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1.
利用0.53 hm^2池塘试养红螯螯虾,放养体长1.5 cm红螯螯虾虾苗2万尾,收获红螯螯虾975 kg,另外收获河蟹175 kg、青虾36 kg、鲫鱼190 kg,总利润68420元。饲料系数为0.72,红螯螯虾成活率为65%。结果认为:红螯螯虾可单养,亦可与河蟹、青虾等混养;水草覆盖率80%是适宜的。  相似文献   

2.
克氏原螯虾幼虾培育技术研究   总被引:1,自引:0,他引:1  
对克氏原螯虾幼虾进行培育,即克氏原螯虾从破膜再经3次蜕皮体长到0.9~1.0cm后(即仔虾离开母体后)进行培育,经22d培育试验,幼虾体长平均从1.0 cm增长到3.0 cm,体重平均从0.012 g增重到1.64g.采取两种培育方式(即繁殖池原池培育和幼虾池培育),其成活率平均分别为75.6%和71.2%.  相似文献   

3.
熊青海  韦维婷  夏爱军  黄成 《水产科技情报》2011,38(3):109-111, 114
在实验室条件下,对比研究了克氏原螯虾受精卵在离体条件和抱卵条件下的孵化成功率,以及仔虾在与雌性亲虾隔离和共栖条件下的存活与生长情况,以探讨克氏原螯虾母性抚育行为和食仔行为对子代的影响.研究结果表明:克氏原螯虾的亲虾抚育可以显著(P<0.05)提高受精卵的孵化成功率;雌性食仔行为对仔虾的体长和体长变异系数无显著影响(P>0.05),但会显著降低(P<0.05)仔虾的存活率.  相似文献   

4.
熊青海  陈婷  郭建英  黄成 《水产科学》2012,31(3):147-151
研究了洞穴、角落、空旷3种生境下,克氏原螯虾与中华绒螯蟹混养的存活率和残肢率,以探究两者的种间竞争情况;采集在室外池塘下,虾蟹混养和克氏原螯虾单养的克氏原螯虾收获量、回捕率,分析自然条件下两者的种间竞争情况。结果显示,混养时克氏原螯虾在洞穴型和空旷型生境下,存活率显著提高,残肢率显著下降;而中华绒螯蟹的存活率则显著下降,在洞穴型生境下残肢率显著提高;在角落型生境下,虾、蟹混养会导致克氏原螯虾存活率显著降低,对中华绒螯蟹的存活率无显著影响;在野外池塘条件下,虾蟹混养组最终的克氏原螯虾收获量和克氏原螯虾单养组并无显著性差异。  相似文献   

5.
食用罗氏沼虾养殖中放养模式研究的进展   总被引:2,自引:1,他引:1  
王吉桥 《水产科学》1996,15(5):18-25
本文综述了近年来国内外有关食用罗氏沼虾(Macredrachiumrsenbergii)的放养密度、规格和分规格饲养等方面的技术和理论的最新资料。作者认为,罗氏沼虾单养或混养时分别放养体长2~3cm的仔虾12~20万尾/hm2或5~8万尾/hm ̄2,采用双或三规格饲养法较为适宜。  相似文献   

6.
《广西水产科技》1979,(4):18-18
为了摸索罗氏沼虾养殖方法,今年5月份进行了以虾为主,鱼虾混养试验。面积1.47亩,水深80—100厘米,泥底。第一批于5月25日放养体长为1.7—3厘米小虾14000尾,同时放养平均半斤重的鳙鱼种58尾,2—3两重的草鱼10尾。第二批于6月19日放养小虾1400尾,第三批于7月4日放养2—3厘米小虾600尾。三批共放养16000尾,重9.9斤。  相似文献   

7.
2个凡纳滨对虾群体仔虾的生长比较   总被引:3,自引:0,他引:3  
以凡纳滨对虾二代群体自交、选育家系(♀)×引进SPF(♂)群体杂交,通过自然交配和人工培育获得2个仔虾群体,待仔虾长至体长0.8~1.0 cm时,随机选取60万尾放养于3口0.133 hm2的对虾养殖高位塘中,密度150万尾/hm2,其中二代仔虾2口塘,杂交仔虾1口塘.投喂"恒兴"牌饲料,相同的养殖环境和管理措施,养殖30 d后,每隔10 d进行一次生长测定.结果表明,杂交仔虾的生长速度和成活率高于二代仔虾,体质量和体长的总生长率高于二代仔虾,抗应激能力强于二代仔虾,较二代仔虾均匀;在40 d的观测期内杂交仔虾体长的绝对增长量为4.49 cm,二代仔虾为3.66 cm,提高22.68%,杂交仔虾体质量的绝对增长量为3.73 g,二代仔虾为2.20 g,提高69.55%,杂交仔虾生长优势明显.  相似文献   

