尼罗罗非鱼与萨罗罗非鱼及其正反杂交后代的微卫星分析

微卫星（microsatellite）技术是近年来广泛应用的DNA标记，具有重复性好、较易操作和共显性的特点。在硬骨鱼类中表现出高度多态性，已在家系鉴定、遗传作图、群体遗传分析、育种以及系统发生研究等多个领域得到应用。尼罗罗非鱼（Oreochromis niloticus）是我国主要淡水养殖鱼类，生长快，耐盐能力一般；萨罗罗非鱼（Sarotherodon melanotheron）耐盐能力强，适合咸淡水养殖，但生长较慢。[第一段]     

奥尼罗非鱼的人工育苗技术

罗非鱼系鲈形目丽鱼科罗非鱼属，属热带性鱼类，共有100多种，多数产于非洲。罗非鱼具有生长快、食性广、繁殖力强、病害少、肉质好、产量高等特点。目前养殖的主要品种有：奥尼罗非鱼、吉富罗非鱼、吉奥罗非鱼等10多个品种。奥尼罗非鱼是奥利亚罗非鱼（6）和尼罗罗非鱼（早）杂交的后代，是中国目前主要养殖的罗非鱼种类。我国南方沿海地区适宜罗非鱼养殖的区域广阔，罗非鱼养殖具有巨大的开发潜力和有利条件。本文将奥尼罗非鱼人工育苗技术介绍如下：     

中国罗非鱼养殖现状及发展前景

罗非鱼属热带性鱼类,具有生长快、繁殖力强、食性杂、病害少、抗病力强、适应性强等特点,适宜于淡水、海水、网箱、流水池高密度集约化养殖,我国罗非鱼养殖最近十几年中迅速发展,１９９８年产量为５３万吨,占世界产量７０%。一、我国罗非鱼养殖情况１．罗非鱼被引入中国１９５６年我国从越南首次引入莫桑比克罗非鱼（Ｍｏｓｓａｂｉｃａｔｉｌａｐｉａ）,当时称它越南鱼,又因其形状似鲫鱼,故又称为非洲鲫鱼,此后先后引入各种罗非鱼,如１９７８年由长江水产研究所从苏丹境内引进的尼罗罗非鱼（简称沙尼罗）;１９８３年、１９９２年,由淡水渔…     

吉富罗非鱼人工催产技术研究

吉富品系尼罗罗非鱼（以下简称吉富鱼，GIFTstrainofOreochromisniloticus）是由国际水生生物资源管理中心经混合选育获得的优良品系。吉富罗非鱼具有生长快、养殖周期短、产量高、群体繁殖力强、对环境适应性强以及抗病力强等特点，目前是我国罗非鱼养殖的主要品种之一。     

雄性化奥尼罗非鱼海水池塘养殖试验

子一代奥尼雄性化罗非鱼除具有食性广泛、适应性强、生长快等罗非鱼的一般优点外，还具有抗逆性强、品质好等特殊性状，是优良的淡水养殖品种。为拓宽其养殖渠道，我们承担了日照科委下达的“罗非鱼雄性化海水育苗与养殖”项目。现将其养殖技术报告如下：一、试验条件1．池塘为本场对虾养殖池塘，长方形，长12Om、宽72m，面积13亩，其地底为硬泥，池底四周有一条宽3m深40cm的环水沟。池塘平均水深1．3m，过排水方便，有提水设备。2．鱼苗取自本场用海水繁殖的尼罗罗非鱼雌性内奥利亚罗非鱼（雄性）杂交的子一代奥尼罗非鱼苗，雄性率为90％…     

狠抓奥尼鱼苗质量确保提高养殖效益

1976年联合国粮农组织据罗非鱼具有食物链短、生长快、抗病力强、易养、肉质鲜美的优点，向世界推荐作为养殖对象。在许多国家及地区，罗非鱼的养殖和发展很快，产量迅速增加。但人们同时也发现罗非鱼在成鱼养殖过程中有过度种内繁殖的习性，造成密度过大，产量不高，商品率低，效益差的问题。为此，开展研究各种方法解决问题，     

生物技术在水产养殖中的应用

生物技术是现代生物学中发展最为迅速的一个领域，由于其极高的应用价值，得到了世界各国的重视，列为２１世纪的重点科技发展领域。同样，水产生物技术在解决水产业技术难题、开拓新领域、改造传统产业中也具有十分重要的作用。现结合我实验室在此方面的工作，对生物技术在水产上的应用做一简要介绍。一、罗非鱼遗传育种目前，最适于我国养殖的罗非鱼品种是奥利亚罗非鱼（雄）与尼罗罗非鱼（雌）的杂交子一代，即奥尼鱼，其雄性率高，生长快。研究已表明杂交鱼雄性率高低与亲本纯度相关，因而培育纯种罗非鱼是发展罗非鱼养殖业的基础。我们…     

