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1.
碱度、pH对中国林蛙蝌蚪成活的影响   总被引：3，自引：0，他引：3  
在水温16～18℃的野外条件下,采用单因子静态急性毒性实验法,研究水环境中碱度、pH对中国林蛙(Ranachensinensis)蝌蚪的毒性效应。结果表明,在pH为7 0～8 5、盐度为0 18g/L时,碱度对中国林蛙蝌蚪的24,48,72,96h的半致死值(LC50)分别为14 36,11 8,10 35,7 68mmol/L,安全值(SC)为2 41mmol/L。在相同盐度下,碱度为1 41mmol/L时,pH对中国林蛙蝌蚪的24、48、72和96hLC50值分别为10 33(3 92),10 18(4 07),10 08(4 11),10 02(4 16)。蝌蚪长期生长与生存的pH为6 0～9 0,碱度上限为3 0mmol/L。  相似文献   

2.
达里湖鲫对盐度和碱度突变和渐变的耐受性   总被引：1，自引：0，他引：1  
研究了达里湖鲫(Carassius auratus Linnaeus))幼鱼在盐度、碱度突变和渐变条件下的耐受性,并对在不同盐度和碱度浓度下的累计存活率、生存上限进行比较分析。研究发现,盐度突变条件下24、48、72和96 h的半致死浓度(LC50值)分别为11.795、11.089、10.809和10.534 g/L;碱度对试验鱼24、48、72和96 h的LC50分别为69.831、68.779、67.071和65.114 mmol/L。渐变条件下达里湖鲫的盐碱耐受能力均强于突变组,其碱度渐变组生存上限为109.2 mmol/L,明显高于突变组的90 mmol/L;盐度渐变组生存上限为15 g/L,与突变组差异不显著。结果表明,通过适当的驯养适应,可以显著提高达里湖鲫对碳酸盐型水质环境的适应能力和养殖的存活率。  相似文献   

3.
三种鳅科鱼对NaCl盐度和NaHCO3碱度的耐受能力   总被引：2，自引：0，他引：2  
以鳅科的黑龙江泥鳅(Misgurnus mohoity Dybowsky)、大鳞副泥鳅(Paramisgurnus dabryanus Sauvage)、达里湖高原鳅(Triplophysa dalaica)为实验材料,采用单因子静态急性毒性实验法和均匀正交设计法对其盐碱耐受能力进行研究。实验结果表明,黑龙江泥鳅、大鳞副泥鳅、达里湖高原鳅的24 h和96 h的氯化钠(Na Cl)盐度半致死浓度(LC50)分别为15.64 g/L和13.58 g/L、15.43 g/L和14.18 g/L、14.00 g/L和11.57 g/L,安全浓度(SC)分别为4.12 g/L、4.03 g/L、3.74 g/L,盐度耐受能力顺序为:黑龙江泥鳅大鳞副泥鳅达里湖高原鳅。黑龙江泥鳅、大鳞副泥鳅、达里湖高原鳅的24 h和96 h碳酸氢钠(NaHCO_3)碱度半致死浓度(LC50)分别为117.1 mmol/L和72.62 mmol/L、128.4 mmol/L和88.83 mmol/L、155.2 mmol/L和120.0 mmol/L,安全浓度分别为18.77 mmol/L、23.66 mmol/L、36.30 mmol/L,碱度耐受能力顺序为:达里湖高原鳅大鳞副泥鳅黑龙江泥鳅。盐碱交互作用对黑龙江泥鳅、大鳞副泥鳅均表现为协同作用,协同系数0~48 h依次增高,以后逐渐减小;而对达里湖高原鳅在0~48 h内表现为协同作用,在48~96 h时表现为拮抗作用,拮抗系数随着暴露时间的延长而增大。对比分析可知,3种鳅科鱼的盐碱耐受能力比大多数淡水鱼高,可作为盐碱水域的增养殖鱼类;而达里湖高原鳅在耐碱方面表现更突出,可以作为高碳酸盐型盐碱水的增养殖鱼类。  相似文献   

