日本高密度培养轮虫的现状与展望

对日本高密度培养轮虫Brachionus spp.的方法、原理和技术进行了综述:1)采用浓缩的淡水小球藻作为新食物以取代微绿球藻和面包酵母;2)培养液中充入氧气以防止缺氧;3)自动添加HCI使pH控制在7左右,以促进总氨解离为NH4 和OH-;4)用尼龙滤板清除过量的悬浮有机质;5)加入去泡剂以减少培养液和轮虫被泡沫吸附而流失.采用这些技术可使轮虫培养密度增加到1～2万个/mL,比传统方法提高100倍以上,并大幅度降低了生产成本.最近,日本采用连续的滤膜装置(CMFU)开发了一种新的流水培养系统,其中NH4 和溶解有机质都被滤除,轮虫密度可达到16万个/mL,成功地开发了轮虫的超高密度培养.     

不同饵料培育淡水轮虫试验

依据淡水轮虫的营养需求特性,以豆浆为基础饵料,鱼油、维生素C和维生素E为饵料添加剂,搅拌均匀后投喂。3种添加物质各设定三个水平进行正交试验,共设计9组配方。试验结果表明：黄豆91.9g、鱼油8.0g、维生素C0.1g和维生素E0.0g为最佳饵料配方。     

轮虫生态毒理试验的指标分析

有毒有害化学物质对环境的污染已成为全球性问题，其对水生生物的毒害乃至对生态系统的影响已引起广泛关注。轮虫在水生生态系统中是一个重要的浮游生物种群，其在食物链中的营养传递及水体生态的稳定性方面扮演重要的角色。因此，以轮虫作为模式生物之一进行毒理试验，分析预测各种有毒有害物质和极端环境对水生生物的毒理效应已得到大量的应用。     

Improvement of nutritional quality of live feed for aquaculture: An overview

In hatcheries, the adequate supply of live feed has a vital role in feeding fish larvae, fry and fingerlings. Furthermore, the enhancement of the nutritional quality of live feeds is well‐developed techniques in aquaculture. Essential fatty acids (EFA) such as docosahexaenoic acid (DHA; C22:6 n?3), eicosapentaenoic acid (EPA; 20:5(n?3) and arachidonic acid (ARA; 20:4(n?6) and amino acids are an essential source of proteins for larval rearing of fish. However, the common practised live feeds used for the primary feeding such as rotifers and Artemia are naturally deficient in essential nutrient components. Hence, the improvement of the nutritional quality of live feeds with different oil emulsions and commercial diets, and manipulation of the feed are necessary for fish production. The production protocols of copepods, Moina and fairy shrimps as live feed are still underdeveloped in hatcheries. The different lipid sources using for the enrichment of Artemia and rotifers are not effective on other live feeds, especially copepods and cladocerans (Moina, Daphnia) and fairy shrimps. This review focuses on the importance of live feeds by the techniques of feed enhancement or enrichment of zooplankton by direct incorporation of nutrients for feeding of early stages of fish.     

Incidence of systemic granulomatosis is modulated by the feeding sequence and type of enrichment in meagre (Argyrosomus regius) larvae

Systemic granulomatosis is the most frequent disease in juvenile and adult meagre, but studies regarding the first appearance of granulomas in larvae do not exist. In order to evaluate this, meagre larvae were fed four different feeding regimes as follows: RS and RO (rotifer enriched with Easy DHA Selco or Ori‐Green from 3 to 30 dph respectively), RAS and RAO (rotifer enriched with Easy DHA Selco or Ori‐Green from 3 to 21 dph and Artemia enriched with Easy DHA Selco or Ori‐Green from 12 to 30 dph respectively). All treatments were also fed with commercial microdiet from 20 to 30 dph. At 30 dph weight, length, specific growth rate and survival were significantly higher in Artemia‐fed larvae, regardless of the enrichment. Microscopic first appearance of granulomas was observed in 20 dph larvae fed RS and RO. At 30 dph granulomas and thiobarbituric acid reactive substances (TBARS), values were significantly higher in RS and RO‐fed larvae than in RAS and RAO‐fed larvae. The results showed that granulomas first appeared in meagre larvae at 20 dph when fed rotifers only. Conversely, a reduced appearance of granulomas and lipid peroxidation occurs when Artemia is included in the feeding sequence reinforcing the hypothesis of a nutritional origin of the systemic granulomatosis.     

