中草药用于水产养殖病害防治的研究与应用

中草药是中药和草药的总称，水产养殖使用的中草药称为渔用中草药，主要指在中医理论指导下用于防治疾病、促进健康、提高生产性能和养殖动物产品质量的天然物质，包括植物性、动物性及矿物性中草药。中草药用于水产养殖病害防治已有悠久的历史，特别是淡水鱼养殖，中草药的使用已经比较广泛。中草药具有天然性、     

鱼病防治除虫为先

鱼病防治是水产养殖中的重要环节,抓好鱼病防治,对于提高产量,增加效益极为重要.要搞好鱼病防治,第一个环节就是要杀灭鱼体上和水体中的寄生虫.     

微生物在水产养殖中的应用

从四个方面论述了微生物在水产养殖中的应用，微生物饲喂水产动物，微生物用于水产动物疾病的防治，微生态制剂的应用和微生物改良水质，简单介绍了微生物溶藻，微生物诱贝类附着和工程菌应用于水产养殖的新进展。     

中草药在水产病害防治中的应用

<正>目前,中草药在水产病害防治中的应用比较广泛,尤其在淡水养殖中,更是取得了很大的成效。本文结合笔者的工作经验,主要分析了中草药的重要成分以及在水产病害防治中的实际应用。一、中草药介绍中草药,即是中药和草药的合称。在水产养殖中使用的中草药被称之为渔用中草药,主要是在中医理论的指导下用于防治水产动物的疾病,以达到最终促进生产和提高动物产品质量的目的。同时,中草药还具有无抗药性和药物残     

黄鳝网箱养殖技术及其病害防治

黄鳝是淡水鱼类中的佳品,由于野生自然资源日趋减少,黄鳝的人工养殖经济效益较高,前景看好.近年来,随着水产养殖结构的调整,在池塘中设置网箱养殖黄鳝模式得到广范推广.为有效地提高黄鳝养殖产量和效益,促进黄鳝养殖健康发展,现将池塘网箱养殖黄鳝的技术及其病害防治方法介绍如下,仅供广大养殖户参考.     

鱼病防治应注意的事项

鱼病防治是渔业生产中的关键环节,直接关系到渔业养殖的效益的高低。在养殖生产中,许多养殖单位及养殖户不注意鱼病防治,随意乱用药,给生产带来不必要的损失。鱼病防治应注意以下事项：     

中草药在水产养殖中的应用

中草药用于水产养殖及病害防治历史悠久,中草药在水产养殖中起到：诱食、增加机体免疫力、杀菌驱虫抗病毒等作用,且具有无毒、无残留、无抗药性等特点,在水产无公害健康养殖过程中日益广泛应用。     

生石灰在水产养殖中应用及评价

水产养殖的成功离不开对疾病的有效防治，对水产疾病的防治，必须从清塘消毒和池水消毒做起。而养殖户常用于清塘消毒和池水消毒药物是生石灰。所以笔者认为有必要重新认识和评价生石灰“在水产养殖中应用。土石灰有效成分是氧化钙（CaO），易溶于水，生成熟石灰即氢氧化钙，呈碱性，pH值11－12。经过水产养殖户的长期实践，证明生石灰是水产业中用于改善水质、防治疾病必不可少的药物。具体总结、分析如下。1在水产养殖中的作用1.1水体清洁作用生石灰通过中和水中酸性物质和结合作用，使悬浮胶状有机杂质、泥末胶结和吸附沉底，从而澄清…     

斑点叉尾鮰疾病及防治

斑点叉尾鮰的鱼病防治是养殖过程中的一个重要环节,尤其在高密度养殖中更为重要,应切实做好防病治病工作,落实"无病先防、有病早治、防重于治"的方针.     

关于水产养殖病害防治问题探讨

随着生活水平的不断提高,人们对于水产品的需求越来越高,同时大量的工业废水与废料、生活垃圾等等都严重污染了水产养殖的环境,给水产养殖带来相当大的问题.本文针对水产养殖中的病害防治问题展开讨论,希望对水产养殖事业提供一定的帮助.     

