were kept in a multilayer, cubic recirculating aquaculture system at different polyculture densities (abalones at 400 ind/m2in monoculture [Group C] and abalones at 400 ind/m2with sea cucumbers at 10 ind/m2 [AS1] or 20 ind/m2 [AS2]). Each treatment was replicated four times, and the experimental cycle was 90 days. No significant difference in survival rate of abalones was detected when the stocking density of sea cucumbers increased from 10 to 20 ind/m2, but the concentrations of total ammonia nitrogen and nitrite nitrogen in the water were significantly higher in AS2 than in AS1. Survival rate, specific growth rate (SGR) of body weight of sea cucumbers and SGR of body weight of abalones were significantly lower in AS2 than in AS1. No significant difference in protease (PES), lipase, amylase and cellulase activities of abalones was identified between Group C and AS1, but the PES and amylase activities of abalones and sea cucumbers in AS1 were significantly higher than those in AS2. In AS1, the N/P output from harvesting of abalones and sea cucumbers and the N/P utilization rates were significantly higher than those in AS2. Although the N/P output from faeces was significantly lower in AS2 than in Group C and AS1, the N/P output from the water layer was significantly higher than that in AS1. The expression levels of Cu/Zn superoxide dismutase (Cu/Zn‐SOD) and heat shock protein 70 (HSP70) of both abalones and sea cucumbers in AS2 were significantly higher than those in AS1. No significant difference in expression of catalase (CAT) and HSP90of abalones was identified among these groups, but the expression levels of CAT and HSP90of sea cucumbers in AS2 were significantly higher than those in AS1. These results indicate that stocking sea cucumbers at 10 ind/m2 in the polyculture system will relieve the organic load on the system and improve the N/P utilization rate. It will also increase aquaculture production and improve the ecological and economic benefits of the system. 相似文献
20.
Jason J. Danaher James H. Tidwell Shawn D. Coyle Siddhartha Dasgupta Paul V. Zimba 《Journal of the World Aquaculture Society》2007,38(3):367-382
The effects of different densities of caged Nile tilapia, Oreochromis niloticus, on water quality, phytoplankton populations, prawn, and total pond production were evaluated in freshwater prawn, Macrobrachium rosenbergii, production ponds. The experiment consisted of three treatments with three 0.04‐ha replicates each. All ponds were stocked with graded, nursed juvenile prawn (0.9 ± 0.6 g) at 69,000/ha. Control (CTL) ponds contained only prawns. Low‐density polyculture (LDP) ponds also contained two cages (1 m3; 100 fish/cage) of monosex male tilapia (115.6 ± 22 g), and high‐density polyculture (HDP) ponds had four cages. Total culture period was 106 d for tilapia and 114 d for prawn. Overall mean afternoon pH level was significantly lower (P ≤ 0.05) in polyculture ponds than in CTL ponds but did not differ (P > 0.05) between LDP and HDP. Phytoplankton biovolume was reduced in polyculture treatments. Tilapia in the LDP treatment had significantly higher (P ≤ 0.05) harvest weights than in the HDP treatment. Prawn weights were higher (P ≤ 0.05) in polyculture than prawn monoculture. These data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas. 相似文献