胶州湾中国对虾增殖放流适宜量的研究

依据１９８５－１９９０年胶州湾对虾放流增殖结果，对放流增殖适宜量进行了研究，结果：超过一定数量之后，随放流数量的增加，增殖对虾体长瞬时生长速度参数下降，二者呈ＫＬ＝３．５９５０ｅ＾７．４７４０＊１０＾－５Ｎ负相关关系。从开捕时增殖对虾平均体长、资源量与放流数量的关第式分析，胶州湾放流中国对虾数量以６５００－８０００万尾为宜。     

城阳区人工放流对虾苗种首次突破一亿尾

近日，城阳区海洋与渔业局分三批次放流增殖对虾首次突破亿尾，达到1．02亿尾。为胶州湾海域水生动物保护行动增添了新光彩。这次水生动物人工增殖活动共放流7700万尾体长平均达到0．8cm的日本对虾苗种和2500万尾均长3cm的中国对虾苗种。与去年相比。新增3700万尾，将对丰富胶州湾生物多样性和沿海渔民增收致富产生积极的影响。     

乳山湾、塔岛湾增殖中国对虾适宜放流量的研究

根据1984～1992年乳山湾、塔岛湾中国对虾(Penaeus chinensis)放流增殖结果,对增殖适宜量进行研究。结果表明随着放流数量的增加,增殖对虾体长瞬时生长速度参数下降,二者呈负相关关系,关系式为kL     

山东半岛南部沿岸中国对虾放流数量对秋汛产量的影响

根据１９８３～１９９８年山东半岛南部沿海对虾放流增殖结果,对秋汛对虾产量与放流数量之间的关系进行了研究。结果表明：秋汛对虾产量随放流数量的增加而增加,二者呈Ｙ＝３６３．７＋１２６．４Ｘ相关关系（ｒ＝０．９１８）。     

东吾洋中国对虾的移植放流

1986～1990年在东吾洋水域放流中国对虾(Penaeus orientalis)种苗70919万尾,其中96.2%是末经中间培育,体长为8～15mm 的仔虾。共回捕对虾917t,年平均回捕率5.02%,优化了东吾洋对虾种类结构和数量组成。东吾洋中国对虾移植性放流增殖取得了显著的经济、社会和生态效益。还探讨了东吾洋中国对虾的放流时间、海区和增殖前景。     

辽东湾中国对虾标志放流及其增殖效果的研究

本文根据辽东湾中国对虾标志放流实验与重捕资料，对辽东湾中国对虾放流场的选择、种苗的放流规格和放流增殖效果进行了研究。根据上述实验分析表明，在辽河口海区进行对虾放流增殖是较理想的场所，在秋汛生产期洄游分布遍及辽东湾传统的中心渔场；放流种苗的适宜体长规格为5cm以上，回捕率较高，最高达3．31％。这将对辽东湾生产性对虾放流提供科学的依据。     

乳山湾殖放流数量再创新高

从2009年5月份开始。河北省在沿海海域进行了规模空前的海洋渔业资源人工增殖放流活动。共增殖体长1．2cm以上的中国对虾6．5亿尾。三疣梭子蟹Ⅱ期大眼幼体333．3kg,体长8cm以上的牙鲆鱼156．3万尾,壳高2～3cm的毛蚶6800kg。伞径2～3cm的海蜇1000万头．滩涂贝类6667kg。截止7月24日,河北省2009年省财政增殖放流项目任务、中国对虾追加放流任务均已全面完成。     

丰南区海捕对虾再获好收成

为恢复近海对虾资源,提高沿海捕捞渔民收入,在近几年连续放流中国对虾的基础上,今年丰南区农牧局继续进行了中国对虾增殖放流工作。各级渔业主管部门共在该区投人中国对虾增殖放流资金180万元,放流体长1.2cm的虾苗3．6亿尾,仅次于2009年的3．9亿尾。     

东吾洋中国对虾小规格仔虾种苗放流技术及其增殖效果

根据１９８６－１９９５年在东吾洋放流的９７９４８万尾中国对虾种苗资料。研究了仔虾种苗放流技术和增殖效果,结果表明,只要掌握好种苗放流技术,加强海区管理,直接放流未经中间暂养培育,平均体长在１０ｍｍ以上的仔虾种苗,年平均加捕率可达５．２６％,增殖效果十分显著。     

关于大亚湾斑节对虾人工增殖的设想和建议

一、国内外对虾放流增殖简况 据有关资料报道，日本濑户内海在70年代初期，对虾产量仅为466吨，尔后通过每年向海湾投放虾苗1-1.5亿尾，到1975年使对虾产量上升到1230吨．我国渤海湾在80年代进行中国对虾人工增殖，把体长3厘米的虾苗放流入海，经70天左右可以生长到16厘米，回捕率达10%以上，据推算每放流工万尾虾苗，可增产对虾35公斤，     

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).     

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.     

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.     

Influence of the antibacterial herbs, Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia on the survival, growth and bacterial load of Penaeus monodon post larvae

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.