A review of the use of ivermectin as a treatment for sea lice [Lepeophtheirus salmonis (Krøyer) and Caligus elongatus Nordmann] infestation in farmed Atlantic salmon (Salmo salar L.)

Ectoparasitic sea lice, Lepeophtheirus salmonis (Krøyer) and Caligus elongatus (Nordmann) browse on the skin of farmed Atlantic salmon, Salmo salar L.. The resulting lesions cause stress and increase the susceptibility of the fish to secondary infections. In extreme infestations, fish can suffer from osmoregulatory failure and death. The most immediate treatment for the relief of sea lice infestations at fish farms is the use of chemotherapeutants, either by bath or oral administration. One compound which has been investigated for use as a chemotherapeutant is ivermectin. Ivermectin is a member of the avermectin group of macrocyclic lactones. The avermectins are neurotoxins, which have been used successfully in the treatment of helminthic parasitic infections in a number of terrestrial farm animals and also in the treatment of river blindness in humans. Owing to the low solubility of the compound, ivermectin has been administered as an oral treatment with the feed and has been found to be effective for the treatment of sea lice on Atlantic salmon. Ivermectin is poorly absorbed by fish with a high percentage of the administered dose being excreted in the faeces. The highest concentrations of the absorbed ivermectin were found in lipid‐rich organs. The ivermectin remained in the tissues of the treated fish for a prolonged period of time and was excreted mainly in the unchanged form. Ivermectin can reach the marine environment via excretion from the bile, unabsorbed via the fish faeces and by uneaten food pellets and has a strong affinity to lipid, soil and organic matter. Risk assessments have shown that ivermectin is likely to accumulate in the sediments and that the species therein would be more at risk than the species in the pelagic environment. Ivermectin has been shown to be toxic to some benthic infaunal species in single species tests, but there is no evidence that treatment of fish with ivermectin has affected multispecies benthic communities in the field situation. This review paper ends with details of the development and the status of the use of ivermectin in the treatment of sea lice infestations at Scottish fish farms.     

Toxicity of intraperitoneally injected ivermectin in sea bream, Sparus aurata

Ivermectin has been widely used as a treatment against sea lice infections of farmed fish (salmonids and non-salmonids) without any official license for use in aquaculture. This study presents data on the toxic side effects of ivermectin administered intraperitoneally in sea bream, Sparus aurata at single doses of 100, 200, 400 and 800 μg ivermectin kg⁻¹ fish. The toxicity of ivermectin was evaluated for a period of 35 days post treatment by determining changes in selected hematological parameters (hematocrit, hemoglobin, red blood cell count, leucocyte count, differential white blood cell count, plasma glucose, electrolytes, urea and alkaline phosphatase), pathological effects in the tissues and the organs of the fish using histological techniques and changes in the behavior of the fish. The results showed a decrease of the hematocrit value one hour after the injection for most of the doses along with an increase of the hemoglobin concentration, the number of the white blood cells, the lymphocytes and monocytes and plasma glucose. No mortality or any histopathological alteration at the tissues examined, were recorded. The fish, which were injected with the highest dose of ivermectin, experienced a loss of appetite, lethargy and darkening of their color during the first week post injection. All the studied parameters reached the normal level by the end of the experiment indicating a low and reversible toxicity of the drug. This revised version was published online in August 2006 with corrections to the Cover Date.     

Escape-related behavior and coping ability of sea bream due to food supply

Escape of fish is a significant problem for the sustainability of the aquaculture industry. In the Mediterranean Sea, sea bream (Sparus aurata) has been reported to escape from sea cage installations. However, the related factors leading to this behavior still remain unknown. This study focuses on the impact that the food supplied to sea bream has on its interaction with the net and therefore its escape behavior. We test three food ratios (2, 1 and 0?% of the total initial body weight; FC2, FC1 and FC0 populations, respectively) and three different conditions of the net (flawless mesh, mesh with a cut twine and mesh with a tear) that are commonly found in aquaculture. Data acquisition and analysis are carried out with a tailor-made system developed in our laboratory for this purpose. We demonstrate that food supply is associated with fish interactions and the aquaculture net, while net condition is also an important stimulus for sea bream inspection and biting the net. Limited-fed fish (FC1) are more prone to interact with the net, which consequently leads them to either bite net wears or escape through tears.     