4.
铜(Cu2+)对麦穗鱼苗的急性毒性与非生物因子的相关性研究   总被引：5，自引：0，他引：5  
黄斌  别立洁 《淡水渔业》2006,36(2):34-38
研究了不同温度、pH值和碱度条件下铜离子对麦穗鱼苗的急性毒性,结果表明:随水温升高,铜(Cu2+)对鱼苗的急性毒性明显加剧,温度为20℃、26℃、32℃时,96 h的LC50分别为0.035 mg/L、0.024 mg/L、0.018 mg/L;而铜(Cu2+)的急性毒性与pH值和碱度的相关性较复杂,低pH值、低碱度时,铜(Cu2+)的急性毒性相对较弱,但当pH值和碱度上升到一定数值后,铜(Cu2+)的急性毒性随着pH值和碱度的升高而加剧。pH值为6.7、7.5、8.8时,96h的LC50分别为0.022 mg/L、0.027mg/L、0.026 mg/L。碱度为0.79 mmol/L、1.30 mmol/L和1.65 mmol/L时,96 h的LC50分别为0.027 mg/L、0.075 mg/L、0.049 mg/L。鱼苗急性中毒表现为:体表分泌粘液增多,眼球突出,脑颅、鳃部充血,肝脏、肠道淤血。  相似文献   

5.
盐度和碱度对克氏原螯虾的联合毒性试验   总被引：7，自引：0，他引：7  
用寇氏法(Karber法)研究了盐、碱对克氏原螯虾(Procambarusclarkii)的急性毒性作用,并采用相加指数法(Mark-ing指数法)研究了盐碱联合作用对克氏原螯虾的影响。结果表明:盐度对克氏原螯虾24h、48h、72h、96h的半致死浓度(LC50)分别为31.74g/L、27.21g/L、26.45g/L、26.09g/L,其安全浓度是6.00g/L。碱度对克氏原螯虾24h、48h、72h、96h的半致死浓度分别为12.00g/L、10.64g/L、8.36g/L、7.58g/L,其安全浓度是2.51g/L。盐碱在1:1毒性单位混合后,对克氏原螯虾的作用效果在不同时间段均表现为一定的拮抗作用。  相似文献   

6.
吡喹酮、甲苯咪唑、溴氰菊酯对花鳗鲡的急性毒性   总被引：1，自引：0，他引：1  
采用静水式急性毒性试验法研究了吡喹酮、甲苯咪唑和溴氰菊酯对花鳗鲡(Anguilla marmorata)(体重为0.87±0.19 g)的急性毒性。试验结果表明,在水温28±2℃时,吡喹酮对花鳗鲡的24 h LC50、48 h LC50、72 h LC50、96 h LC50分别为73.85 mg/L、66.71 mg/L、56.57 mg/L、52.72 mg/L,安全浓度为16.34 mg/L;甲苯咪唑对花鳗鲡的24 h LC50、48 h LC50、72 h LC50、96 h LC50分别为142.81mg/L、13.80 mg/L、5.19mg/L、1.74mg/L,安全浓度为0.023 mg/L;溴氰菊酯对花鳗鲡的24 h LC50、48 h LC50、72 h LC50、96 h LC50分别为9.56μg/L、9.34μg/L、7.69μg/L、7.67μg/L,安全浓度为2.68μg/L。吡喹酮、甲苯咪唑、溴氰菊酯对花鳗鲡分别属于低毒、中毒、剧毒药物。甲苯咪唑对花鳗鲡的安全浓度0.023 mg/L远低于欧洲鳗鲡(Anguilla anguilla)的常用浓度1～2 mg/L,因此在花鳗鲡养殖中使用甲苯咪唑制剂需十分谨慎。  相似文献   

