首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 771 毫秒
1.
讨论了网箱养殖、工厂化养殖和野生褐牙鲆的外观差异,对比分析了不同生长环境下褐牙鲆的肌肉营养成分和营养学价值。结果显示:网箱养殖的褐牙鲆体形、体色更接近野生褐牙鲆,即有眼侧呈深褐色,无眼侧呈白色;工厂化养殖褐牙鲆有眼侧体色较暗,无眼侧有黑斑。网箱养殖褐牙鲆脂肪含量(2.5%)远低于工厂化养殖的褐牙鲆(4.2%),而接近于野生的褐牙鲆(1.4%);网箱养殖褐牙鲆水分含量比工厂化养殖的高,也更接近野生的褐牙鲆。3种生长环境的褐牙鲆,氨基酸组成是一致的,而且各项比值也都符合FAO/WHO的标准。对比分析必需氨基酸指数(EAAI)和EPA+DPA、SFA、MUFA、PUFA等指标,网箱养殖褐牙鲆均要高于工厂化养殖褐牙鲆,接近而又优于野生的褐牙鲆。在矿物质含量方面,3种生长环境下的褐牙鲆差异不明显。综合各项指标分析,在褐牙鲆的3种生长环境中,网箱养殖的褐牙鲆要优于工厂化养殖的褐牙鲆,而更接近于野生的褐牙鲆。  相似文献   

2.
牙鲆是荣成市工厂化养殖的重要鱼类品种。邱家渔业公司在多年牙鲆养殖的基础上,总结出了一套有益的经验,他们从3厘米~5厘米大小的牙鲆鱼苗养成至20厘米以上的牙鲆鱼,只用7个月的时间,并且鱼的养殖成活率达60%,基本上达到了国内较先进水平。现将他们的主要做法介绍如下:  相似文献   

3.
台湾海峡牙鲆养殖技术研究   总被引:3,自引:0,他引:3  
报道了台湾海峡牙鲆(Paralichthysolivaceus)的养殖技术。经过在室内水泥池189d的饲养,共获得平均全长32.20cm,平均体质量402.10g规格的牙鲆11.5万尾,养殖成活率达96%。养殖结果表明,台湾海峡牙鲆的生长速度快于黄、渤海牙鲆;水温与牙鲆的生长关系密切,台湾海峡牙鲆适宜的温度范围为18~27℃左右;饲料中添加适量中草药对提高牙鲆的成活率有较明显作用。  相似文献   

4.
漠斑牙鲆生物学及其养殖研究进展   总被引:9,自引:0,他引:9  
漠斑牙鲆原产于美国沿海,美国自90年代初开始研究漠斑牙鲆的繁育及其养殖技术。近年来,我国从美国引进漠斑牙鲆进行培育。本文对国内外漠斑牙鲆生物学及其养殖的研究进行了总结,提出了漠斑牙鲆今后研究的方向。  相似文献   

5.
牙鲆网箱养殖试验   总被引:5,自引:0,他引:5  
牙鲆的养殖在日本已有成功的经验。1978~1980年,日本曾大力发展海上牙鲆网箱养殖。虽然后来因夏季高温以及擦伤造成死亡较多,发展受到一些限制。但因它仍有有利的方面,在条件适宜的海域仍是值得使用的一种养殖方式。牙鲆是适合于我国北方海域养殖的种类,为弄清楚山东省沿海地区发展牙鲆网箱养殖的可行性和经济效益,我们在荣成市寻山艾伦湾进行了网箱养殖试验。由于国内市场没有牙鲆鱼种供应,在自然海域也捕不到足够数量鱼种供养成使用,我们的养殖试验从育苗开始,2a内完成一个养殖周期,实际养殖时间为17个月。早期育苗…  相似文献   

6.
郑盛华  邱海源  王宪 《台湾海峡》2005,24(4):540-545
不同换水量、吸污后水中的溶解氧变化对工厂化养殖的成活率具有相当重要影响.本文对牙鲆工厂化养殖进行现场跟踪监测,在养殖水体换水率5~6倍/d,吸污次数在2次/d,养殖水体中溶解氧变化均在牙鲆生长正常范围内,其成活率高达80%以上,成功调控养殖水质,极大降低了工厂化养殖牙鲆的生产成本.  相似文献   