Water temperature,time of exposure and population density are key parameters in Enteromyxum leei fish-to-fish experimental transmission

Enteromyxum leei is a myxozoan histozoic parasite that infects the intestine of several teleost fish species. In gilthead sea bream (Sparus aurata), it provokes a chronic disease, entailing anorexia, delayed growth, reduced marketability and mortality. Direct fish-to-fish transmission, relevant in aquaculture conditions, has been demonstrated for E. leei via effluent, cohabitation, and oral and anal routes. However, the minimum time of exposure for infection has not been established, nor the possible effect on the fish immune response. Two effluent trials were performed at different temperatures (high: average of 25.6°C; and low: constant at 18°C), different times of exposure to the effluent (1, 3, 5 and 7 weeks) and different population densities. The results showed that 1 week was enough to infect 100% of fish at high temperature and 58.3% at low temperature. High temperature not only increased the prevalence of infection in posterior intestine, but also induced a higher production of specific antibodies, limiting the progression of the infection along the intestine. Longer time of exposure to the parasite and higher fish densities facilitated E. leei infection. These results show that effective diagnosis, lowering animal density and removal of infected fish are key aspects to manage this disease in aquaculture facilities.     

Betaine supplementation enhances the seawater adaptation of salmon, Salmo salar L.

Abstract. The growth of the Atlantic salmon, Salmo salar L., aquaculture industry has been tremendous; from a modest beginning, today's world production of salmon farming is close to 260 million tonnes in ten different countries. In particular the last 20–30 years have seen a dramatic increase in annual sales and production.
The methods vary. From exploiting the natural migrations of this anadromous fish, sea ranching has produced a viable industry. However, controlling the entire life cycle in closed systems has been more successful.
The growth of the farming industry is seriously hampered by such factors as diseases and parasites, algae blooms, environmental pollution, sabotage and rough seas. Several of these factors will not easily be eliminated, although methodical research and development could make the fish farming industry more efficient. Most of the fish farming is situated in remote regions, and the product has to be transported to heavy populated areas for sale, often across borders. The approximate average production costs per kilo differ according to the organization of the industry, average salary, the feed costs and the industrial hurdles, expressed as loss of fish, due to a variety of factors. Even though the market is growing, we must expect fierce competition. Farms producing fish of high quality at low cost will survive. The industry needs healthy fish in well-run farms, smart farmers and a government which helps the industry with reasonable regulations, guidance, applied and basic research, and insight into the future.     

Effects of Enteromyxum spp. (Myxozoa) infection in the regulation of intestinal E-cadherin: Turbot against gilthead sea bream

Enteromyxoses are relevant diseases for turbot and gilthead sea bream aquaculture. The myxozoan parasites invade the intestinal mucosa, causing a cachectic syndrome associated with intestinal barrier alteration; nonetheless, their pathological impact is different. Turbot infected by Enteromyxum scophthalmi develop more severe intestinal lesions, reaching mortality rates of 100%, whereas in E. leei-infected gilthead sea bream, the disease progresses slowly, and mortality rates are lower. The mechanisms underlying the different pathogenesis are still unclear. We studied the distribution and expression changes of E-cadherin, a highly conserved protein of the adherens junctions, in the intestine of both species by immunohistochemistry and quantitative PCR, using the same immunohistochemical protocol and common primers. The regular immunostaining pattern observed in control fish turned into markedly irregular in parasitized turbot, showing an intense immunoreaction at the host–parasite interface. Nevertheless, E-cadherin gene expression was not significantly modulated in this species. On the contrary, no evident changes in the protein distribution were noticed in gilthead sea bream, whereas a significant gene downregulation occurred in advanced infection. The results contribute to the understanding of the different host–parasite interactions in enteromyxoses. Host and parasite cells appear to establish diverse relationships in these species, which could underlie the different pathological picture.     