7.
4种常用药物对克氏双锯鱼稚鱼急性毒性试验   总被引：2，自引：1，他引：1  
选用硫酸铜、敌百虫、福尔马林、上野黄药对克氏双锯鱼稚鱼进行急性毒性试验.硫酸铜对克氏双锯鱼稚鱼24 h LC50为0.80 mg/L,48 h LC50为0.70 mg/L,96 h LC50为0.60 mg/L,安全质量浓度为0.16 mg/L;敌百虫对克氏双锯鱼稚鱼24 h LC50为2.88 mg/L,48 h LC50为2.44 mg/L,96 h LC50为2.12 mg/L,安全质量浓度为0.53 mg/L.福尔马林和上野黄药对克氏双锯鱼稚鱼的96 h LC50＞100 mg/L,属于低毒.根据96 h半致死质量浓度来判断药物的毒性大小,克氏双锯鱼稚鱼对4种药物敏感性依次为:硫酸铜>敌百虫>福尔马林和上野黄药,福尔马林和上野黄药对克氏双锯鱼稚鱼同属于低毒药品.  相似文献   

8.
探讨了硫酸铜对栉孔扇贝的24、48、72、96 h的毒性,并计算出硫酸铜对栉孔扇贝的24、48、72、96 h的半致死质量浓度(LC50)分别为(0.32±0.099)mg/L、(0.112±0.022)mg/L、(0.074±0.005)mg/L、(0.063±0.005)mg/L,安全质量浓度为0.012 mg/L...  相似文献   

9.
瓦氏雅罗鱼Leuciscus waleckii是一类对高碳酸盐水环境具有耐受力的鱼类。为明确其在高碱环境下各项生理反应和健康状况,本研究对瓦氏雅罗鱼的两种地理种群达里诺尔湖瓦氏雅罗鱼(简称碱水雅罗鱼, Alkaline Water, AW)和松花江瓦氏雅罗鱼(简称淡水雅罗鱼, Fresh Water, FW)进行2个NaHCO_3碱度组(30 mmol/L和50 mmol/L)和1个淡水对照组20 d的碱胁迫实验,通过酶标仪对血清中的碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、尿素氮(BUN)、血氨(Amon)和乳酸脱氢酶(LDH)进的活性进行测定。结果表明,在高碳酸盐碱度环境下,碱水、淡水两种瓦氏雅罗鱼的AKP、ACP、BUN和Amon均呈现碱胁迫组高于对照组的变化,并且两种瓦氏雅罗鱼的指标在30 mmol/L具有显著差异(P0.05),其中BUN与Amon还呈现出30 mmol/L组高于50 mmol/L组的趋势。LDH的变化不明显。综合来看,达里诺尔湖瓦氏雅罗鱼对碳酸盐胁迫的适应能力与松花江瓦氏雅罗鱼明显不同,碱水雅罗鱼对碱水环境启动了一定程度的调控机制,对高碳酸盐碱度具有更高的耐受能力。  相似文献   

10.
温度(25±1) ℃、盐度20±1时研究了不同碱度下高pH对蒙古裸腹溞存活、生长和生殖的影响.试验结果表明,碱度的升高会降低蒙古裸腹溞对pH的耐受高限:海水的碱度为(0.19±0.1)、(1.99±0.1)、(3.92±0.1)、(5.95±0.1) mmol/L时,蒙古裸腹溞对pH 24 h 中间耐受水平(TLm)分别为10.50、10.15、10.07、9.50;对pH 48 h TLm分别为10.09、9.88、9.81、9.08.蒙古裸腹溞在培养液pH为9.0～9.3时,生长率和存活率相对优越于其他各组.pH 9.0时,蒙古裸腹溞的内禀增长率最大为0.5145/d;pH 9.3时次之,为0.5099/d.  相似文献   

11.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

12.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

13.
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   

14.
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15.
Growth hormone (GH) and reproduction: a review   总被引：5，自引：0，他引：5  
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.  相似文献   

16.
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   

17.
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   

18.
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.  相似文献   

19.
Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.  相似文献   

20.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

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