The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture

The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel.     

水产养殖鱼类生长性状研究进展

生长性状是水产养殖鱼类最重要的经济性状之一,对水产养殖业的发展意义重大。通过以不同的养殖鱼类为对象,大量的研究结果表明,鱼类生长主要受环境、基因,以及基因与环境相互作用的影响,具体为:(1)环境是生长性状调控的外因,其对生长的影响一般呈现出剂量效应的规律。温度、光照、营养等主要环境因子的过量和不足均可能对鱼类生长产生不利影响,因此,寻求最优条件是制定最佳养殖环境的终极目标,人为调控多种环境因子在现代水产养殖业中具有重大的应用潜力。(2)基因是生长性状调控的内因,其对生长的影响很大程度上表现出因果效应的关系。某些基因的单碱基核苷酸多样性、基因结构变异、染色体倍性变化,以及转基因等都表现出对鱼类生长产生统计显著性的影响。鉴于生长是多基因控制的复杂数量性状,寻找主效基因并在选育中加以利用是改良生长性状的重要基础。高通量测序技术在生长相关候选基因的筛选以及辅助分子育种方面展现出强大的优势。(3)基因与环境相互作用的影响主要来自基因型对不同环境条件的适应性,具有特异性和复杂性的特点,因此目前对其量化研究非常有限。但在制定大规模商业育种计划之前,考虑基因与环境相互作用具有重要意义。综上所述,充分理解环境、基因,以及基因与环境相互作用对水产养殖鱼类生长的影响能更好地对其生长性状加以利用,从而最大限度地节约养殖成本和发挥生态效益。     

Price and production trends in the marine fish aquaculture in Spain

The Spanish aquaculture sector has undergone a rapid and continuous growth becoming one of the biggest European producers. A wide range of species are farmed and, among them, the sea bass, sea bream and turbot make a significant contribution to the total of the Spanish fish farming output. In this paper, we analyse and predict the medium-term trend of the production and price level for the three leading species previously mentioned. The results obtained show a significant increase in the production of sea bream, sea bass and turbot. The results show also a slight decrease in the sea bream average price, a stable trends for the sea bass and increasing prices for the turbot.     

鳜养殖概况及摄食调控机制研究进展

鳜是我国名贵的淡水经济鱼类,2019年其养殖产量已达33万t。本文从养殖现状、养殖模式及良种选育等方面介绍鳜的养殖概况。同时,鳜摄食习性独特,终生以活鱼为食。养殖生产中,主要以活饵料鱼直接饲喂,这种以鱼养鱼的方式不仅资源利用率低,对环境和资源的破坏也极大。据此,本文从环境因素和饵料性质等方面概述了影响鳜摄食的外在因素,并从摄食感觉器官和摄食调控因子剖析鳜摄食特性的内在因素,这有助于通过人工干预的方式调整鳜的摄食习性,为其转食配合饲料提供必要的支撑。此外,需加强鳜摄食调控机制及营养生理需求特性的研究,实现鳜配合饲料的突破,促进其养殖业的绿色健康发展。     

The reproductive brain in fish

In fish as in other vertebrates, the brain is actively involved in the control of reproduction, first by participating, under the influence of external factors, in the establishment of an appropriate endocrine status, but also by allowing synchronization of the partners by the time of spawning. It is now well established that the pituitary gonadotropic function is controlled by multiple stimulatory and inhibitory factors, originating mainly from the preoptic region and the mediobasal hypothalamus, both target regions for sexual steroids. Little is known about the mechanisms involved in the mediation of external and internal factors, however there is indication that internal factors, such as androgens and melatonin, known to trigger particular behavioural and endocrine responses, act both at the level of neuroendocrine territories, but also on sensorial systems, which are the actual sites of action for external factors. This paper represents an attempt to summarize and integrate the recent literature devoted to the different aspects of the brain as a major participant in the complex endocrine and behavioural mechanisms of reproduction in fish.     

水解鱼蛋白的营养特征及其在水产动物营养饲料中的研究进展

鱼粉短缺是当今水产饲料行业中亟待解决的难题,而水产品加工副产品占水产品的总重量超过60%,因此,充分利用水产品加工副产品,提高其营养价值,是解决鱼粉短缺的重要途径。水解鱼蛋白是水解水产品加工副产品而得到的富含游离氨基酸和不同肽链长度的蛋白寡肽,目前,越来越多的研究证明,其对水产养殖动物的生长性能具有重要的促进作用。本文从水解鱼蛋白的制备、营养特性及水产饲料中的研究和应用方面展开综述,系统论述近年来水解鱼蛋白在水产动物营养相关领域的研究成果,并提出在水产饲料中的进一步研究方向,以期为水解鱼蛋白在水产动物营养学研究及其在水产饲料中的应用提供参考。     

