稻田与池塘养殖瓯江彩鲤肌肉营养成分对比分析

为探究不同养殖条件下瓯江彩鲤肌肉营养组成的差异,分别对吉林省稻田养殖(PF组)和池塘养殖(PC组)瓯江彩鲤肌肉的常规营养成分、氨基酸、脂肪酸以及部分矿物元素含量进行测定,分析了两种养殖条件下瓯江彩鲤营养组成的差异。就常规营养组成而言,PF组瓯江彩鲤肌肉中水分含量显著高于PC组(P<0.05)。PF组瓯江彩鲤肌肉中甘氨酸(Gly)、酪氨酸(Tyr)及胱氨酸(Cys)等氨基酸的含量均显著高于PC组(P<0.05),且PF组鲜味氨基酸总量明显高于PC组;就脂肪酸组成而言,PF组瓯江彩鲤肌肉中二十碳五烯酸(EPA)和二十二碳六烯酸甲酯(DHA)含量均显著高于PC组(P<0.05);除镁(Mg)和钠(Na)外,PF组瓯江彩鲤肌肉中其余矿物元素含量均显著高于PC组(P<0.05)。综合肌肉氨基酸组成、脂肪酸组成及矿物质含量等结果,稻田养殖瓯江彩鲤的营养品质优于池塘养殖个体。     

神经网络在养殖水质精准预测方面的研究进展

目前神经网络研究文献成果较多,虽然在水质精准预测方面起到了一定的参考,但由于文献缺少科学分类,使用率不高,导致学者难以找到研究切入点。针对这一问题,本文将神经网络方法在养殖区水质精准预测方面的文献按照海水和淡水两大领域进行分类,主要对每个领域所应用的预测模型从正反馈架构、循环架构和混合架构三个方向对海水时空序列文献进行分类研究和综述,发现混合架构模型的预测性能优于正反馈模型和循环架构模型,有利于提升不同深度水质预测模型的精度。另外,本文对基于神经网络方法的三维水质预测模型进行了初步探讨,发现学者的研究成果更多地集中在水表层和水中层的不同位置水质参数的变化方面,而神经网络方法对水表层水质预测精度比水中层和水深层水质预测精度高。     

Ecological and eco‐social models for the introduction of the abalone Haliotis discus hannai into benthic systems of north‐central Chile: sustainability assessment

• 1. Loop models of ecological and socio‐economic systems were developed to analyse and predict the impact of a possible accidental introduction (escapes) of the abalone Haliotis discus hannai into a benthic community of north‐central Chile.
• 2. Although the ‘new’ ecological system resulting from a successful invasion of abalone would be locally stable, the establishment of a self‐enhanced dynamic of recruits would transform this into an unstable system.
• 3. The harvest of the kelp, Lessonia trabeculata and other macroalgae is not recommended because this destabilizes the system. The harvest of abalone adults is only sustainable if they do not exert a negative effect upon other native invertebrates.
• 4. The eco‐social model showed three important results: (1) if the variables ‘Price’ and ‘Farming’ are in expansion and stationary dynamics, then the models were found unstable; (2) a self‐enhanced dynamic of abalone recruits tends toward instability; and (3) the harvest of the kelp L. trabeculata and other macroalgae would be non‐sustainable.
• 5. Based on our results, the sustainable development of extensive farming of H. discus hannai in the sea would be not reached. If it is done, an intensive monitoring of the community after introduction into the system is strongly recommended. Likewise, the farming of macroalgal species (source of food for abalone) should be promoted in order to avoid harvesting of macroalgae from natural systems.

Copyright © 2006 John Wiley & Sons, Ltd.     

Ornamental Reef Fish Aquaculture and Collection in Hawaii

Ornamental fishes endemic to Hawaii's reefs are a valued resource and a staple of the marine aquarium trade, worldwide. At present, the market for Hawaiian ornamental reef fish is supplied entirely by the export of wild-captured animals, but the long-term sustainability of this practice is debatable. The success of breeders of ornamental fishes elsewhere, and concerns about overexploitation of wild fishes have stimulated interest in the development of an industry based on the captive propagation and rearing of Hawaiian ornamental fishes. Initial attempts to spawn and rear the larvae of various marine ornamental fishes in Hawaii were carried out in the early 1970s. The results of these culture efforts, conducted primarily at the Oceanic Institute and the University of Hawaii's Hawaii Institute of Marine Biology on Oahu, have varied in success. For the most part, these results have appeared previously only in dissertations or in reports distributed locally. Technological improvements in marine aquarium husbandry and in the culture of edible marine fishes have both benefited practitioners of ornamental reef fish culture, and promise to do so in the future. Our objective in this paper is to review the progress that has been made in the captive cultivation of ornamental marine fishes and to provide an overview of the status of the marine aquarium industry in Hawaii.     

Experimental rearing of juvenile New Zealand turbot Colistium nudipinnis (Waite 1910): a potential new aquaculture species

Investigations into factors affecting the growth of the first hatchery-produced juvenile New Zealand turbot Colistium nudipinnis (Waite 1910) showed that this endemic flatfish can be reared in raceways and tanks. After initial high mortality (> 60%) in the post-weaning period (to 120 days post-hatch), the juveniles showed high survival over the grow-out period. Growth of the juveniles was better at lower (16–18 °C) than at higher (> 20 °C) water temperatures, and better in a deep tank than in shallow raceways. Under the experimental rearing conditions, growth (to mean weight of 0.2 kg in 20 months) was relatively slow and food conversion (FCRs > 1.4) relatively high, both factors being related to the feeding behaviour of this species. C. nudipinnis feeds directly from the bottom, and this behavioural characteristic influences aspects of fish farming practice, such as stocking density and feeding strategy, that are critical to its economic viability. There is potential to improve the growth by optimizing the rearing conditions, so that it may not be unrealistic to achieve the maximum growth reached in these trials commercially and produce marketable farmed turbot, of over 400 g weight, within 2 years.     

