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1.
为了解黑水河红尾副鳅(Paracobitis variegates)时空分布特征与最适生境,分别于2018年11月、2019年1月、2019年3月、2019年5月和2019年8月调查了黑水河中下游流域23个点位的红尾副鳅资源现状和相关环境因子,使用广义可加模型(GAM)筛选影响资源密度(CPUE)分布的主要环境因子并确定最适条件范围。结果显示,海拔、月份、温度和流速对红尾副鳅的CPUE均有极显著影响,溶解氧对红尾副鳅的CPUE有显著影响,且海拔的偏差解释率最高为33.7%,其次是月份(32.8%),环境因子中溶解氧的偏差解释率最高,为12.5%。黑水河红尾副鳅CPUE具有极显著的时空分布差异,从低海拔到高海拔,黑水河红尾副鳅CPUE的变化具有波动性,但总体呈上升的趋势,在3月和5月,红尾副鳅CPUE较高,在5―10月,CPUE逐渐下降。影响红尾副鳅CPUE分布的主要环境因子为温度、流速和溶解氧。GAM模型中,水温和流速与红尾副鳅CPUE具有极显著的非线性关系,溶解氧与红尾副鳅CPUE具有显著的非线性关系,在11.7～25.9℃,随着水温的上升,红尾副鳅CPUE呈先下降后有短暂上升后又下...  相似文献   

2.
为了探究鱼类感应流速随体长因素的变化,以黄河上游2种裂腹鱼为研究对象,利用环形水槽实验装置,采用递增流速法,测试并分析了不同体长鱼类的感应流速。结果表明,体长(BL, 20.67±3.65) cm的花斑裸鲤(Gymnocypris eckloni)和BL (14.50±2.24) cm的黄河裸裂尻鱼(Schizopygopsis pylzovi)的绝对感应流速分别为(4.97±1.22) cm·s~(-1)和(4.52±0.92) cm·s~(-1),相对感应流速分别为(0.24±0.045) BL·s~(-1)和(0.31±0.052) BL·s~(-1);绝对感应流速与体长呈正相关关系,相对感应流速与体长呈负相关关系,相对感应流速与体长呈现负相关关系是由于绝对感应流速的增加速率小于体长的增加速率;2种裂腹鱼类的绝对感应流速差异不显著(P0.05);构建的绝对感应流速与体长的非线性回归模型能够有效地解释鱼类感应流速对体长的响应。该研究对其他较难捕获测试样本区域的鱼类游泳特性的定性预测研究具有一定指导作用,也可为过鱼设施的设计提供基础数据支撑。  相似文献   

3.
【学名】红尾副鳅（Paracobitis variegatus） 【别名】红尾子、红尾杆鳅、红尾鱼、钢鳅 【原产地】中国。分布于我国四川、重庆境内长江水系的干、支流,还有陕西南部和甘肃的白龙江以及云南江、南盘江水系。 【分类地位】隶属鲤形目（Cyprinformes）鳅科（Cobitidae）条鳅亚科（Nemacheilinae）副鳅属（Paracobitis Bleeker）。  相似文献   

4.
长臀（Cranoglanis bouderius）和白甲鱼（Onychostoma sima）是目前北盘江主要放流鱼类,但这2种鱼的放流效果差异较大。由于鱼类的突进游速在一定程度上影响增殖放流的效果,故试验采用自制测试装置,用递增流速法测试了2种鱼的突进游速。结果显示,白甲鱼的突进游速大于长臀,且2种鱼的突进游速均随体长增加而近似线性增大;而相对突进游速则随着体长的增加而近似线性减小。研究结果可为北盘江鱼类增殖放流和放流效果评估,以及日后北盘江的拦鱼、诱鱼、集鱼船等鱼类资源保护措施的实施提供参考。  相似文献   

