皱纹盘鲍工厂化育苗技术

利用坑道培育和海捕的皱纹盘鲍亲体，进行人工催产、授精；以高密度集中培育浮游幼虫；用以舟形藻、卵形藻和菱形藻为主的底栖硅藻作为开口饵料，进行稚鲍前期培育；以幼鲍专用饲料作稚鲍后期饵料，进行稚鲍后期流水平面培育。1996年在8m2的采苗水面培育出壳长1．0～1．2cm的稚鲍2．4万个；1997年在50m2的采苗水面培育出壳长1．0～1．7cm的幼鲍16万个。     

皱纹盘鲍稚鲍剥离后大量死亡原因研究

针对稚鲍剥离后大量死亡问题，进行稚鲍剥离规格、稚鲍剥离后直接投喂人工合成饵料与继续摄食底栖硅藻的对比试验，结果是：4mm稚鲍剥离死亡率比2mm稚鲍剥离死亡率低得多，稚鲍剥离后投喂人工合成饵料死亡率很高，摄食底栖硅藻，死亡率则很低。     

九孔鲍人工育苗技术探讨

采用阴干加紫外线处理海水催产的方法，进行九孔鲍室内人工育苗研究，使用雌亲鲍1343粒，平均规格5．7cm，雄亲鲍117粒，平均规格5．8cm，共获得受精卵9500万粒，受精率91．5％，以塑料薄膜作为附着基质，共附着匍匐幼体607万粒。经过64～73d的附着期间的管理，剥离0．21～1．0cm稚鲍347万粒，成活率达57．2％，又经过98～102d的培育，获得规格1．0～2．5cm的鲍苗121．5万粒，平均成活率达35．0％。     

关于抑制稚鲍壳质腐蚀方法研究

若在循环过滤海水中长期持续培育稚鲍，则屡屡发生壳顶至中部的壳面遭到腐蚀而珍珠质层裸露现象。在处于同一培育环境时，呈现这种腐蚀状态的稚鲍，出现率往往几乎高达百分之百。与在其它培育环境中养殖的未腐蚀的健壮稚鲍相比，这种珍珠质层裸露的稚鲍，壳的腐蚀部分变薄，用指尖只轻轻一按就很容易玉碎。另外，这样的稚鲍多发育不良。对大批培育苗种来说，这一点尤其值得注意。     

安特消毒剂在皱纹盘鲍稚鲍培育中的应用

在皱纹盘鲍工厂化育苗生产中,稚鲍剥离后大量死亡,育成率低下,是困扰生产单位的一大难题。我们１９９５年和１９９６年在稚鲍培育中,采用安特消毒剂处理稚鲍和培养用水,取得了明显的效果,现报告如下：１材料与方法１．１试验在长岛县第一育苗场进行,稚鲍剥离后在规格为 ９ ｍ×０． ９ ｍ×． ５ ｍ和 １．０ ｍ×． ０ ｍ×０．９ ｍ的培育池中流水充气培养。所用海水经砂滤处理,海水盐度３１．２～３１．８,ｐＨ８．２～８．４。稚鲍主要投喂人工配合饵料,一般傍晚投喂,每天上午７：００～８：００清除残饵。１．２安特消毒剂…     

几种免疫因子对九孔稚鲍免疫力的影响

选用浓度分别为5×10^-6、10×10^-6、0．5×10^-6、1×10^-6的维生素B6（维生素类）、益母草膏（中草药类）、腐殖酸（天然螯和剂）和大蒜素（免疫药物）4种制剂,采用浸浴的方法,对11-39日龄的九孔稚鲍（Haliotis diversicolor supertexta）进行免疫刺激。试验期间每两天换水、补药一次,以维持各组原有的药物浓度,同时对稚鲍的脱板情况进行计数;最后取样测定各组幼体酚氧化物酶、溶菌酶的活性。试验结果表明。各药物组的酚氧化物酶和溶菌酶含量均显著高于对照组（p〈0．05）,且稚鲍成活率亦有显著性提高。试验结束时大蒜素组的成活率最高,可达60．00±3．33％;其次为益母草膏、腐殖酸和维生素B6组,成活率分别为56．60±1．66％、45．05±2．44％和42．67±3．13％;均极显著高于对照组的8．59±7．14％（0〈0．01）。由此可见,增强机体的抗氧化能力可提高稚鲍的成活率;本试验所选用的4种免疫因子均可提高九孔稚鲍的免疫力．能有效地提高鲍鱼的附板率。     

皱纹盘鲍稚鲍的酒精麻醉剥离试验

皱纹盘鲍(Haliotis discus hannai Ino)稚鲍的剥离，是的人工育苗工艺中不可缺少的作业环节。关于稚鲍的剥离方法，国外曾有过一些报道，如日本，用氨基甲酸乙酯或对氨基苯甲酸乙酯等药物麻醉剥离已成为近年来较普遍应用的剥离方法。对10毫米以上的稚鲍用温水剥离有时也作为一种有效的实用方法之一。     

稚鲍网箱饲育期给水量的探讨

稚鲍在网箱饲育期间给水量的多少，是直接关系到饲育水质能否保持正常、稚鲍的生长能否受到影响的重要工艺指标之一。给水量不足，将可能导致饲育水质的逐步恶化，稚鲍的摄食与生长将因此而受到影响，给水量增大，又将要提高对供水设施的要求，增加水电消耗。     

稚鲍人工流水饲育方法的研究

在鲍鱼人工育苗过程中、稚鲍期是历时最长的阶段，这一时期的饲育方法是否得当，直接左右人工育苗的效果。在稚鲍培育前期，即采苗板培育阶段，底栖硅藻饵料如不能满足，则往往导致稚鲍生长缓慢、成活率低，单位水面出苗量不高。特别是当稚鲍进入壳长3-5毫米以后，由于摄食能力的增强，如果继续使用采苗板方式培育，     

关于玛瑙鲍的探索与研究

选择皱纹盘鲍（Ｈａｌｉｏｔｉｓ ｄｉｓｃｕｓ ｈａｎｎａｉ）的变异个体－－贝壳为红色的玛瑙鲍（Ａｇａｔｅ Ａｂａｌｏｎｅ）作亲体,进行人工繁殖的培育。发现在性产物排放诱导率、孵化率、幼虫附着率和稚鲍生长等方面,玛瑙鲍与皱纹盘鲍大致相同。但稚鲍对不良环境（如赤潮）的抗性,玛瑙鲍明显强于皱纹盘鲍,３２ｄ存活率,前者为６３．１％,后者为３４．３％。ＬＤＨ电泳图谱显示,玛瑙鲍内脏组织中ＬＤＨ活性较高,而被     

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).     

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.     

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.