5种常用渔药对点篮子鱼幼鱼急性毒性试验

在水温29.2～30.4℃、盐度30～32条件下,进行了敌百虫、甲醛、聚维酮碘、硫酸锌、硫酸铜与硫酸亚铁(5∶2)合剂5种常用渔药对点篮子鱼(Siganus guttatus)幼鱼急性毒性试验。结果显示:5种药物的安全浓度分别为0.91、54.99、17.10、23.88、1.77 mg.L-1。点篮子鱼对5种药物敏感度的大小顺序为:敌百虫>硫酸铜与硫酸亚铁合剂>聚维酮碘>硫酸锌>甲醛。     

几种常见水产药品对日本黄姑鱼幼鱼的急性毒性试验

摘 要：采用静水法,用高锰酸钾、二溴海因、CuSO4•FeSO4合剂（5：2）、敌百虫、阿维菌素、二氧化氯等6种水产药品对体长5.73±1.50cm、体重2.00±0.32g 的日本黄姑鱼幼鱼进行了急性毒性实验,得出6种药品对日本黄姑鱼幼鱼24、48、96h的半致死浓度,高锰酸钾1.37、1.26、1.24mg/L;二溴海因10.59、8.61、7.86mg/L;CuSO4•FeSO4合剂2.57、1.76、1.43mg/L;敌百虫1.72、1.43、1.18 mg/L;阿维菌素0.30、0.23、0.19mg/L;二氧化氯3.34、2.821、1.66mg/L;六种药物的安全浓度依次为0.12、0.79、0.14、0.12、0.019、0.17 mg/L。     

4种常用水产药物对锦鲤幼鱼的急性毒性

在水温23.0~25.0℃下研究不同剂量的硫酸铜与硫酸亚铁合剂(5∶2)、甲醛、敌百虫、聚维酮碘对体质量(25.0±2.0)g锦鲤Cyprinus carpio幼鱼的急性毒性及其评价方法。结果表明,硫酸铜与硫酸亚铁合剂(5∶2)、甲醛、敌百虫、聚维酮碘对锦鲤幼鱼的24 h半致死浓度为6.75mg·L~(-1)、78.77mg·L~(-1)、5.95mg·L~(-1)、96.39mg·L~(-1),48h半致死浓度为5.12mg·L~(-1)、49.52mg·L~(-1)、4.28mg·L~(-1)、70.88mg·L~(-1),安全浓度为0.88mg·L~(-1)、5.87mg·L~(-1)、0.67mg·L~(-1)、11.49mg·L~(-1)。4种药物毒性大小依次为:敌百虫硫酸铜与硫酸亚铁合剂(5∶2)甲醛聚维酮碘。本研究结果可为预防和治疗锦鲤苗种疾病提供参考。     

鲫鱼寄生麦穗碘泡虫病治疗技术

选用CuSO4与FeSO4(5∶2 )混合液 0 7× 10 -6与敌百虫 0 15× 10 -6全池泼洒 ,可去除鲫鱼体内的麦穗碘泡虫     

4种常用水产药物对丁鱼种的急性毒性实验

在常温静水条件下,4种常用水产药物对丁鱼岁(Tincatinca)鱼种急性毒性实验结果表明:安全浓度为硫酸铜硫酸亚铁合剂(5∶2)0.84mg/L,福尔马林7.50mg/L,敌百虫8.57mg/L,高锰酸钾0.85mg/L。丁鱼岁对这4种药物的敏感性大小为:硫酸铜硫酸亚铁合剂>高锰酸钾>福尔马林>敌百虫。敌百虫可作为丁鱼岁疾病防治用药,硫酸铜硫酸亚铁合剂应谨慎使用,福尔马林和高锰酸钾不宜施用。     

四种水产药物对硬刺松潘裸鲤幼鱼的急性毒性试验

在溶氧(7.0±0.3)mg/L,水温(18±1)℃,pH 7.8±0.1条件下,采用国家标准半静态方式水生生物急性毒性实验法研究了高锰酸钾、硫酸铜与硫酸亚铁合剂(5∶2)、敌百虫和甲醛对硬刺松潘裸鲤(Gymnocypris potanini firmispinatus Wu et Wu)幼鱼的急性毒性试验。试验结果显示,高锰酸钾、硫酸铜与硫酸亚铁合剂、敌百虫和甲醛对硬刺松潘裸鲤幼鱼的24 h半致死浓度(24 h LC50)分别为4.57、2.74、8.00和54.69 mg/L,48 h半致死浓度(48 h LC50)分别为4.13、2.35、7.34和47.03 mg/L;96 h半致死浓度(96 h LC50)分别为3.37、1.92、4.76和40.44 mg/L;其安全浓度分别为1.01、0.52、1.85和10.43 mg/L。根据国家标准和本实验数据表明,甲醛对硬刺松潘裸鲤幼鱼微毒,高锰酸钾、硫酸铜与硫酸亚铁合剂和敌百虫对其中毒。     

