不同品系中华绒螯蟹土池生态育苗效果比较     

殷乐  姜晓东  王海宁  陈瑜  吴旭干 《水产科技情报》2022,49(4):193-199

为评估不同品系中华绒螯蟹（Eriocheir sinensis）的繁殖性能和育苗效果,分别采用中华绒螯蟹二龄早熟品系（雌体≥150 g,雄体≥210 g）、“长荡湖1号”A系（雌体≥200 g,雄体≥310 g）、“长荡湖1号”B系（雌体≥250 g,雄体≥360 g）及超大规格品系（雌体≥300 g,雄体≥400 g）作为亲本进行土池生态育苗试验,比较了各品系的抱卵蟹获得率、亲本孵化率、育苗期间的投饵量、幼体变态速度以及大眼幼体产量等指标。试验结果显示：（1）各品系越冬后的抱卵蟹获得率随着亲本规格的增大而明显降低,抱卵蟹成功孵化率随着亲本规格的增大同样呈降低趋势,但组间差异不明显（P>0.05）。（2）各品系投饵量在幼体培育期间呈现先增后减的变化趋势,其中,溞Ⅴ期最高,日投饵量约为75 g/m²;与之相反,幼体蜕皮周期在幼体培育过程中呈现出先降后增的变化趋势,溞Ⅲ-Ⅳ期蜕皮周期最短,仅为5～6 d。（3）除了个别产量异常的池塘外,各品系单蟹产苗量及饵料系数均随着亲本规格的增大而提高,且各品系大眼幼体淡化率差异较小,均在90%左右。结果表明,虽然大规格品系在...  相似文献   

不同氮磷钾配比缓释肥对华北落叶松容器苗生长的影响     

奚旺  刘勇  马履一  李国雷  贾忠奎  蒋乐  陈闯  史文辉 《中南林业科技大学学报(自然科学版)》2014,(5):26-30

以华北落叶松播种容器苗为研究对象,在总施氮量相同的条件下,设4个施肥配比处理,通过比较苗木形态指标及矿质元素含量的差异,研究不同施肥方式、施肥配比对华北落叶松容器苗生长的影响。结果表明:苗木生物量及氮含量随着磷、钾肥比例的增加而呈增加趋势;缓释肥氮磷钾配比为13∶13∶13、释放期为150~180 d、施氮量为100 mg/株为华北落叶松当年生容器苗最佳施肥处理,此处理下苗木生物量和氮含量达到最大,分别为0.54 g/株、13.79 mg/株,平均苗高为13.0 cm、地径为2.7 mm,较国家行业标准LY1000-91中规定的1年生华北落叶松容器苗的苗高、地径分别增加30.3%、33%,苗木合格率为9 5%,比国标规定的要求增加5%。  相似文献   

西藏小麦品种籽粒硬度遗传多样性     

李善富  李建民  王雪玲  魏乐  李红琴  刘宝龙  张怀刚 《西北农业学报》2014,23(8):40-44

籽粒硬度是影响小麦磨粉品质和食品品质的重要因素。利用单粒谷物特性测定仪、PCR扩增和核苷酸测序技术,对121份西藏地方品种进行籽粒硬度性状遗传多样性研究。结果表明:西藏品种籽粒硬度平均值为43.73%,硬度值大于60%的品种有43种,占35.5%;混合麦22个,占18.2%;软质麦56个,比例为46.3%。符合优质饼干硬度特性的品种有42种,达到34.7%。有5种硬度基因组合类型:野生型、PinaD1b、Pinb-D1b、Pinb-D1c、Pinb-D1p。野生型比例最高,占51.22%。Pinb-D1c次之,占21.31%,其余依次为Pinb-D1b、Pina-D1b、Pinb-D1p。各种组合类型的SKCS硬度值Pinb-D1cPina-D1bPinb-D1bPinb-D1p野生型。西藏小麦品种籽粒硬度性状遗传多样性的研究将为青藏高原以及其他地区的育种提供种质资源和理论依据。  相似文献   

Seasonal changes in circulating growth hormone (GH), hepatic GH-binding and plasma insulin-like growth factor-I immunoreactivity in a marine fish,gilthead sea bream,Sparus aurata     

J. Pérez-Sánchez  H. Marti-Palanca  P-Y. Le Bail 《Fish physiology and biochemistry》1994,13(3):199-208

We have studied the seasonal relationship between growth and circulating growth hormone (GH), hepatic GH-binding and plasma insulin-like growth factor-I immunoreactivity in gilthead sea bream,Sparus aurata. The seasonal increase in plasma GH levels preceded by several weeks the summer increase in growth rates. In contrast, a marked increase in hepatic GH-binding with a high degree of endogenous GH occupancy was found during the period of maximum growth which suggests an enhanced sensitivity of liver to GH action. Thus, circulating levels of immunoreactive IGF-I, probably derived from the liver in response to GH action, were positively correlated with growth throughout the experimental period although a consistent relationship between growth and circulating GH was not found. In spite of this, we consider that, in gilthead sea bream, as in several other teleosts, the availability of endogenous GH can limit growth. Thus, under environmental conditions of suboptimal growth, a single intraperitoneal injection of recombinant rainbow trout GH (rtGH) induced over the dose range tested (0.75, 1.5, 3 μg g BW⁻¹) an increase in plasma IGF-I-like immunoreactivity comparable to that seen during the period of maximum growth.  相似文献   

