生态文明视域下山东省海水养殖业发展对策研究

当前在海洋捕捞资源逐渐减少的情况下,海水养殖业的发展显得尤为重要。近年来,山东省积极转变海水养殖发展方式,以推进海水健康养殖示范区建设为切入点,大力提高养殖水产品质量安全水平。但随着海水养殖业的不断发展,对环境产生的负面影响也逐渐显现,如因海水养殖使用过多的饲料和药物污染了海岸和海水环境;海水养殖业的发展影响了生物多样性,     

南非海水养殖业的现状及中南合作前景

文章对南非共和国海水养殖业的发展概况、海水养殖的经济种类、产地分布、养殖产量和科研水平等进行综述,并对中南两国在海水养殖领域未来的合作前景作一展望,旨在为相关专家、学者了解南非海水养殖业的发展现状提供参考。     

我国南海海水养殖环境的集成管理研究

海水养殖业作为海洋渔业的重要支柱,而海洋环境则为海水养殖提供广阔的空间资源,并影响其持续发展。本文在深入剖析南海海水养殖环境污染现状的基础上,指出南海海水养殖环境管理的重点是实现海水养殖业转型升级,并从产业发展与环保关系、立法和创新执法难题、政府与社会的关系、技术与人才瓶颈等方面指明其难点。进而提出构建多主体联合、多区域参与、多管理方式、高协调度的"三高一多"的南海海水养殖环境集成管理模式,以期实现南海海水养殖环境及其管理的优化。     

海水经济鱼类遗传育种研究进展

近二三十年来,海水养殖方式与设备的不断发展与完善,促进了海水养殖业的发展。但是,由于海水经济鱼类缺乏优良品种,大多数养殖种类为野生种或半野生种,许多养殖种群在累代繁殖后,出现品质退化、生长速度慢、发病率高等不良症状,严重地阻碍着海水经济鱼类养殖业的发展。因此,近年来,世界各国纷纷加强海水鱼类的遗传育种研究工作,     

关于建设象山港现代新型海水网箱养殖基地的探讨

海水鱼类养殖的兴起和发展，标志着我国海水养殖业已进入了新的发展时期，即由藻贝虾养殖过渡到鱼类的养殖，而其代表性的养殖方式－浅海网箱养殖又标志着我国海水养殖业向养殖技术的先进性、养殖设施的完整性和养殖方式的集约性方向发展。因此，发展海水网箱将是我国扩大养殖区域，增加养殖面积的主要作业方式，也是人类开发和利用海洋资源、发展海洋经济新的潮流和新的增长点。本文就象山县如何开拓利用象山港浅海资源、发展海水网箱养殖，谈几点看法和认识。     

发展山东省海水健康养殖的构想和主要对策

山东作为海水养殖大省，产量约占全国的1／3。在传统捕捞业面临近海渔业资源枯竭、传统渔场面积减小的形势下，加大现代生物技术、新材料等在海水养殖业中的应用，挖掘海水养殖潜力，推动海水养殖业可持续发展，对于发展渔区经济，增加渔民收入更具有现实意义和历史意义。本文针对山东海水养殖的现状和问题，对健康养殖的发展构想及对策进行了初步探讨。     

舟山海水养殖业风险因素分析研究

海水养殖业在舟山群岛经济建设中发挥了重要作用,全面评估当地海水养殖业中存在的各种风险因素和风险程度,积极探索和研究行为有效的应对机制,对于促进舟山海水养殖业持续、健康、快速发展以及渔区的和谐与稳定具有重要的现实意义.本文分析探讨了舟山海水养殖个体户,合作社以及养殖企业的养殖状况以及在养殖过程中面临的来自各方面的风险因素,并结合舟山具体实际,提出了若干有效可行的应对措施.     

我国海水养殖贝类病害发生现状及防控策略

贝类养殖是我国水产养殖业的重要组成部分，在促进经济社会发展、提高就业率、改善人民生活及保护生态环境等方面发挥了重要作用，其经济、社会和生态功能日益凸显。近年来，因环境胁迫和病原侵染引发的海水养殖贝类暴发性病害时有发生，所造成的经济损失巨大，严重阻碍了海水养殖产业的绿色高质量发展。贝类缺乏适应性免疫，且主要养殖于开放或半开放水体，难以通过疫苗注射或环境调控等手段进行病害防控。贯彻“绿色防控”的理念，加快病害预警预报体系建设是海水养殖贝类病害防控的重要发展方向。本文综述了我国海水贝类养殖及病害发生的现状，并结合团队前期研究和病害预警预报工作实践,提出了海水养殖贝类病害防控策略，以期提升我国水产动物疫病防控能力，为保障水产品稳定安全供给、促进水产养殖业绿色高质量发展提供参考。     

海水养殖业四十年发展成就

海水养殖业是我国水产业的一个重要组成部分。新中国成立以前,海水养殖生产的基础很差,养殖技术落后,产量不足万吨。新中国成立后,社会主义制度的建立,为海水养殖的大发展提供了优越的环境条件。40年来,在党和政府的领导下,经过沿海广大干部、职工和渔(农)民的积极努力,海水养殖业得到     

福建省海水养殖业产量结构特征与发展趋势

海水养殖业合理的结构与良好的发展趋势有利于促进福建省经济的长远发展。本文基于福建省1983—2012年的海产品产量与海水养殖产量数据,研究了福建省鱼类、虾蟹类、贝类、藻类等海产品和海水养殖产品的产量结构特征,结果表明福建省海水养殖主要以贝类、藻类为主,海洋捕捞主要以鱼类、虾蟹类为主;分析了福建省海水养殖的养殖比、面积、单产等的发展趋势,得出鱼类、虾蟹类增加趋势较大,增产潜力大;针对福建省海水养殖产量结构特征和发展趋势,进行成因分析并提出对策。研究结果可以为渔业部门指导福建省海水养殖业的发展提供参考。     

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.