美国路易斯安那州的克氏原螯虾产业发展概述

阐述了美国路易斯安那州的克氏原螯虾产业的概况,包括路易斯安那州的螯虾养殖业发展简史、螯虾历年的渔获状况、近十年来的螯虾批发价格统计及典型的养殖模式等,为国内克氏原螯虾业发展提供借鉴。     

多重周期饥饿后克氏原螯虾的补偿生长及生理指标变化

[目的]探讨克氏原螯虾的生理指标与其饥饿补偿生长的相关关系。[方法]通过分组饲养试验研究了不同周期性饥饿对试验螯虾生长和生理指标的影响。[结果]72d后,SR22、SR44和SR66组的螯虾体重极显著高于对照组,SR11组的螯虾体重和对照组无显著差异;各处理组螯虾的单周期特殊生长率均高于对照组。SR11、SR22和SR44组螯虾SOD活性和存活率与对照组无显著差异。随着饥饿时间的增加,螯虾的消化酶活性、含肉率和肌糖原含量在SR00、SR11、SR22和SR44组极显著上升,在SR66、SR88、SR1212和SR1818组极显著下降;其肝糖原含量和肝体比在SR00、SR11、SR22和SR44组呈上升趋势。SR66和SR88组螯虾的消化酶活性极显著高于对照组。SR44组的肠胃淀粉酶和蛋白酶活性最高。螯虾的肝体比、肌糖原含量、肝糖原含量均在SR44组达到极大值,在SR1818组达到极小值。[结论]该研究为提高克氏原螯虾的养殖收益奠定了理论基础。     

Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non‐target crayfish (Procambarus clarkii) associated with rice–crayfish crop rotations

BACKGROUND: Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non‐target crayfish associated with rice–crayfish crop rotations. One solution to the near‐exclusive reliance on pyrethroids in a rice–crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice–crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda‐cyhalothrin and etofenprox. RESULTS: Neonicotinoid insecticides are at least 2–3 orders of magnitude less acutely toxic (96 h LC₅₀) than pyrethroids to juvenile Procambarid crayfish: lambda‐cyhalothrin (0.16 µg AI L^?1) = etofenprox (0.29 µg AI L^?1) ? clothianidin (59 µg AI L^?1) > thiamethoxam (967 µg AI L^?1) > dinotefuran (2032 µg AI L^?1). CONCLUSION: Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice–crayfish crop rotations. Further field‐level neonicotinoid acute and chronic toxicity testing with crayfish is needed. Copyright © 2009 Society of Chemical Industry     

晚稻-虾-鳅耦合养殖技术研究

在面积4 hm~2的稻田中进行了晚稻-虾-鳅耦合养殖试验,利用冬闲稻田除野期间向稻田中移植水草,并根据克氏原螯虾和泥鳅的上市规格、生长周期、生活习性等特点,采用不同设备进行克氏原螯虾和泥鳅的捕捞与分离。结果表明,共收获晚稻30 210 kg、克氏原螯虾5 516 kg、泥鳅1 860 kg,平均渔获量1 844 kg/hm~2,平均利润40 852元/hm~2。     

稻田养殖克氏原螯虾重金属监测分析

[目的]了解扬州地区稻田养殖克氏原螯虾的重金属污染情况。[方法]采集了扬州市3个区套养克氏原螯虾稻田的水质、底泥和克氏原螯虾样本,并对其进行了重金属砷、镉和汞的检测和分析。[结果]检测显示,所有监测稻田的水质和底泥的重金属砷、镉和汞的检测值都符合无公害水产品养殖环境要求,环境无明显重金属污染;克氏原螯虾的重金属砷、镉和汞的检测值未超过无公害水产品质量安全要求,也未超过我国水产品规定的最大残留标准,且平均检测值都相对较低,对人的健康风险较小。[结论]研究可为稻田养殖克氏原螯虾的健康发展及质量保证提供参考。     

一株克氏原螯虾雷氏普罗威登斯菌的分离鉴定与联合药敏试验

为了探明克氏原螯虾(Procambarus clarkii)5—6月死亡的病因并制定相应的治疗方案,本试验从患病克氏原螯虾肝胰腺中分离到1株病原菌(L20190509),通过生理生化特征、16S rRNA序列分析和进化树进行鉴定,通过琼脂扩散法测定了该菌株的药物敏感性,进一步研究了抗菌药物与天然化合物的联合抑菌作用.结...     

