Chemical Composition and Bioactivity of Lippia adoensis Hochst ex. Walp (Verneneaceae) Leaf Essential Oil Against Callosobruchus maculatus Fabricius (Coleoptera：Chrysomelidae)

Essential oil(EO) of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry(GCMS) and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol(28.36%), α-Terpineol(25.99%), γ-Terpinene(15.24%), α-Pinene(5.08%), 1H-Cyclopropa[a]naphthalene(4.25%) and 1, 3, 6, 10-Dodecatetraene(3.74%). Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment(HAT), application of L. adoensis leaf EO at 107 μL· L~(-1) air caused significantly(p?0.05) higher mortality(50.00%) than 0.00% mortality observed at 0-53 μL· L~(-1) air, but not significantly(p?0.05) different from 22.50% observed in 80 μL· L~(-1) air. At 3 HAT, application of L. adoensis EO at 80 μL· L~(-1)air caused significantly higher mortality(90.00 %) than mortality observed at 0 μL· L~(-1) air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L~(-1) air caused significantly higher mortality(100.00 %) than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L~(-1) air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly(p0.05) affected by doses. Application of EO at 10-30 μL· cm~(-2) caused class V repellence(86.67%-100%) compared with the control which caused class I repellence(0-20%).     

Cultivation of whitebait (Galaxias maculatus) in Chile

The growth of commercial aquaculture in Chile generated an income of $2.300 million USD in exports in 2005. Currently, 15 different species are cultivated commercially, of which seven are native; these had returns of 185 million USD. Among these native species is Galaxias maculatus (whitebait), which is endemic to Chile and figures significantly in Chilean fishing statistics. Since the 1990s, the School of Aquaculture of the Universidad Catolica de Temuco has been developing cultivation of this native species. This work presents the state of the art of the cultivation of this fish.     

鲈鱼白细胞介素-8 cDNA序列的克隆与原核表达

采用RT-PCR方法扩增和克隆了鲈鱼白细胞介素-8(LjIL-8)的编码阅读框。该编码阅读框由300个核苷酸组成,编码由99个氨基酸组成前体蛋白。LjIL-8氨基酸序列与哺乳动物和鱼类IL-8类似物的氨基酸同源性分别为23%~48%和25%~92%。氨基酸序列分析表明,N端存在一长23个氨基酸的信号肽,含有形成2个链内二硫键的4个半胱氨酸。分子进化分析表明,LjIL-8与欧洲鲈鱼的亲缘关系最近。将LjIL-8编码序列克隆到原核表达载体pET-28a (+),转化E.coli BL21(DE3)后用IPTG进行诱导表达,SDS-PAGE检测结果表明,预期分子量大小的小分子蛋白在大肠杆菌中成功表达,Western-blotting检测结果显示,目的蛋白能与抗6×His单克隆抗体发生特异性反应。     

饥饿及恢复投饵过程中花鲈肌肉组成及非特异免疫水平的变化

探讨了饥饿及恢复投饵过程中花鲈（Lateolabrax japonicus）（196±38g）肌肉组成分及鱼体非特异免疫水平的变化。实验设S0组（对照组，持续正常投喂），S5组（饥饿5d后恢复正常投喂），S10组（饥饿10d后恢复正常投喂），S15组（饥饿15d后恢复正常投喂）。S0组每隔5d取样，S5，S10和S15组分别在结束饥饿及恢复投饵后每隔5d取样测定。结果显示：饥饿程度对花鲈肌肉组成有显著影响。与对照组相比，S10组饥饿结束时肌肉的总脂含量显著降低；S15组饥饿结束时肌肉的总脂含量和粗蛋白含量都显著降，同时显著增加了肌肉的水分含量。表明饥饿过程中花鲈先动用肌肉脂肪，后动用肌肉蛋白。在恢复投饵过程中，S10和S15组总脂含量表现出先降后升的规律，而S15组蛋白表现为逐步回升的趋势。表明花鲈在饥饿后恢复投饵的过程中，先恢复肌肉蛋白含量，后恢复肌肉脂肪含量。饥饿15d时花鲈血清蛋白浓度显著降低。与对照组相比，S5组血清、脾脏和头肾溶菌酶活性均无显著变化；S10组头肾溶菌酶活性在恢复投饵10d时补偿性升高。S15组在饥饿结束时显著降低了花鲈头肾溶菌酶活性，但在恢复投饵5d时恢复到对照组水平。花鲈白细胞的吞噬活性也受饥饿程度及恢复投饵的影响。饥饿会降低花鲈血液白细胞的吞噬活性。在恢复投饵过程中,饥饿（5d）后恢复投饵会引起白细胞吞噬百分率和吞噬指数的补偿性升高。表明饥饿及恢复投饵也影响花鲈的非特异免疫水平。     

Evaluation of powdered fruits of four peppers (Capsicum spp.) for the control of Callosobruchus maculatus (F) on stored cowpea seed

Abstract

The efficacy of two application rates of powdered fruits of four types of peppers (Capsicum spp.) was evaluated for the control of Callosobruchus maculatus (F). The various pepper powders at 2.5 g‐5.0 g per 250 g of seed were effective in reducing oviposition and damage to cowpea seeds. The pepper type Capsicum frutescens var. yarmunchi was the most effective in discouraging oviposition and minimizing damage to the seed, as indicated by the significantly lower number of emergence holes. The seed quality and viability were not affected by the powdered pepper fruit treatment. The result is indicative of the potential for the use of powdered fruits of some peppertypes in protecting stored cowpea seeds against C. maculatus.     