5.
为了探究大渡河软刺裸裂尻鱼的游泳能力,为大渡河水域过鱼设施的设计提供基础数据支持以及充实鱼类游泳能力机制的数据资料。本研究采用递增流速法,用自制Brett-type水槽对大渡河软刺裸裂尻鱼的感应流速、临界游泳速度、突进游泳速度进行测试。结果表明,在水温范围为11.9~14.1℃条件下,体长为15~21.5cm,体重为34.8~152.9g的大渡河软刺裸裂尻鱼的绝对感应流速为0.084~0.0948m/s,相对感应流速为0.321~0.588BL/s,相对感应游泳速度随体长增大而减小;绝对临界游泳速度（Ucrit）为0.61~1.31m/s,相对临界游泳速度为4.16~5.076BL/s,这两者均随体长增大而增大;大渡河软刺裸裂尻鱼的绝对突进游泳速度（Uburst）为1.02~1.4m/s,与体长关系并不显著（P>0.05）,相对突进游泳速度为5.73~8.36BL/s,随体长增加而减小。通过视频回放发现,试验鱼突进游泳速度测试过程分为三个阶段：占突进速度0~29%,速度范围为0~0.4m/s;占突进速度29%~60%,速度范围为0.4~0.84m/s;占突进速度60%~100%,速度范围为0.84~1.4m/s。各阶段的静止不动、平稳摆动、冲刺-滑行三种游泳状态所占比例有显著不同。本研究可为以大渡河软刺裸裂尻鱼为过鱼对象的过鱼设施设计提供流速指标参考。  相似文献   

6.
采用自行设计的鱼类游泳能力测试槽,用“流速递增法”测定了鲤（Cyprinus carpio）（体长24.46±5.9cm）、鲫（Carassius auratus）（体长13.66±4.7cm）、鲢（Hypophthalmichthys molitrix）（体长32.73±3.7cm）、鳙（Aristichthys nobilis）（体长30.47±1.7cm）以及蒙古鲌（Culter mongolicus mongolicus）（体长23.51±3.1cm）等五种鱼类的感应流速。结果表明鲤、鲫、鲢、鳙以及蒙古鲌的感应流速分别是（3.55±2.43）、（2.408±2.00）、（4.605±2.575）、（2.033±1.019）和（0.135-3.930）cm?s-1,相对感应流速分别是（0.147±0.097）、（0.182±0.166）、（0.142±0.078）、（0.067±0.034）和（0.08±0.054）BL?s-1; 鱼类的体长与感应流速不存在相关关系;相对感应流速更加准确的表示鱼类的感应流速;不同鱼类之间的感应流速差异极显著（P<0.01）,鱼类的感应流速是进化的结果。  相似文献   

7.
在金沙江下游干流大规模水电开发的背景下,干流开发与支流保护是生态环境保护的有效措施;黑水河是白鹤滩库区鱼类的优先保护支流,确定其鱼类优先保护次序和保护物种是进行鱼类栖息地修复和保护工作的首要任务和前提基础。在野外调查和查阅相关文献资料的基础上,运用濒危系数、遗传价值系数和物种价值系数对黑水河35种鱼类进行优先保护次序的定量分析,并结合黑水河栖息地实际情况,确定保护目标鱼类。结果显示,达到黑水河一级保护的鱼类只有1种,为长江上游特有鱼类长薄鳅（Leptobotia elongata）;达到二级保护的种类有12种,其中昆明裂腹鱼（Schizothorax grahami）、黄石爬鮡（Euchiloglanis kishinouyei）、短须裂腹鱼（Schizothorax wangchiachii）和长鳍吻鮈（Rhinogobio ventralis）为长江上游特有鱼类;处于三级保护的鱼类有17种,其中钝吻棒花鱼（Abbottina obtusirostris）和张氏?（Hemiculter tchangi）是长江上游特有鱼类;四级保护鱼类有5种,其中短体副鳅（Paracobitis potanini）为长江上游特有鱼类,评价结果基本反映了黑水河鱼类的实际情况。结合白鹤滩水库蓄水后黑水河栖息地生境改变的情况,最终确定昆明裂腹鱼、黄石爬鮡、短须裂腹鱼为黑水河栖息地修复和保护的目标鱼类,长薄鳅和长鳍吻鮈为备选保护鱼类。  相似文献   

8.
刘利林  王帅 《中国水产》2011,(11):33-35
叶尔羌高原鳅TriplophysarHedinichthys）yarkandensis（Day）,又名叶尔羌鼓缥鳅、叶尔羌条鳅,地方名狗头鱼。属鲤形目、鳅科、条鳅亚科、高原鳅属、鼓鳔亚属,广泛分布于塔里木河水系,是塔里木河流域中生长较快、个体较大的一种,是生活在塔里木河流域的主要优势土著鱼类之一。叶尔羌高原鳅在鳅科鱼类中属于个体较大的鱼类之一,最大体长可达30．0cm、体重在305g左右。  相似文献   