几种药物对月鳢的急性毒性

1　材料和方法1 1　试验鱼为本所繁殖的当年健康鱼苗 ,体长 4 4～ 7ｃｍ ,试验前先在水族箱中饲养 7天 ,试验期间不投喂饲料。1 2　试验药物孔雀石绿 (指示剂 )、甲醛 (分析纯 )、盐 (分析纯 )、硫酸铜 (分析纯 )、敌百虫 ( 90 %晶体 )、强氯精 (有效氯 90 %以上 )。1 3　试验条件试验容器直径 2 8 5ｃｍ ,高 53ｃｍ ,水的体积为10Ｌ的圆形玻璃瓶 ,试验用水经 2 4小时曝气的自来水 ,每瓶放鱼 10尾 ,瓶上加盖网布 ,防鱼逃出。试验期间水温 2 3～ 2 6℃ ,ｐＨ值 7 2～ 7 5,溶氧量为 4 8～ 6 1ｍｇ/Ｌ。1 4　试验方法先根据鱼病防治的常用剂…     

4种渔药对昆明裂腹鱼鱼苗的急性毒性试验

采用半静水式试验方法研究了在水温(16.5±0.5)℃、pH(7.70±0.25)条件下,高锰酸钾、三氯异氰尿酸、硫酸铜与硫酸亚铁合剂(5∶2)、敌百虫4种常用渔药对昆明裂腹鱼(Schizothorax grahami)鱼苗的急性毒性实验。结果显示:4种药物中三氯异氰尿酸的24 h、48 h、96 h半致死浓度最低,分别为1.586、1.423、1.173 mg/L,敌百虫的最高,为473、407、302 mg/L。4种药物的安全浓度分别为高锰酸钾0.536 mg/L,三氯异氰尿酸0.347 1 mg/L,硫酸铜与硫酸亚铁合剂(5∶2)0.5 mg/L,敌百虫90.41 mg/L。结果表明:4种药物中,三氯异氰尿酸、硫酸铜与硫酸亚铁合剂(5∶2)和敌百虫可在生产中安全使用。     

乌苏里拟鲿对6种常用渔药的耐受性试验

为了解乌苏里拟鲿对氧化钙、硫酸铜硫酸亚铁合剂(5∶[KG-*1/2]2)、三氯异氰尿酸、敌百虫、聚维酮碘、氯化钠等6种常用渔药的耐受性,在水温28±2 ℃,pH值7.2~8.3,溶氧量4.3~5.6 mg·L-1条件下,将全长3.3~5.8 cm、体质量0.32~1.46 g的当年鱼苗放入不同浓度的上述6种药物的药液中进行耐受性试验。试验结果:聚维酮碘、硫酸铜硫酸亚铁合剂(5∶[KG-*1/2]2)、敌百虫、三氯异氰尿酸、氧化钙、氯化钠对乌苏里拟鲿的96 h半致死浓度依次递减;6种药物对乌苏里拟鲿的安全浓度依次为0.01、0.01、0.06、0.25、7.12和3 347 mg·L-1,均低于防治鱼病常规使用浓度。结果表明,乌苏里拟鲿对氧化钙、硫酸铜硫酸亚铁合剂(5∶[KG-*1/2]2)、三氯异氰尿酸、敌百虫、聚维酮碘的耐受性较弱,应慎用;对氯化钠的耐受性较强,可以用2 %的浓度进行药浴,当水温低于26 ℃,药浴时间少于55 min时尚属安全。     

鱼病流行季节前的药物预防

1 体外鱼病的预防一般采用定期用药遍洒鱼池。漂白粉在细菌性鱼病流行季节，每半月泼洒1次，用量1克/米3。生石灰水每667米2水深1米施生石灰15～20千克，可改良水质，杀灭水中致病菌。硫酸铜和硫酸亚铁合剂预防寄生性鱼病，如鳃隐鞭虫、口丝虫病、斜管虫病、车轮虫病和中华鳋病等，每月或每两月进行1次，使池水呈0.7克/米3浓度(硫酸铜和硫酸亚铁之比为5∶2)。敌百虫全池泼洒90％晶体敌百虫，使池水呈0.2～0.5克/米3浓度，对指环虫、三代虫、中华鳋的幼虫有较好的杀灭效果。体外鱼病药物预防还可采用食场消毒法进行。在使用时要使药物充分溶…     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

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.     

Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China

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.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

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.     

Evaluation of a Fast Method Based on the Presence of Two Restriction Sites in the Mitochondrial ND5 (mt ND5) Gene for the Identification of Scomber Species

The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.     

Purification and partial characterization of GtHs (cfLH and cfFSH) from Indian walking catfish (Clarias batrachus) (L.) and development of a homologous ELISA for cfLH

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.     

Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection

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).     

The optimal dietary protein level of juvenile silver sillago Sillago sihama at three dietary lipid levels

A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

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.