Providing harpacticoid copepods via floating sieve improves herring (Clupea harengus L.) larval feeding incidence

Harpacticoid copepods are being considered as alternative candidates for live feed in aquaculture, but their benthic affinity may pose problems for pelagic fish larvae. We compared the swimming behaviour and feeding incidence of herring larvae (Clupea harengus) in the presence of harpacticoid copepods (Tachidius discipes) and rotifers (Brachionus plicatilis). Additionally, we provided T. discipes via a floating sieve to improve the prey availability. The comparison was performed at 5 and 10 days post hatch (dph) via 2D‐video observations. Quantitative analyses of larval trajectories allowed the estimation of feeding behaviour through a series of indicators: swimming speed, straightness of trajectories, turning angles and swimming activities (break, sink, slow, normal, fast). The outcomes highlighted that the prey type had no significant effect on swimming speed or straightness of the swimming path. However, at 10 dph directly copepod‐fed larvae spent less time in slow but more time in the normal swimming‐state than rotifer‐fed larvae and larvae fed with Tachidius via sieve. This suggests higher energy expenditure of directly copepod‐fed larvae. Moreover, the feeding incidence was higher in larvae fed with Tachidius via sieve than directly Tachidius‐fed larvae. Thus, providing harpacticoid copepods via a floating sieve can improve the rearing of marine fish larvae.     

长江上游轮虫群落纵向演替研究

2005～2007年在长江上游通天河至重庆江段干支流设60个采样站,2003～2007年在重庆以下至三峡水库坝前水域设33个采样断面进行轮虫调查,结果在长江上游(通天河至重庆)江段共采集到138种(含亚种)轮虫,隶属于2纲、3目、22科、40属;重庆以下至三峡水库坝前共采集到167种轮虫,隶属于2纲、3目、23科、47属;三峡水库蓄水后的第1年、第2年,重庆以下至三峡水库坝前水域轮虫种类数迅速增长,到蓄水后的第3年开始下降.通过不同区域轮虫群落相似性比较,水电开发强度较大的金沙江下游与三峡库区轮虫群落相似性明显高于金沙江上中游江段,表明水电开发对金沙江下游、长江上游宜宾至重庆段轮虫群落产生了较为明显的影响.     

白洋淀河湖系统轮虫群落结构时空动态及与环境因子的关系

2019年4月、6月和9月分别对白洋淀淀区及府河、孝义河和白沟引河3条入淀河流的轮虫群落及水环境因子开展采样调查,探究了白洋淀河湖系统中轮虫群落结构时空动态及其与水环境因子的关系。结果显示,调查期间共检出白洋淀河湖系统轮虫30种,隶属于7科15属,其丰度和生物量年均值分别为(1.43±1.15)×10³ ind.L^-1和(0.67±0.71) mg.L^-1。Jaccard群落相似性系数和NMDS分析综合表明,白洋淀河湖系统轮虫群落组成在季节和区域尺度上相似性均较低。针簇多肢轮虫（Polyarthra trigla）、螺形龟甲轮虫无脊变种（Keratella cochlearis tecta）和异尾轮虫（Trichicerca sp.）是淀区和入淀河流的共同优势种。此外,3条入淀河流的优势种丰度占比均显著高于淀区。除孝义河外,淀区、府河和白沟引河轮虫群落的Shannon-Wiener和Margalef指数均存在显著的季节性差异,且均在夏季最高。生物多样性指数和轮虫营养状态指数（TSIROT）综合指示白洋淀河湖系统为中-重度污染型及中-富营养型。RDA分析表明,营养物质（TN、TP）、透明度（SD）和溶解氧（DO）是影响白洋淀河湖系统轮虫群落结构的重要环境因子。     

轮虫培育池浮游生物种类组成及生物量的研究

所测９个淡水轮虫池和６个混盐水轮虫池的浮游植物生物量,在轮虫发生高峰前期平均分别为１１７．８ｍｇ／Ｌ和１５６．５ｍｇ／Ｌ;在轮虫高峰期平均为３９．０ｍｇ／Ｌ和８２．３ｍｇ／Ｌ,即高峰期浮游植物生物量只为前期的１／３～１／２。在种类组成上,前期均以小球藻、蓝隐藻、小环藻等小型种类为主,高峰期则以衣藻、扁藻等鞭毛藻类及角毛藻、螺旋藻、颤藻等丝状群体占优势。淡水池和混盐水池浮游动物生物量平均分别为６６．