9.
大宁河红尾副鳅年龄与生长的研究   总被引：2，自引：1，他引：1  
利用耳石、脊椎骨对2006年10月至2007年11月采自大宁河的129尾红尾副鳅(Paracobitis variegates)的年轮特征进行研究,并对生长情况进行分析。结果显示:低龄脊椎骨钙质沉积不明显,轮纹观察不清楚,耳石轮纹较清楚。红尾副鳅群体由2~6龄共5个龄组组成,体重体长关系为W=1.95×10-4L2.309,耳石直径与体长的关系为L=263.24R+9.03,生长方程为Lt=222.708[1-e-0.092(t+2.162)];Wt=51.399[1-e-0.092(t+2.162)]2.309。结果表明:红尾副鳅体重生长拐点年龄为6.97龄,7龄前后为合理的捕捞时期。  相似文献   

10.
为评价红尾副鳅(Paracobitis variegatus)肌肉的营养价值与食用安全性,试验一选取采自石棉县的野生红尾副鳅165尾,其中雄鳅81尾(4.29±0.43)g,雌鳅84尾(4.36±0.59)g,检测了肌肉的一般营养成分、氨基酸组成和部分矿物元素,并将测定结果与泥鳅(Misgurnus anguillicaudatus)相比较,对红尾副鳅肌肉的营养价值进行了评定;试验二选取体表无伤、体质健壮的雨城区红尾副鳅120尾(4.21±0.85)g、天全县红尾副鳅120尾(3.22±0.73)g,分别置于不同浓度铬(0、200、400、600 mg/L)和铜(0、0.3、0.6、0.9 mg/L)的处理液中。分别于10 h、24 h后取肝胰脏和肌肉,检测铬、铜含量,考察红尾副鳅对铬、铜的富集程度。结果表明,红尾副鳅肌肉(鲜样)中水分、粗蛋白、粗脂肪和灰分的质量分数分别为78.69%、18.49%、2.15%和1.34%;肌肉中17种水解氨基酸总量为87.50%(质量分数,干样),其中7种必需氨基酸总量为35.54%,占氨基酸总量的40.62%,必需氨基酸与非必需氨基酸的比值为0.8008,氨基酸评分为1.02,赖氨酸含量丰富,苯丙氨酸为第一限制性氨基酸,必需氨基指数为75.23。红尾副鳅(石棉县)肌肉THQCu、THQCr分别为0.965 8和1.044 4,且Cu、As、Pb、Cr和Cd的THQ总值达2.266 9,表明长期食用野生红尾副鳅(石棉县)存在健康风险。不同浓度Cr、Cu处理组红尾副鳅(雨城区、天全县)肝胰脏和肌肉Cr、Cu含量均明显高于对照组,说明红尾副鳅对Cr、Cu具有较强的富集能力。综上,红尾副鳅是一种营养价值较高的淡水鱼类,具有良好的开发利用前景,但因红尾副鳅对重金属(Cr、Cu)的富集能力较强,进行人工养殖时须严格检测饲料和水体中重金属(Cr、Cu)的含量,并尽可能地缩短养殖周期。  相似文献   

11.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

12.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

13.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

14.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future.  相似文献   

15.
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos.  相似文献   

16.
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
The sea raven, Hemitripterus americanus, is a sit-and-wait, low metabolic rate, marine teleost. The objective of this study was to determine i) whether cortisol implantation (50 mg. kg-1) for 7 days altered hepatocyte metabolism, and hepatocyte responsiveness to epinephrine, glucagon and insulin, and ii) whether 8 weeks of food-deprivation modified the above response. Cortisol implantation significantly increased hepatocyte total glucose production and oxidation from alanine compared to the sham group. There was no cortisol effect on glycogen breakdown, suggesting that the activation of other pathways, including gluconeogenesis, are required to account for the increased glucose production. Epinephrine-mediated (10-5M) glycogen breakdown and insulin-mediated (10-8M) total glucose production were enhanced in hepatocytes of cortisol implanted sea ravens, but there were no change in any glucagon (10-7M) effects. The enhanced glycogen breakdown in the absence of similar increases in total glucose production with epinephrine indicates mobilization of carbohydrate reserves for endogenous use by the liver. Food-deprivation for 8 weeks significantly decreased condition factor, plasma cortisol concentration and liver glycogen content in the sea raven, but had no effect on plasma glucose concentration. Hepatocyte total glucose production and flux rates from alanine increased significantly with food-deprivation. Moreover, food-deprivation increased responsiveness of total hepatocyte glucose production to the actions of glucagon and insulin, but not to epinephrine; none of these effects were modified by cortisol implantation. Our results indicate that cortisol in the sea raven exerts both a direct and an indirect or permissive effect on hepatocyte metabolism by modifying hepatocyte responsiveness to epinephrine and insulin stimulation. Cortisol implantation did not modify the effects of glucagon or food-deprivation in this species.  相似文献   