The Potential for Replacement of Live Feeds in Larval Culture   总被引：6，自引：0，他引：6  

David A.  Jones  Mohd. Salleh  Kamarudin Lewis Le  Vay 《Journal of the World Aquaculture Society》1993,24(2):199-210

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Differential distribution and response to experimental sexual maturation of two forms of brain gonadotropin-releasing hormone (GnRH) in the European eel,Anguilla anguilla     

Sylvie Dufour  Maïté Montero  Nadine Le Belle  Marc Bassompierre  Judy A. King  Robert P. Millar  Richard E. Peter  Yves-Alain Fontaine 《Fish physiology and biochemistry》1993,11(1-6):99-106

Using specific radioimmunoassays for the two GnRH molecular forms present in the European eel, Anguilla anguilla, (mGnRH and cGnRH II), we compared their distributions in the pituitary and different parts of the brain of female silver eels, as well as the modifications of their levels in experimentally matured female eels (treated with carp pituitary extract). In control eels, mGnRH levels were higher than cGnRH II levels in the pituitary, olfactory lobes and telencephalon, di- and mesencephalon, while the opposite was found in the posterior part of the brain (met- and myelencephalon). Experimental sexual maturation of the gonads significantly increased mGnRH levels in the pituitary and anterior parts of the brain; such a positive effect was not observed on the low cGnRH II levels, which were, in contrast, reduced. These data indicate that the positive feedback of gonadal hormones on GnRH, that we previously demonstrated, would specifically affect the mGnRH form. The differential distribution and control of mGnRH and cGnRH II suggest that these two forms have different physiological roles in the eel. The large increase in mGnRH during sexual maturation suggests the prime implication of this form in the neuroendocrine control of reproduction.  相似文献   

我国远洋渔业的发展浅析     

吕祥  李璐  骆乐 《渔业经济研究》2007,(3):20-22

我国远洋渔业自新中国成立后有了长足发展，但是，仍然面临着严重的问题。尤其是《国际海洋法》生效后，我国远洋渔业的发展环境将更加严峻。因此，政府应该通过加大投资力度、开展渔业外交、寻找新的合作伙伴等措施来积极推动远洋渔业的发展。  相似文献   

Development of nursery culture techniques for the mud crab Scylla paramamosain (Estampador)     

Vu Ngoc Ut  Lewis Le Vay  Truong Trong Nghia  & Tran Thi Hong Hanh 《Aquaculture Research》2007,38(14):1563-1568

Cannibalism is one of the main causes of mortality in the culture of the mud crab Scylla paramamosain, particularly in the early post‐larval and juvenile stages when the densities of hatchery‐reared crabs may be very high before stocking into ponds or release into the wild for stock enhancement. In a series of experiments investigating cannibalism mitigation, the influence of stocking density, the effectiveness of sand substrate, brick and shell shelters and feed type were compared in culture of crabs from instar 1 for short nursery periods of 15–30 days. Inclusion of brick and shell shelters significantly increased survival over sand substrate alone. However, inclusion of shelters did not affect growth rates. In scaled‐up nursery production in lined‐ponds, with shelters, live Artemia biomass and fresh chopped shrimp or tilapia were found to be equally effective feeds for juvenile crabs stocked at a density of 70 m⁻² from instar 1 and grown for 30 days [52–66% survival, 21.6–24.6 mm carapace width (CW)]. In an extended nursery period for a further 30 days, crabs of 22 mm CW, stocked at 30 m⁻² in the same ponds, attained a final size of 34.5–36.2 mm CW with a survival of 64.3–67.0% using the same feeds.  相似文献   

Reference intervals and age‐related changes for venous biochemical,hematological, electrolytic,and blood gas variables using a point of care analyzer in 68 puppies     

Mauria A. O'Brien DVM  DACVECC  Maureen A. McMichael DVM  DACVECC  Kevin Le Boedec DVM  MS  George Lees DVM  MS  DACVIM 《Journal of Veterinary Emergency and Critical Care》2014,24(3):291-301

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投喂频率对凡纳滨对虾生长和水质的影响     

叶乐  林黑着  李卓佳  吴开畅  文国樑  马之明  朱昌福 《南方水产》2005,1(4):55-59

研究了不同投喂频率(1,2,3,4和5次·d-1)对凡纳滨对虾生长、存活率和水质的影响。试验在室内2m3的圆形水泥池(d=1.6m)中进行,采用全封闭养殖模式,凡纳滨对虾(初始重量为0.24g)养殖密度为50尾·m-3,投喂人工配合饲料(粗蛋白含量为42.98%)。通过7周的试验,结果表明,投喂频率为1～4次·d-1时,随着投喂频率的增加,对虾增重率显著增加;投喂频率由4次·d-1增加到5次·d-1时,对虾增重率略有增加,但差异不显著。凡纳滨对虾的成活率在1次·d-1时最低,2次·d-1时最高,2～5次·d-1时随着投喂频率的增加而降低(投喂频率为1和2次·d-1之间、3和4次·d-1之间差异显著)。投喂频率为3次·d-1时饲料系数最低,蛋白质效率最高。随着投喂频率1～3次·d-1增加,饲料系数逐渐显著降低,蛋白质效率显著递增;而投喂频率从3～5次·d-1增加时,饲料系数增大,蛋白质效率逐渐下降(3和4次·d-1差异显著;4和5次·d-1之间差异不显著)。投喂频率对水环境中的pH值、H2S含量、COD、盐度等水质指标没有显著影响;在养殖后期水环境中投喂频率3～5次·d-1的NH 4和NO-2浓度较投喂频率1～2次·d-1时高。  相似文献