7.
福建沿海牙鲆池塘养殖试验   总被引:3,自引:0,他引:3  
牙鲆 (ParalichthysolivaceusT.&S.)属鲽形目 ,鲆科 ,牙鲆属。南方俗称左口鱼、皇帝鱼、比目鱼 ,其肉质鲜美 ,营养丰富 ,为大型名贵海产鱼类 ,经济价值很高 ,是我国主要养殖品种之一。近几年牙鲆养殖在福建方兴未艾 ,但还存在许多问题 ,如夏季水温过高难以度夏 ,而利用地下水进行工厂化养殖投资大、成本高 ,经济效益不理想。因此 ,作者于1998年利用深水沙质底池塘进行牙鲆养殖试验 ,成功解决度夏问题 ,取得了满意结果。1材料与方法1.1池塘条件选择福建省莆田县南日岛垦区内池塘一个 ,面积6.7ha ,南北…  相似文献   

8.
鲈鱼的人工催产   总被引:3,自引:0,他引:3  
日本近些年在鲈鱼(Lateolabrax japonicus)人工育苗方面的工作成绩较为突出,已能够利用野生亲鱼和人工养殖亲鱼进行规模性育苗生产和全人工养殖。我国有关鲈鱼繁殖的基础研究工作较多,如孙帼英等1994年报道的对鲈鱼繁殖生物学的研究,详细地描述了鲈鱼卵巢的发育分期以及产卵类型和产卵期等,万瑞景1988年和毕庶万等人[1]的调查研究均对鲈鱼的性成熟年龄和产卵习性进行了描述。但鲈鱼人工育苗技术尚未成熟,有关规模性人工育苗的文献报道还很少看到。作者认为目前鲈鱼人工育苗的关键还在于优良亲本的获…  相似文献   

9.
作者综述近年来国内外在褐牙鲆受精卵及仔稚鱼的发育、行为及理化环境对其生理生态的影响等方面的研究进展。着重介绍在人工养殖环境中,水温、盐度、水质、光照等环境因素的变化对褐牙鲆卵的孵化及仔稚鱼的发育和行为所产生的影响,以及褐牙鲆仔稚鱼不同发育阶段对各种理化环境的耐受范围和阈值。探讨人工种苗和天然种苗在形态发育及行为等方面的差异,对今后褐牙鲆的集约化健康养殖提出了几点建议。  相似文献   

10.
报道了墨西哥湾扇贝在广东省南澳试养的过程和结果,试验证明该贝能够在汕头市进行人工养殖,成活率达92.9%,每公顷产量23368.5kg。  相似文献   

11.
鳚亚目 4 科 33 属 95 种,鰕虎鱼亚目 5 科 98 属 259 种,刺尾鱼亚目 5 科 11 属 65 种,鲈形目 19亚目 104 科 535 属 1799 种。  相似文献   

12.
Soil-sized particulates have been collected on board ship by a mesh technique from the lower troposphere of the North, Equatorial and South Atlantic Ocean, northern and southern Indian Ocean, South and East China Sea and various coastal localities.Spectrographic analysis reveals that, on average, the particulates have concentrations of Mn, Ni, Co, Ga, Cr, V, Ba, and Sr which are of the same order of magnitude as those in average crustal material. In contrast, the average concentrations of Pb, Sn, and Zn are one order of magnitude higher than those in average crustal material.Within this “world-wide” average there are significant geographical variations in the distributions of Pb, Sn, and Zn which may be related to anthropogenic sources.On the basis of trace-element distributions lower tropospheric soil-sized marine particulates have been divided into four genetic components; local, zonal, inter-zonal, and global. The proportions of these components vary geographically, and each component may have both a natural and an anthropogenic fraction.  相似文献   

13.
14.
15.
16.
Tautog, Tautoga onitis, is an abundant species of fish in estuaries of the northeastern United States. Planktonic tautog larvae are abundant in summer in these estuaries, but there is little information on rates of growth of tautog larvae feeding on natural assemblages of food in the plankton. We examined abundance and growth of larval tautog and environmental factors during weekly sampling at three sites along a nearshore‐to‐offshore transect in Buzzards Bay, Massachusetts, USA during summer 1994. This is the first study of a robust sample size (336 larvae) to estimate growth rates of field‐caught planktonic tautog larvae feeding on natural diets, using the otolith daily‐growth‐increment method. The study was over the entire summer period when tautog larvae were in the plankton. The sampling sites contrasted in several environmental variables including temperature, dissolved oxygen (DO), and chlorophyll a concentration. There was a temporal progression in the abundance of tautog larvae over the summer, in relation to location and temperature. Tautog larvae were first present nearshore, with a pronounced peak in abundance occurring at the nearshore sites during the last 2 weeks in June. Larvae were absent at this time further offshore. From late June through August, larval abundance progressively decreased nearshore, but increased offshore although never approaching the abundance levels observed at the nearshore sites. The distribution and abundance of tautog larvae appeared to be related to a nearshore‐to‐offshore seasonal warming trend and a nearshore decrease in DO. Otoliths from 336 larvae ranging from 2.3 to 7.7 mm standard length had otolith increment counts ranging from 0 to 19 increments. Growth of larval tautog was estimated at 0.23 mm·day?1, and length of larvae prior to first increment formation was estimated at 2.8 mm indicating that first increment formation occurs 3–4 days after hatching at 2.2 mm. Despite spatial and temporal differences in environmental factors, there were no significant differences in growth rates at any of three given sites over time, or between sites. Because larval presence only occurred at a narrow range of temperature (17–23.5 °C) and DO (6.5–9.3 mg·l?1), in situ differences in growth did not appear to be because of differences in larval distribution and abundance patterns relative to these parameters.  相似文献   

