东海区海蜇生产与东太平洋赤道海温关系的初步探讨

海蜇(Rhopilema csculenta Kishinouye)广泛分布于我国沿岸。其成品经济价值较高，是国内外副食品市场上的畅销水产品之一。我国渔民历来有捕捞海蜇的习惯。解放后，以定置网张捕为主要作业的捕捞生产已被广泛重视。海蜇是一种繁殖力强，生命周期短的水产经济动物。三十年来，     

《2002年中国水产品进出口贸易统计年鉴》开始征订

近年来,我国水产品进出口贸易取得了举世瞩目的成就。2002年我国水产品出口首次名列世界第一,出口额达到46.9亿美元。为增强水产品出口企业的国际市场竞争力,加强我国与国际水产企业的交流与合作,农业部渔业局委托中国水产学会编辑出版了大型工具书《2002年中国水产品进出口贸易统计年鉴》(中英文对照版)。目前,此书的征订工作已经开始。该书主要内容有:2002年中国水产品进出口品种情况;对世界各个国家进出口情况;分国家、品种进出口情况;分品种、国家进出口情况;分省、品种进出口情况;分品种、省进出口情况;分贸易方式进出口情况;中华人民…     

夏日食药兼优佳品——海蜇

海蜇又称水母,属海产腔肠动物,是我国沿海特别是东南沿海的重要水产品之一,从南至北,每年4～9月为捕捞上市季节,华南沿海一般春夏季为旺产期.……     

专业图书超市

近年来，随着全球渔业的发展和水产品消费需求的不断增加，水产品国际贸易发展迅速，全球水产品总量约有30％进入国际贸易，贸易总额已达500多亿美元。我国是水产品生产与贸易大国，产品出口150多个国家和地区。2003年我国水产品进出口总量为443万吨，进出口总额达到79．7亿美元，在全球水产品贸易中具有举足轻重的影响。     

2000年我国水产品市场运行分析与展望

２０００年，我国渔业经济继续保持良好的发展态势，水产品产量适度增长，水产品市场运行平稳，价格止跌回升。进出口贸易增势强劲。去年我国水产品总产量为４２７８．９９万吨，比１９９９年增加１５６．５万吨，增长３．８％；其中海水养殖１０６１．２８万吨，增加８６．９８万吨，增长８．９３％；海洋捕捞１４７７．４５万吨，减少２０．１６万吨，递减１．３５％；内陆养殖 １５１６．９３万吨，增加 ９４．９６万吨，增长 ６．６８％。内陆捕捞２２３．３２万吨，减少５．２万吨，递减２．２８％；水产品进出口贸易增势强劲，据海关…     

辽东湾海蜇生产网具结构规格的探讨

<正> 辽东湾海蜇资源相当丰富,其年产量约占全国总产量的30%左右。我省沿岸渔民捕捞海蜇生产的历史悠久。但在六十年代以前,被列为三类水产品,经济价值较低,因此,很少有专门从事捕捞海蜇的渔船和网具。七十年代以后,海蜇进入国际市场,出口价格较高,已被国家列为全额收购的海产品,从     

水产加工业可追溯性管理与海洋渔业可持续性发展

水产品是一种健康的且不断更新的食品来源。水产品经济也是全球渔业贸易的重要组成,同时也为全球生活和就业做出了重要贡献。据《2008年世界渔业和水产养殖状况》统计[1],2006年,全球捕捞渔业产量约为9.2×107 t,其中海洋捕捞产量为8.2×107 t。亚洲国家占全球捕捞产量的52%;我国依     

辽东湾海蜇渔业的捕捞方式

辽东湾海蜇渔业的捕捞方式修林海王文波，叶昌臣（营口渔业公司）（辽宁省海洋水产研究所，大连１１６０２３）关键词：辽东湾，海蜇，捕捞方式辽东湾海蜇渔业是辽宁省近岸渔业中的主要渔业之一，约有１０，０００条小型渔船参加作业，年产量一般都超过１０，０００吨矾制...     

海水产品贸易对海洋渔业资源环境的影响——以浙江省为例

水产品贸易是浙江省对外贸易中的支柱产业之一,它与海洋渔业资源环境密切相关。文章利用1985￣2004年的数据,分析了水产品出口、渔船数量与海洋捕捞之间的关系,检验结果表明,水产品贸易与海洋捕捞之间成负二次相关关系,说明随着水产品贸易的发展,海洋捕捞有一个最大值,超过了这一限度,将破坏其最大可再生资源。     

入世以来中国水产品贸易的格局特征及发展前景

水产品是中国传统的出口优势产品。加入WTO以来,中国水产品贸易在进出口双向快速增长的局面下,保持了净出口态势。文章在总结中国水产品入世几年来进出口的发展趋势、产品结构以及国别特征的基础上,着重分析了其发展前景。结果表明,增强质量竞争力是优势水产品出口实现持续增长的关键,未来几年对国外捕捞类水产品进口将继续大规模增长,中国水产品进出口的产品结构特征短期内不会有显著变化。最后,基于提高出口水产品竞争力、优化中国水产品贸易格局的目的提出了一些对策建议。     

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 hormone (GH) and reproduction: a review

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.     

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).     

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.     

Imported ornamental fish are colonized with antibiotic‐resistant bacteria

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.     

Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load

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.     

Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)

The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I^–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg^–1 fish·h^–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g^–1·ml^–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min^–1·g^–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min^–1·g^–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.