8.
1 基本情况与主要技术1.1 试验选择陡湖区域4个条件基本一致的池塘,分别按螯虾单养,鱼、螯虾混养,河蟹、螯虾混养,鱼、河蟹、螯虾混养四种模式进行。池口面积20~21亩,平均20.4亩,池深均约1.5m,坡比均1:2.5左右,水草丰盛。4个池3月5日统一干塘清塘,每亩  相似文献   

9.
《淡水渔业》2021,51(5)
为几种克氏原螯虾(Procambarus clarkii)养殖模式的优劣提供数据参考,对池塘单养克氏原螯虾、虾鱼混养、虾蟹混养、稻虾养殖四种模式进行比较,研究了其水体理化指标、幼虾生长、体成分、血淋巴生化等指标,试验周期60 d。结果表明:体长和体重均呈现虾单养组虾鱼组虾蟹组稻虾组;克氏原螯虾的体长增长率随时间大体呈逐渐下降的趋势;体重增长率和特定增长率则呈先升高后降低的趋势;虾单养组、虾鱼组及虾蟹组的体重增长率均在30 d达到最高,而稻虾组在40 d达到最高。四种养殖模式克氏原螯虾的体成分组成差异较大,全虾的粗蛋白含量虾蟹组显著高于另外三个组,粗脂肪含量虾单养组显著低于另外三个组,水分含量稻虾组显著高于虾单养组、虾蟹组,灰分稻虾组显著低于另外三个组。血淋巴生化指标分析表明虾蟹组和虾鱼组在总蛋白、白蛋白和血糖高于虾单养组和稻虾组,甘油三酯和转氨酶低于虾单养组和稻虾组。研究表明,从生长角度看虾单养组生长最快,从虾体成分看稻虾组最接近野生群体,从血清生化指标看虾蟹组最健康。  相似文献   

10.
为抵御单一养殖崇明清水蟹带来的风险,开展了崇明清水蟹与澳洲红螯螯虾高效生态混养试验。以2020年上海崇东水产养殖专业合作社的混养试验为例,养殖池塘面积1 hm~2,蟹种放养量12 000只,产量1 125 kg,澳洲红螯螯虾放养量15 000尾,产量450 kg,总产值31.5万元,利润20.1万元。结果表明,采用崇明清水蟹与澳洲红螯螯虾高效生态混养模式,不会影响清水蟹的产量,且单位面积利润比单养模式提高了34%,因此是1种生态效益和经济效益兼顾的养殖模式。  相似文献   

11.
Effects of size grading and stocking density on growth and survival of 3.5‐month‐old signal crayfish (Pacifastacus leniusculus Dana) juveniles were investigated in a 3 × 2 factorial design with size group (small, large and mixed) and stocking density (25 and 200 individuals m?2) as factors for 90 days. Carapace length and wet weight growth of the juveniles were affected by the presence or absence of other size groups, stocking density and animal size. All factors had statistically significant interactions, which make the interpretation of the results more complicated. The smaller crayfish grew faster in the absence of large animals and larger animals benefited from the presence of smaller cospecies. Increasing density decreased the growth in length and weight. Survival (82–100%) was good in all groups. Subsequently, the within population dynamics was studied by selectively removing the largest individuals (selectively removing (SR) group). Effects on growth and survival of the remaining juveniles were evaluated on 6‐month‐old P. leniusculus juveniles reared in plastic tanks (100 juveniles m?2) for 122 days. Size distribution manipulation was performed at days 34 and 70. Juveniles in SR group grew significantly faster in comparison with a control group (RR), from which juveniles were removed randomly. Also, the survival rate was significantly higher in the SR group than in the RR group. In conclusion, size grading of juvenile P. leniusculus either at the start of the experiment or repeatedly during the experiment increased growth performance of smaller animals in length and weight.  相似文献   

12.
Crayfish show both shelter‐seeking behaviour and agonistic behaviour. Agonistic interactions among crayfish combatants can be triggered and released by the access of shelter, which is a necessary resource for crayfish. The use of shadow as a shelter has not been thoroughly tested in experiments. In this study, we provided the Red Swamp Crayfish Procambarus clarkii (Girard) with different shadow area and shadow partition to test if shadow can act as a solid shelter. Eleven different treatments designed with different shadow area and partition, and 2640 juvenile crayfish were used. The survival rate increased with the increase of shadow area ratio. The shadow area contributed less to the body weight gain and the number of the survivals without injury. The growth variance of the juveniles under shadow conditions was significantly lower than those maintained without providing shadow. Under the recent experimental settings, generally, more partitioned shadow resulted in lower mortality. With 60% shadow area, more partitioned shadow led to higher body weight gain. The more the partition was provided, the fewer were the injury events, and the lower body weight variance observed. Our experiments indicated that both area and partition of the shadow influenced the growth of juvenile Red Swamp Crayfish.  相似文献   