吉奥罗非鱼养殖试验

本文通过进行吉奥罗非鱼养殖试验，探讨和验证吉奥罗非鱼所的优良经济性状，并获得了显著的效果。在21．45hm^2的池塘中投放平均体重60g的吉奥罗非鱼鱼种48800尾，经192d养殖，吉奥罗非鱼平均体重为0．948kg/尾（最大体重为1．201kg／尾），吉奥罗非鱼产量为44．98t，平均产量为31．02t／hm^2总产值为32．4万元，获利7．65万元，经济效益显著。试验表明，吉奥罗非鱼集成了吉富罗非鱼生长速度快，奥尼罗非鱼雄性率高、抗病力强等优点，适合于不同地区、不同环境的池塘养殖，推广养殖前景广阔。     

罗非鱼的几种养殖方法

罗非鱼（Tilapia），又称“非洲鲫鱼”，隶属于鲈形目（Perciformes）、丽鱼科（Cichlidae）。它属热带性鱼类，适应性广，生长快，抗病力强，群体产量高，肉味鲜美，无肌间骨刺，适合水产品加工，可在淡水或咸淡水等各种水体中生长，深受养殖生产者、消费者的青睐，已成为国际上引种养殖最广泛的鱼类之一，也是我国水产引进品种中养殖规模最大的品种之一。     

罗非鱼鱼鳞提胶工艺优化研究

正罗非鱼属鲈形目、鲡鱼科、罗非鱼属。罗非鱼是一种中小型鱼,它具有广盐性、杂食性、耐低氧、不耐低温、天然抗病性强、生长快、繁殖性强等特性,具有很高的养殖经济效益。我国养殖的罗非鱼品种主要有尼罗罗非鱼、奥利亚罗非鱼、莫桑比克罗非鱼以及各种组合的杂交后代等,其养殖主要分布在广东、广西、福建、海南及云南等地区。近年来,我国罗非     

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.     

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.     

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.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.     

Nutritional regulation of hepatocyte fatty acid desaturation and polyunsaturated fatty acid composition in zebrafish (Danio rerio) and tilapia (Oreochromis niloticus)

The desaturation and elongation of [1-¹⁴C]18:3n-3 was investigated in hepatocytes of the tropical warm freshwater species, zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus). The hepatocyte fatty acid desaturation/elongation pathway was assayed before and after the fish were fed two experimental diets, a control diet containing fish oil (FO) and a diet containing vegetable oil (VO; a blend of olive, linseed and high oleic acid sunflower oils) for 10 weeks. The VO diet was formulated to provide 1% each of 18:2n-6 and 18:3n-3, and so satisfy the possible EFA requirements of zebrafish and tilapia. At the end of the dietary trial, the lipid and fatty acid composition was determined in whole zebrafish, and liver, white muscle and brain of tilapia. Both zebrafish and tilapia expressed a hepatocyte fatty acid desaturation/elongation pattern consistent with them being freshwater and planktonivorous fish. The data also showed that hepatic fatty acid desaturation/elongation was nutritionally regulated with the activities being higher in fish fed the VO diet compared to fish fed the FO diet. In zebrafish, the main effect of the VO diet was increased fatty acid Δ6 desaturase activity resulting in the production of significantly more 18:4n-3 compared to fish fed the FO diet. In tilapia, all activities in the pathway were greater in fish fed the VO diet resulting in increased amounts of all fatty acids in the pathway, but primarily eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). However, the fatty acid compositional data indicated that despite increased activity, desaturation of 18:3n-3 was insufficient to maintain tissue proportions of EPA and DHA in fish fed the VO diet at the same level as in fish fed the FO diet. Practically, these results indicate that manipulation of tilapia diets in commercial culture in response to the declining global fish oil market would have important consequences for fish fatty acid composition and the health of consumers. Scientifically, zebrafish and tilapia, both the subject of active genome mapping projects, could be useful models for studies of lipid and fatty acid metabolism at a molecular biological and genetic level. This revised version was published online in August 2006 with corrections to the Cover Date.     

Production of diatom–bacteria biofilm isolated from Seriola lalandi cultures for aquaculture application

Controlled incorporation of selected microalgae and bacteria in aquaculture systems can be beneficial because they can act as microbiological control. That is why the characteristics of biofilm generated naturally in Seriola lalandi culture cages were analysed, their potential benefit to the growth of larvae was studied, and their controlled use for improving the larval viability and as a vector to improve incorporation of previously studied probiotic bacteria was tested. According to biodiversity results, these biofilms are composed of a diatom–bacteria mix showing a decrease in biodiversity in laboratory culture conditions being dominated by Navicula phyllepta and bacteria of the family Rhodobacteraceae. This can be produced on mesh substrates incorporated in bioreactors with rapid growth rate and adhesiveness. Preliminary results from the addition of substrates with this specific biofilm in larvae culture systems showed that it is consumed by the larvae without negative effects, while positive effects on the viability of larvae in combination with probiotics were observed. Considering preliminary results, the addition of these specific substrates with diatom–bacteria biofilms could be a good improvement for aquaculture systems and together with the use of probiotics can contribute to maintaining a stable and controlled system improving the viability of the larval fish culture in its early stages.