17.
Results of trace-metal analyses of water samples obtained during a cruise with the Soviet R.V. “Akademik Kurchatov” in the Indian Ocean are presented. The determinations were performed on board with atomic absorption spectrophotometry after a two-stage dithiocarbamate—Freon extraction procedure. Trace-metal concentrations found are in the same range as those found recently for similar open-ocean areas by other workers. The values for lead and zinc are probably high due to contamination. Vertical profiles indicate biogenic processes as controlling factors for the increase of cadmium, copper and nickel concentrations with depth. Iron shows an irregular depth distribution as a result of large random variations in concentration.  相似文献   

18.
In June 1981, dissolved Zn, Cd, Cu, Ni, Co, Fe, and Mn were determined from two detailed profiles in anoxic Baltic waters (with extra data for Fe and Mn from August 1979). Dramatic changes across the O2H2S interface occur in the abundances of Cu, Co, Fe, and Mn (by factors of ?100). The concentrations of Zn, Cd, and Ni at the redox front decrease by factors between 3 to 5.Equilibrium calculations are presented for varying concentrations of hydrogen sulfide and compared with the field data. The study strongly supports the assumption that the solubility of Zn, Cd, Cu, and Ni is greatly enhanced and controlled by the formation of bisulfide and(or) polysulfide complexes. Differences between predicted and measured concentrations of these elements are mainly evident at lower ΣH2S concentrations.Cobalt proved to be very mobile in anoxic regions, and the results indicate that the concentrations are limited by CoS precipitation. The iron (Fe2+) and manganese (Mn2+) distribution in sulfide-containing waters is controlled by total flux from sediment-water interfaces rather than by equilibrium concentrations of their solid phases (FeS and MnCO3). The concentrations of these metals are therefore expected to increase with prolonged stagnation periods in the basin.  相似文献   

19.
Concentrations of dissolved nutrients (NO3, PO4, Si), germanium species, arsenic species, tin, barium, dimethylsulfide and related parameters were measured along the salinity gradient in Charlotte Harbor. Phosphate enrichment from the phosphate industry on the Peace River promotes a productive diatom bloom near the river mouth where NO3 and Si are completely consumed. Inorganic germanium is completely depleted in this bloom by uptake into biogenic opal. The GeSi ratio taken up by diatoms is about 0·7 × 10?6, the same as that provided by the river flux, confirming that siliceous organisms incorporate germanium as an accidental trace replacement for silica. Monomethylgermanium and dimethylgermanium concentrations are undetectable in the Peace River, and increase linearly with increasing salinity to the seawater end of the bay, suggesting that these organogermanium species behave conservatively in estuaries, and are neither produced nor consumed during estuarine biogenic opal formation or dissolution. Inorganic arsenic displays slight removal in the bloom. Monomethylarsenic is produced both in the bloom and in mid-estuary, while dimethylarsenic is conservative in the bloom but produced in mid-estuary. The total production of methylarsenicals within the bay approximately balances the removal of inorganic arsenic, suggesting that most biological arsenic uptake in the estuary is biomethylated and released to the water column. Dimethylsulfide increases with increasing salinity in the estuary and shows evidence of removal, probably both by degassing and by microbial consumption. An input of DMS is observed in the central estuary. The behavior of total dissolvable tin shows no biological activity in the bloom or in mid-estuary, but does display a low-salinity input signal that parallels dissolved organic material, perhaps suggesting an association between tin and DOM. Barium displays dramatic input behavior at mid-salinities, probably due to slow release from clays deposited in the harbor after catastrophic phosphate slime spills into the Peace River.  相似文献   

20.
海洋环境及沉积地球化学的调查研究,常需同时了解多种元素在海洋底质中的含量及其分布规律.对于某些非金属及半金属元素,我们曾研究过应用碱性有机染料的萃取-光度测定法[1-3].原子吸收分光光度法则可以快速、准确地测定海洋沉积物中的许多种金属的含量[4-6],一般不需要大量的预处理.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号