13.
The inert marker method for individual food intake measurement of signal crayfish (Pacifastacus leniusculus Dana) juveniles (carapace length (CL) ranged from 16.5 to 25.6 mm and wet weight (WW) from 0.88 to 4.47 g) was evaluated in a series of experiments. The measurement technique was tested with two types of diet: a gelatin‐based semi‐moist diet and an agar‐based dry diet. Diets were labelled with X‐ray dense ballotini glass beads. After feeding, juveniles were X‐rayed, and the amount of ingested glass beads in the digestive track was counted from the X‐ray images. The method proved reliable only with the gelatin diet. In the ingested gelatin food, 92.80±8.55% of the glass beads originally in the food were found in comparison with 40.99±24.72% for the agar diet. Subsequently, the growth efficiency of the gelatin diet was compared with typically used raw fish diet (roach, Rutilus rutilus L.), and possible harmful effects of X‐raying on the growth and survival of the juveniles were tested on 2‐year‐old crayfish (CL 22.90±1.66 mm and WW 3.15±0.71 g). Roach‐fed juveniles grew significantly faster than the gelatin‐fed counterparts. However, the growth performance and survival of the juveniles on gelatin diet was considered good enough to allow long‐term growth experiments with individual feed intake monitoring, e.g. for studies on social behaviour of the crayfish. The results of this study confirmed that the X‐radiography technique together with a semi‐moist gelatin‐based diet makes it possible to measure individual food consumption of freshwater crayfish juveniles reared communally.  相似文献   

14.
As alternative to formalin, the antifungal effect of a plant product [Origanum onites L. (Lamiaceae) oil] was investigated for use in the artificial incubation of narrow‐clawed crayfish (Astacus leptodactylus Eschscholtz) eggs. For this purpose, this study was conducted as two experiments. In experiment I, the eggs were artificially incubated for 40 days. In experiment II, juveniles were cultured to determine effects of O. onites oil on juveniles for 30 days. The experimental groups were as follows: formalin (3500 ppm for 15 min), O. onites oil (300 ppm for 15 min, 700 ppm for 2 min and 1000 ppm as a dip treatment 15 split‐second) and a control (no treatment). In the experiment I, the highest hatching rate (86%) and survival rate of stage II juveniles (80%) were observed in 1000 ppm dip group. These results were similar to that of formalin group (85% and 79%) respectively. The control group exhibited the lowest hatching rate (49%) and stage II rate (42%) compared with the 1000 ppm dip group and 3500 ppm formalin treatments. However, other concentrations (300 and 700 ppm) of O. onites showed toxic effects on the eggs and there was no hatching. In the experiment II, the survival rate and growth performance of the crayfish juveniles were similar in all groups. This study indicated that the 1000 ppm O. onites dip treatment could be a good alternative to formalin for improved egg hatchability in the artificial incubation of crayfish eggs.  相似文献   

15.
The aim of this study was to evaluate different replacement levels of fishmeal (FM) by feather meal (FeM) on survival and growth of juvenile crayfish (Pacifastacus leniusculus). An 80‐day experiment was conducted with stage 2 juveniles from the onset of exogenous feeding. Four practical diets (500 g kg?1 protein) differing in the level of replacement of FM protein by FeM protein were prepared: 0% (control diet), 15% (8.2% dietary FeM), 25% (13.7% dietary FeM) or 35% (19.2% dietary FeM). Each diet was tested on grouped or individually isolated crayfish. Crayfish fed the control diet or 15% replacement achieved the highest survival (average of grouped and isolated: 88.2%) and growth (grouped and isolated: 13.58 mm carapace length, 523.2 mg weight) and the lowest feed conversion ratio (average of grouped and isolated: 1.11). Final growth of isolated crayfish was significantly higher than that of grouped crayfish for all diets. This study provides the first data on the substitution possibilities of FM by FeM in diets for freshwater crayfish. An 8.2% of FeM (15% replacement of FM protein) can be included in extruded diets for juvenile P. leniusculus during the first 80 days of intensive rearing without impairing growth or feed conversion.  相似文献   