对虾工厂化养殖中浮游动物群落结构的变化规律

为了掌握对虾工厂化养殖过程中浮游动物的变动规律,有效管理水体环境质量,提高养殖效益,于2018年8月17日~11月3日,以凡纳滨对虾(Litopenaeus vannamei)为研究对象,分析了对虾工厂化养殖水体中浮游动物群落结构特征、演替规律及其与养殖水体弧菌、浮游微藻和环境因素的关系。结果显示,从实验塘鉴定出21种浮游动物,隶属于4大类,种类最多的为原生动物,共13种,占总数的61.9%;其次为轮虫和桡足类,均为3种,占总数的14.3%;枝角类最少,占总数的5%。整个养殖期,浮游动物的平均密度约为0.71×103 ind./L,平均生物量约为11.72 mg/L。养殖过程中优势种由原生动物、轮虫、桡足类物种逐渐演变成单一的原生动物物种。实验塘浮游动物Shannon-Wiener多样性指数(H′)在0.52~1.64之间波动,前期先降低后升高,后期有所降低。相关性分析显示,浮游动物数量和浮游微藻数量显著负相关(P<0.05),典范对应分析(Canonical correspondence analysis, CCA)显示,温度、pH、营养盐等是影响浮游动物优势种演替的重要因素。研究结果为深入认识凡纳滨对虾工厂化养殖中浮游动物的群落结构提供了基础数据。     

生物—电氧化法去除海水养殖循环水污染物

为提高海水养殖循环水处理效率,降低处理成本,本研究采用曝气生物滤器与电化学阳极氧化组合工艺,考察了不同阳极电势、进水氨氮和亚硝酸盐浓度下系统对氨氮及亚硝酸盐等污染物的去除效果,研究了微生物与工作电极之间的相互作用,并分析了电化学反应能耗。在水力停留时间为45 min、1.4 V阳极电压、进水氨氮和亚硝酸盐浓度分别为4.5和1.3 mg/L条件下,生物—电氧化法对氨氮去除率达88.8%,高出对照组7.6%,出水氨氮和亚硝酸盐浓度分别为0.5和0.9 mg/L,COD去除率为88.2%,高出对照组19.4%,平均能耗0.040 kWh/m³,电极表面微生物生长对阳极电氧化过程有促进作用,微生物功能预测显示实验组硝化功能占比为0.03%,对照组为0.07%。研究表明,生物—电氧化法对海水养殖循环水的污染物有良好的去除效果,具有一定的发展应用潜力。     

Comparative survival and growth performance of European lobster Homarus gammarus post‐larva reared on novel feeds

One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by‐products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post‐larval lobsters from post‐larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze‐dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven‐dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring‐based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non‐heat‐treated shrimp products are a promising feed ingredient for post‐larval European lobsters.     

Increase in milt production by hormonal treatment in the pejerrey fish Odontesthes bonariensis (Valenciennes 1835)

In spite of interest in the cultivation of the pejerrey fish Odontesthes bonariensis (Cuvier & Valenciennes 1835), there are few studies on subjects required to advance this activity. One of the problems is the synchronization of female and male maturation to provide eggs and sperm for larval production. The low volume of expressible milt, either in wild or culture fish, is a major problem. The aim of this work was to study the effectiveness of the administration of different hormones on sperm production in pejerrey. Milt production was enhanced by the injection of human chorionic gonadotropin (hCG) (16.7‐fold increase, 625 IU kg^?1), carp pituitary extracts (13.5‐fold increase, 30 mg kg^?1), salmon pituitary extracts (12.8‐fold increase, 30 mg kg^?1), salmon‐type gonadotropin‐releasing hormone analogue (GnRH) (16.7‐fold increase, 10 μg kg^?1) and mammalian‐type GnRH analogue (10.8‐fold increase, 20 μg kg^?1). Sperm concentration, motility and the fertilization rate were not statistically different compared with control groups. It was also demonstrated that sperm could be obtained off‐season. Taken together, hCG is recommended to stimulate pejerrey spermiation because it is effective in low doses is inexpensive and is widely available.     

Beneficial properties of lactic acid bacteria isolated from a Rana catesbeiana hatchery

This work addresses the selection of potentially probiotic lactic acid bacteria (LAB) to be used in raniculture. Thus, strains belonging to the genera Pediococcus pentosaceus, Leuconostoc mesenteroides, Lactococcus lactis and Enterococcus faecium isolated from a Rana catesbeiana hatchery were evaluated for their inhibitory properties against RLS-associated pathogens ( Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus epidermidis ) and food-borne bacteria. Cell-free supernatants of LAB strains inhibited the growth of at least one of the pathogens by organic acids, but L. lactis CRL 1584 also produced a bacteriocin-like metabolite. The ability of LAB strains to produce H₂O₂ in MRS+TMB medium was also studied. Seventy-eight to ninety six per cent of the strains showed some level of H₂O₂ production. Moreover, different organic solvents were used to determine the hydrophobicity and Lewis acid/base characteristic of LAB strain surfaces. Most of the strains presented hydrophilic properties, but no acidic or basic surface characters. However, some strains isolated from the skin showed a high degree of hydrophobicity and basic components in the cell surface due to their adhesion to chloroform. These properties were not observed in LAB from balanced feed and freshwater. Taking into account general guidelines and the beneficial properties studied, five strains were selected as potential candidates to be included in a probiotic for raniculture.