An integrated recirculating aquaculture system (RAS) for land-based fish farming: The effects on water quality and fish production

To mitigate the serious water pollution caused by the rapid expansion of the aquaculture industry in recent years, the development of improved aquaculture systems with more efficient water usage and less environmental impact has become essential. In this study, a land-based recirculating aquaculture system (RAS) was established that consisted of purification units (i.e., a primary biological pond, two parallel horizontal subsurface flow constructed wetlands [CWs], and a long ecological ditch) and 4-5 series-connected recirculating ponds. This system was mainly designed to stock channel catfish (Ictalurus punctatus), fifteen spine stickleback (Spinibarbus sinensis) and yellow catfish (Pelteobagrus fulvidraco), and the culture efficacy was evaluated based on a 2-year field experiment covering two growing seasons. According to the results, the primary biological pond played a role in sedimentation or nutrient retention, although this was not as evident when the CWs were functioning. The water flowing through the wetland system at a hydraulic loading rate (HLR) of 600 mm/day displayed lower values for the temperature, pH, dissolved oxygen (DO), suspended solids, organic matter and nutrients, whereas the electrical conductivity (EC) was higher, suggesting the accumulation of dissolved solids in the system. Due to the recirculation treatment, the trophic status of the recirculating ponds increased gradually along the direction of the flow and was notably lower in comparison to the control. As a result, the fish production responded to the variation of the water quality, which was reflected in the measurements of culture efficacy (final weight, survival rate, SGR and yield). The three main rearing species showed a decreasing trend along the direction of the flow, which was higher compared to the control, whereas an opposite trend was observed for filter-feeding fish. A Pearson correlation analysis revealed that the main culture species were inclined to live in meso- or oligotrophic conditions, and the silver carp adapted to more eutrophic conditions. Because RAS can provide better environmental conditions year-round, the present culture method could be more suitable for species that are sensitive to water quality in typical subtropical areas.     

环境丰容技术在鱼类增养殖中的应用研究进展

近年来,在野生渔业资源持续衰退、水产 养殖规模不断扩大、人们对鱼类福利关注度不断提升等的背景下,环境丰容作为一种全新的技术手段在水产领域受到广泛关注,被认为在野化放流鱼类行为、增加养殖鱼类产量、提升圈养鱼类福利等诸多方面均具有较大的应用潜力。环境丰容是指在增养殖生产中,采用适当方式向圈养或自然水体引入新的环境刺激,提高其异质性和复杂性,从而实现提升鱼类产量、提高鱼类福利、控制鱼类行为、改善鱼类生理目标的环境优化方式。总体来看,国际上围绕环境丰容技术的相关研究结果层出不穷,理论体系不断完善,但国内水产领域的相关研究尚处于起步阶段。本文在简要介绍环境丰容概念和分类基础上,聚焦目前最受关注的物理丰容方式,评述了物理丰容对鱼类打斗行为、生理应激、代谢生长等重要性状和放流后的适应性行为、个体适合度等增殖性状的影响,重点分析了引发研究结果差异的可能原因及其潜在神经可塑性机理,最后探讨了本领域以往研究的不足及今后的研究方向,旨在为我国开展该方面研究提供借鉴,为增养殖苗种高效健康培育与放流鱼类野化训练提供参考。     

生物絮团技术在水产养殖中的应用研究

传统的水产养殖模式所带来的环境污染、资源浪费和病害频发等问题已成为制约我国水产养殖业可持续发展的主要因素。生物絮团技术(BFT)具有净化水质、提高饵料利用率及病害防控等优点,被认为是有望解决上述问题的新型健康生态养殖技术,已在国内外得到一定规模的应用,并获得了良好的经济、社会和生态效益。本文重点介绍了生物絮团的形成与培养、生物絮团的主要影响因素及其在水产养殖中的应用效果。研究认为,BFT能够改良水质、节约养殖用水、降低饲料成本、提高养殖对象存活率、增加养殖产量和效益;将BFT与生物膜技术相结合,能够更有效地维持养殖水体中适宜的生物絮团含量,避免生物絮团的过量沉积,并能提高水质改良及增产增收的应用效果,具有广阔的应用前景。     

The physiology of triploid fish: current knowledge and comparisons with diploid fish

This paper is aimed at underlining the limited knowledge available about the physiology of triploid fishes compared with diploids. Whereas many aspects (induction, detection, growth, resistance to diseases, etc.) in the production and rearing of triploid fishes have widely been developed and described in the literature, other numerous questions of ecophysiology remain in abeyance, and the study of triploid cells physiology is still in its infancy. Triploid fishes can be considered as models worthwhile for physiological investigations not only for the economical stake in relation to the development of triploid fishes rearing, but also for the cytological and molecular features of their tissues and organs. The functional implications of these features have been poorly studied although they are potential areas of applied and/or fundamental studies.     