Impact of aquatic acoustic noise on oxidative status and some immune parameters in gilthead sea bream Sparus aurata (Linnaeus, 1758) juveniles

This study evaluated the ambient noise effect of onshore and offshore aquaculture systems on oxidative status and on some immune parameters in gilthead sea bream (Sparus aurata) juveniles. The experiment was performed for 40 days, projecting two different playlists of acoustic stimuli: offshore aquaculture noise condition that created the typical acoustic field in proximity of an offshore sea cage for fish farming, using a random sequence of quite sea background and boat noises; and onshore aquaculture noise condition that represented the acoustic field inside an open concrete tank for fish farming. A third group without any acoustic projection was used as a control. After 40 days from the beginning of acoustic noise, fish exposed to the offshore aquaculture condition showed significantly higher levels of total oxidant status, lysozyme activity, antiprotease activity and white blood cells together with a lower albumin/globulin ratio in comparison to fish from the control group; whereas fish exposed to the onshore condition showed analytical data placed between the other groups, though never significantly different. These results demonstrate that the offshore aquaculture noise, and in particular the sea soundscape, adversely influences the oxidative status and the immune function of gilthead sea bream determining a mild stress condition that could affect the sea bream welfare.     

Current research on the use of plant‐derived products in farmed fish

Over the years, aquaculture has shown increasing development in terms of production. However, due to intensive farming practices, infectious diseases represent the main problem in fish farms, causing heavy economic losses. The use of antibiotics for controlling diseases is widely criticized for its negative impact, including selection of antibiotic‐resistant bacterial strains, immunosuppression, environmental pollution and accumulation of chemical residues in fish tissues. On the other hand, though vaccination is the most effective prophylactic method of preventing disease outbreaks, the development of effective formulations is often hindered by high production costs and the antigenic heterogeneity of the microbial strains. Recently, there has been increased interest in the possibility of using medicinal herbs as immunostimulants, capable of enhancing immune responses and disease resistance of cultured fish. Plant‐derived products seem to represent a promising source of bioactive molecules, being at the same time readily available, inexpensive and biocompatible. The aim of this article is to provide an overview of recent research dealing with the use of medicinal plants in aquaculture. Special attention is given to the information about the effects of plant extracts/products on fish growth, haematological profiles, immune responses and resistance to infectious diseases.     

Loop-mediated isothermal amplification: an emerging technology for detection of fish and shellfish pathogens

Fish and shellfish diseases are a constant threat to the sustainability and economic viability of aquaculture. Early diagnosis plays a vital role in management of fish and shellfish diseases. Traditionally, various biochemical and serological tests have been used for fish disease diagnosis. However, the time and expertise required for such diagnoses makes it difficult for aquaculturists to easily adopt them under production conditions. Polymerase chain reaction and probe-based nucleic acid detection have become increasingly popular in fish and shellfish diagnostics. Recently, a novel technique called loop-mediated isothermal amplification (LAMP) has been developed, which is highly sensitive and rapid. LAMP has been used for the detection of bacterial, viral, fungal and parasitic diseases in both animal and plants. In aquaculture, LAMP-based detection of pathogens like Edwardsiella tarda, E. ictaluri, Nocardia seriolae, Tetracapsuloides bryosalmonae, white spot syndrome virus and infectious haematopoietic necrosis virus have been reported. In this review, the application of LAMP for the detection of aquaculture-associated pathogens is discussed.     

The development of the Norwegian wrasse fishery and the use of wrasses as cleaner fish in the salmon aquaculture industry

Norway leads the world aquaculture production of Atlantic salmon Salmo salar and farmed Norwegian Atlantic salmon is currently consumed around the globe. However, sea lice infestation is a major problem faced by the salmon aquaculture industry in Norway and elsewhere. The use of wild-caught cleaner fish, mainly wrasses, has been recommended over the other available methods as the most economical and environmentally friendly option to control sea lice infestation in salmon farming. Here, we review the development of the Norwegian wrasse fishery and the use of wrasses as cleaner fish. In this document, we address the sea lice problem and introduce the main wrasse species employed as cleaner fish, document the cleaning behaviour of wrasses, present the development of a new wrasse fishery associated with the salmon aquaculture industry, and finally, we identify the main challenges associated with the intensive use of wild-caught cleaner wrasses and provide some insight for future directions of the wrasse fishery and further development of aquaculture techniques to supply salmon facilities with domesticated cleaner fish.