16.
The aim of this study was to evaluate the effects of practical diets with different levels of vitamin A on survival and growth of juvenile crayfish (Pacifastacus leniusculus). An 80‐day trial was conducted with stage 2 juveniles from the onset of exogenous feeding. Four diets differing in the level of retinyl acetate were tested: 0, 0.0025, 0.0050 or 0.0100 g kg?1 diet, equivalent to 0, 2500, 5000 or 10 000 IU vitamin A kg?1 diet, respectively. Each diet was tested on grouped or individually isolated crayfish. Crayfish fed the diet with 5000 or 10 000 IU vitamin A kg?1 diet achieved the highest survival (average of grouped and isolated: 88.9%) and growth (grouped and isolated: 13.45 mm carapace length, 533.4 mg weight). Final growth of isolated crayfish was significantly higher than that of grouped crayfish for all diets. This study provides the first data on vitamin A requirements of freshwater crayfish. A level of 5000 IU vitamin A kg?1 can be recommended for juvenile P. leniusculus during the first period of intensive rearing.  相似文献   

17.
The influence of dietary lipid level was evaluated on growth, survival, and molting of yearling narrow clawed crayfish, Astacus leptodactylus. Yearling crayfish were fed five isonitrogenous diets (35% protein), formulated to contain 4%, 7%, 10%, 13%, or 16% lipid. Crayfish (10.1 ± 1.6 g) were reared for 56 days in 60-L fiberglass tanks at 23 ± 1.7 °C, with flow-through water and continuous aeration. At the end of the trial, crayfish fed 13% lipid had the highest weight gain and specific growth rate, significantly different from crayfish fed 4% and 7% lipid (p < 0.05). Crayfish fed 13% lipid had a significantly higher survival rate (86.7%) than the animals fed 4% lipid (71%) (p < 0.05). Molting was not affected by lipid level (p > 0.05). We recommend 13% dietary lipid level for optimum growth and survival of Astacus leptodactylus in intensive cultivation.  相似文献   

18.
Seahorse aquaculture has been a focus for meeting the demand of traditional medicine and aquarium. Feeble (poor quality) juveniles are commonly found in the commercial seahorse culture. In this study, we compared the growth and survival performances of the feeble and healthy common seahorses Hippocampus kuda. The results show that the feeble juveniles had high growth and survival at the temperature of 27–29 C and salinity of 26–28‰ with frequent feeding (≥three times a day) during first 5 wk. Through a 12‐wk investigation, we found that the air‐bubble disease could significantly affect the specific growth rate and survival of the feeble juveniles. There was a positive and significant correlation between the substrate‐attachment rate and survival rate in the feeble juveniles, and substrate‐attachment rate may be used to assess the quality of the feeble populations in the seahorse H. kuda.  相似文献   

19.
红螯螯虾的室内人工育苗   总被引:8,自引:1,他引:7  
顾志敏 《水产学报》2003,27(1):32-37
于1996-1998年,在浙北地区,对澳大利亚引进的红螯螯是进行亲虾培育、人工越冬,怀卵孵化,室内人工育苗技术的研究。研究表明,在浙北地区,2.8-4.9g的幼虾经5个月左右的饲养可以达到性成熟并部分怀卵,利用电厂余热水水泥池人工越冬的成活率可达70%以上。越冬后亲是在水温20℃以上即开始交配怀卵,怀卵盛期4-6月。红螯螯虾一年可产卵4次,但只有第一、二次怀卵可用于育苗生产,个体一次怀卵量较少,一般为400-500粒,但群体怀卵比率较高。试验还表明,红螯螯虾出膜幼体即呈幼虾状,需依附母体7-10d后才营独立生活并开口摄食外源性饵料,所研制的幼虾Ⅰ号饲料为红螯螯虾室内人工育苗较好的开口饲料。室内人工育苗成活率可达60%以上。  相似文献   

20.
Growth, mortality, moulting rate and cheliped loss were examined in aquaculture experiments with noble crayfish, Astacus astacus L., juveniles from four different Norwegian populations in the period September 1987-June 1988. The juveniles were hatched indoors in May 1987 from parents wild-caught in 1986. The experiments were performed at 18-19°C in communal rearing units. Mean total length at experiment start was about 20mm in all groups. There were no significant differences in mean size (final mean total length: 32-2-34-8mm). mortality (83a-900%) or cheliped loss (429-700%) among juveniles from the different populations when exposed to similar conditions (food: dry pellets; photoperiod: L:D = 8:16). Among crayfish fed fish and potatoes in addition to dry pellets, and with continuous light conditions, mortality was reduced significantly to about 70%. Continuous light conditions significantly increased mean size (final mean length: 36-1-389mm). Moulting occurred from November throughout the experiment period. Moulting rate was positively correlated to mortality and growth rate (i.e. mean length increase). A positive correlation between mortality and cheliped loss, along with direct observations of cannibalism, indicated that agonistic behaviour and cannibalism were the dominating mortality factors. It is suggested that continuous light conditions reduce agonistic behaviour and thereby decrease mortality.  相似文献   

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