Growth-dependent survival mechanisms during the early life of a temperate seabass (Lateolabrax japonicus): field test of the ‘growth–mortality’ hypothesis

Three concepts based on size, time and growth rate are contained in the functional mechanisms of the ‘growth–mortality’ hypothesis, and are known as the ‘bigger is better’, ‘stage duration’ and ‘growth-selective predation’ hypotheses, respectively. Although it is sufficiently documented in fishes that faster growing and bigger larvae selectively survive, synergistic operation of the three components of the ‘growth–mortality’ hypothesis within a species have received little attention. In this study, we have tested the components of the ‘growth–mortality’ hypothesis based on the growth characteristics of original population (OP) and survivors (SV) of Japanese seabass (JSB) Lateolabrax japonicus. Larval and juvenile JSB were repeatedly sampled from the Tango Sea in 2007 and 2008. Otoliths from larvae and juveniles were analyzed to produce back-calculated daily records of size-at-age and growth rate, and were compared between OP and SV. Selective survival for fast-growing and bigger larvae was evident, and our results strongly support the ‘bigger is better’ hypothesis as well as the ‘growth-selective predation’ hypothesis. Growth rates of the individuals that metamorphosed into juveniles had significantly faster growth rates than non-metamorphosing larvae older than 48 days, the minimum age for metamorphosis, suggesting a clear relationship between growth rates and the timing of metamorphosis. On average, SV completed the larval stage ∼13 days earlier than those of OP, supporting the ‘stage duration’ hypothesis. Thus, SV of JSB exhibited traits consistent with all aspects of the ‘growth–mortality’ hypothesis: faster growth, bigger size-at-age, and shorter larval stage duration (LSD), i.e., larvae with faster growth, bigger size-at-age and a shorter LSD selectively survived the larval period. Although maternal influence on growth and survival was evident, factors that regulate growth–mortality mechanisms remain to be explored for JSB.     

RseB影响溶藻弧菌感染花鲈的能力

为了研究Rse基因缺失对溶藻弧菌感染花鲈能力的影响，评估了花鲈感染后的LD50、定殖能力和免疫响应，结果显示，溶藻弧菌野生株LD50为2.013×105CFU/ml，RseB缺失溶藻弧菌LD50为5.526×105CFU/ml，RseB缺失溶藻弧菌毒力下降2.75倍；溶藻弧菌主要在花鲈的鳃部、肠道、皮肤定殖，RseB缺失溶藻弧菌定殖肠空泡化程度更低，鳃组织结构的损坏程度更低；分别对野生株与RseB缺失溶藻弧菌感染的花鲈头肾组织进行转录组测序，发现与免疫相关的差异表达基因一共有236个，其中包括了122个显著上调的免疫基因和114个显著下调的免疫基因，这些基因大部分显著富集在Th1和Th2细胞分化、B细胞受体信号通路、T细胞受体信号通路等特异性免疫通路上，部分基因显著富集在与细胞凋亡相关的通路以及与炎症相关的NF-kappa B信号通路中。综上结果表明RseB缺失溶藻弧菌能引起宿主细胞的免疫反应且毒力有所降低。     

盐度与碱度对花鲈幼鱼的毒性研究

试验研究盐度与碱度对花鲈(Lateolabraxjaponicus)幼鱼的急性毒性结果表明,24h、48h、72h、96h碱度对花鲈幼鱼的半致死浓度(LC50)分别为101.05mmol/L、63.27mmol/L、56.85mmol/L和46.18mmol/L;盐度和碱度联合毒性试验结果显示碱度对花鲈幼鱼24h半致死浓度与盐度显著相关,二者间关系为ALK=125.05-2.18S(n=7,r=0.9756),表明盐度和碱度之间可能存在一定的交互作用。     

不同盐度条件下饥饿及恢复摄食鲈稚鱼脂肪酸的组成

采用气相色谱法测定和分析了15.00、7.50及淡水3个盐度条件下鲈稚鱼在饥饿时及其恢复摄食后的脂肪酸变化。结果显示,在3个盐度条件下,饥饿的鲈稚鱼均首先消耗饱和脂肪酸,随后才会消耗不饱和脂肪酸;恢复摄食后的鲈稚鱼,其不饱和脂肪酸也优先得到补充。在3个盐度条件下,以淡水组饥饿稚鱼的多不饱和脂肪酸的消耗量最大,但在恢复摄食后,其EPA、DHA的含量又为最高,这可能与不同盐度条件下鲈稚鱼的生物转化能力不同有关。