克氏原螯虾不同发育阶段卵巢中EST同工酶比较

[目的]研究克氏原螯虾(Procambarus clarkii)卵巢成熟过程EST的变化。[方法]采用聚丙烯酰胺凝胶电泳方法,分析了卵黄形成期和成熟期卵巢中酯酶同工酶(EST)的表达情况。[结果]所研究的两个阶段卵巢中EST同工酶的表达可分为Ⅰ、Ⅱ、Ⅲ共3个区。其中Ⅰ区和Ⅱ区卵黄形成期EST表达较强,酶带明显比成熟期浓,尤其是Ⅰ区,卵黄形成期EST同工酶的表达最强。相反,在Ⅲ区,成熟期EST酶带明显比卵黄形成区浓。[结论]在克氏原螯虾卵子成熟过程中,EST基因的表达存在时间差异性。     

克氏原螯虾染色体及其核型

染色体是遗传物质的载体,是研究细胞遗传学的基础,为研究克氏原螯虾染色体及其核型,实验以性未成熟雄性个体的精巢为材料,采用低渗和空气干燥常规方法制备细胞分裂中期染色体标本,研究了克氏原螯虾染色体及核型。Giemsa和DAPI染色后在显微镜下观察到清晰的精母细胞减数分裂中期二价体和精原细胞有丝分裂中期染色体时相。对减数分裂中期二价体及有丝分裂中期染色体进行了数目上的统计。结果显示,克氏原螯虾二倍与单倍染色体数目分别为2N=188和N=94。由于有丝分裂染色体形状微小,核型分析困难,故选取减数分裂中期二价体,根据长度及着丝点位置对其进行了初步核型分析,核型公式为N=55M+22(SM,ST)+17T,未发现异形性染色体。     

Reproduction efficiency of the crayfish Procambarus acanthophorus in relation to size and diet

Reproductive efficiency of the largest individuals and a random group of broodstock of crayfish Procambarus acanthophorus was measured using two commercial shrimp feeds, Feed 1 (F1) broodstocks (40%/9% protein/lipids) and Feed 2 (F2) growth-out (35%/7% protein/lipids). An experimental design of four treatments with two replicates was used. Females were labeled with elastomers to determine the time between spawning and number of offspring per treatment. The number of ovigerous females in the largest individuals fed F2 (58) was significantly higher than ovigerous females in the control group fed F1 (30).The number of young crayfish per female produced in the largest individuals (173 ± 71.6) treatment was significantly higher than the crayfish produced in the control group (86.6 ± 42.6). The average interval between spawns, regardless of diet, in the largest females was 2.9 months and 2.6 months in control group females.     

日本沼虾和克氏原螯虾胃容量的研究

以体重0.672～4.827g的日本沼虾(Macrobrachium nipponense)和3.678～43.163g的克氏原螯虾(Procambarus clarkii)为试验对象,研究这两种虾的胃容量及其与体长、体重间的关系。结果表明,日本沼虾和克氏原螯虾胃容量随着体重和体长的增加而增加;将日本沼虾、雄性克氏原螯虾和雌性克氏原螯虾的胃容量(y)和体重(x)进行回归分析,分别得方程式:y=0.021 5x+0.006 5(r2=0.948 5),y=0.044 7x-0.008 5(r2=0.964 8),y=0.043 6x+0.0519(r2=0.978 7);3.009～4.827 g的日本沼虾比胃容量显著小于0.672～2.811g的个体,12.967～42.071g的雄性克氏原螯虾比胃容量显著小于3.678～9.754 g的个体,不同规格的雌性克氏原螯虾比胃容量差异不显著。