Comparison of glass eel stages of American eel and speckled worm eel in a northeast Florida estuary

Since 2001, a glass American eel, Anguilla rostrata (Lesueur), survey has been conducted at Guana River Dam, Florida, USA. Although present in earlier samples, glass speckled worm eel, Myrophis punctatus Lütken, were not identified until a large proportion appeared in samples in 2006. To determine whether the species could be separated in historical samples, weight–length relationships were compared between the two species. Then, with data from the full survey period, relationships between catch rate and annual percent contribution of glass speckled worm eel were explored in relation to temperature, water flow and salinity. Glass speckled worm eel were found to weigh significantly less and had distinguishing physical characteristics that could be used for identification. Glass speckled worm eel constituted between 0 and 34% of the catch, with no detectable pattern in timing or abundance among years. In 2006 and 2012, which had the two largest catches of glass speckled worm eel, relationship between nightly catch rate and measured environmental variables was inconsistent, even when measured variables had a similar range in values. It is recommended that south‐eastern, including Gulf of Mexico, USA, states restrict harvest of glass American eel to prevent the incidental capture and exportation of glass speckled worm eel. Efforts should be made to ensure proper species identification in glass eel surveys.     

益生菌在水产养殖中的研究进展

益生菌已被广泛地应用于水产养殖领域,并得到了普遍的认可。作为新型饲料添加剂,益生菌提高了水产品的产量,带来了巨大的经济效益。本文从益生机理、对仔鱼的益生作用、选择和应用要点、安全性以及在海水养殖领域的研究和应用进展五个方面进行了较为详细的综述,以期为益生菌在水产养殖生产中的应用提供全面的理论知识与应用信息。     

基于计算机视觉技术的水产养殖中鱼类行为识别与量化研究进展

鱼类行为与水体环境密切相关,是鱼类生活状况的直接体现,可以通过分析鱼类行为进行更为精准的养殖管理和操作。计算机视觉技术为鱼类行为识别和量化提供了一种非入侵式且稳定性较好的方法,已逐渐广泛用于鱼类行为研究。本文介绍了计算机视觉技术的技术流程,包括图像采集、预处理、运动目标检测与跟踪,并对各个流程进行分类;综述了计算机视觉技术在鱼类游泳、摄食和体色变化等行为识别、量化研究的现状;分析了计算机视觉技术在鱼类行为识别、量化方面的难点及存在的问题,以期为计算机视觉技术在水产养殖监测领域的发展提供参考依据。     

噬菌体在水产养殖业中的研究进展

随着水产养殖业的发展,养殖密度越来越高,细菌性疾病暴发频繁。现如今主流抗菌手段是抗生素,但其大规模且不规范的使用使得细菌耐药性问题越发严重。为了有效防治水产细菌性疾病,加快推进水产养殖业绿色发展,促进产业转型升级,人们亟需寻求新的抗菌手段来缓解当今的局面。噬菌体是一种感染细菌和古细菌的病毒,具有专一性强、不易产生抗性、代谢快、易开发及成本低等优点。在国内外被广泛研究,同时也被应用于多种疾病的防控,其相关产品也获得认可,但其本身存在的限制也不容忽视。本文首先综合介绍了噬菌体治疗的原理和优势,然后对噬菌体治疗在水产养殖动物细菌性疾病中的研究进展进行综述,并对噬菌体治疗现存的困难和应对策略进行讨论,最后在此基础上作出展望,期望能够为后续噬菌体在水产上的应用研究提供参考。     

鱼类精氨酸营养生理研究进展

精氨酸为鱼类的必需氨基酸之一，其在鱼体内参与蛋白质、多胺的合成，促进生长；精氨酸具有促内分泌作用；精氨酸可在体内生成一氧化氮，一氧化氮参与鱼类心血管活动、免疫功能的调节。某些鱼类可能具有自身精氨酸的合成能力。鱼类赖氨酸一精氨酸拮抗存在种问差异。本研究从精氨酸的合成、生理功能、与赖氨酸的关系以及需求量等方面对鱼类精氨酸的营养生理研究进行了综述。[中国水产科学，2006，13（4）：679-685]     

我国主要鱼类杂交种及其养殖状况

杂交是获得新品种的重要途径。迄今,我国进行了大量的鱼类杂交育种研究,其中不少的杂交种经济性状优良,已大规模应用到养殖生产中,取得了显著的经济效益。本文对鲤(Cyprinus carpio)、鲫(Carassius auratus)、罗非鱼(Tilapia)、鲟(Pseudoscaphirhynchu)和鳢(Channa)等我国主要淡水养殖的杂交鱼类品种进行了介绍,综述了他们目前的养殖现状,旨在为鱼类杂交育种研究和杂交种的生产与管理提供参考。