18.
Important environmental processes for the survival and recruitment of early life stages of pelagic fishes have been synthesized through Bakun's fundamental triad as enrichment, concentration and retention processes (A. Bakun, 1996, Patterns in the Ocean. Ocean Processes and Marine Population Dynamics. San Diego, CA, USA: University of California Sea Grant). This conceptual framework states that from favourable spawning habitats, eggs and larvae would be transported to and/or retained in places where food originating from enrichment areas would be concentrated. We propose a method for quantifying two of the triad processes, enrichment and retention, based on the Lagrangian tracking of particles transported within water velocity fields generated by a three‐dimensional hydrodynamic model. We apply this method to the southern Benguela upwelling ecosystem, constructing putative maps of enrichment and retention. We comment on these maps regarding main features of the circulation in the region, and investigate seasonal variability of the processes. We finally discuss the results in relation to available knowledge on the reproductive strategies of two pelagic clupeoid species abundant in the southern Benguela, anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). Our approach is intended to be sufficiently generic so as to allow its application to other upwelling systems.  相似文献   

19.
This study evaluated the effects of three levels of loading density (200, 300 and 400 g L−1) and four levels of duration (1, 3, 6 and 9 h) on the mortality, plasma cortisol and chloride levels and growth of rohu Labeo rohita fingerlings in a transport simulation. While total immediate mortality was low (4–12%), delayed mortality was high (27–49%). Initial capture and handling were found to constitute the most stressful phase as indicated by elevated plasma cortisol. The levels of cortisol continued to rise at 6 and 9 h after transport, with the highest level observed at 9 h after transport. The level of plasma chloride fell after transport across all density levels and treatment durations. Specific growth rate (SGR, %/day) and total bacterial density (cfu/g) were not different between and within treatments, and between treatments and the controls. This study demonstrates that transport has a profound effect on the stress responses of rohu fingerlings. Although the level of immediate mortality was low, the higher level of delayed mortality has serious implications in terms of production inefficiency for grow-out farmers.  相似文献   

20.
  • 1. The common name ‘tilapia’ refers to a group of tropical freshwater fish in the family Cichlidae (Oreochromis, Tilapia, and Sarotherodon spp.) that are indigenous to Africa and the southwestern Middle East. Since the 1930s, tilapias have been intentionally dispersed worldwide for the biological control of aquatic weeds and insects, as baitfish for certain capture fisheries, for aquaria, and as a food fish. They have most recently been promoted as an important source of protein that could provide food security for developing countries without the environmental problems associated with terrestrial agriculture. In addition, market demand for tilapia in developed countries such as the United States is growing rapidly.
  • 2. Tilapias are well‐suited to aquaculture because they are highly prolific and tolerant to a range of environmental conditions. They have come to be known as the ‘aquatic chicken’ because of their potential as an affordable, high‐yield source of protein that can be easily raised in a range of environments — from subsistence or ‘backyard’ units to intensive fish hatcheries. In some countries, particularly in Asia, nearly all of the introduced tilapias produced are consumed domestically; tilapias have contributed to basic food security for such societies.
  • 3. This review indicates that tilapia species are highly invasive and exist under feral conditions in every nation in which they have been cultured or introduced. Thus, the authors have concluded that, despite potential or observed benefits to human society, tilapia aquaculture and open‐water introductions cannot continue unchecked without further exacerbating damage to native fish species and biodiversity. Recommendations include restricting tilapia culture to carefully managed, contained ponds, although exclusion is preferred when it is feasible. Research into culture of indigenous species is also recommended.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

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