丁鱥鱼胚胎及仔鱼发育的观察

【目的】研究丁鱥鱼在南方较高水温条件下的生长发育情况,解决丁鱥鱼在南方推广养殖中苗种欠缺的瓶颈问题。【方法】对丁鱥亲鱼进行人工繁殖,然后对其胚胎及仔鱼发育过程进行观察记录。【结果】丁鱥鱼催产效应时间11h,受精率为75.3%,孵化率为82.7%,仔鱼成活率59.3%,育成规格为1.5～2.0cm鱼苗20.0万尾。丁鱥鱼受精卵呈卵圆形,大部分呈青灰色,直径0.50～0.77mm,具粘性;在27.0～31.0℃的温度下,受精卵历时1936min发育后孵出,有效积温为908.89℃·h;胚胎发育可划分为6个阶段30个发育时期。刚孵出仔鱼全长3.84～3.87mm,出膜后第3d卵黄囊吸收60%~80%,约有30%仔鱼开口摄食;第4d卵黄囊吸收90%,约有90%仔鱼开口;出膜第5d卵黄囊基本吸收完,但出现少许死鱼苗。【结论】丁鱥鱼适宜在南方进行繁殖及鱼苗培育,水温应稳定在20.0～27.0℃,不宜超过30.0℃,在孵化及鱼苗培育过程中注意清除敌害生物及保持清新水质,并根据水温情况及时投喂开口饵料,提高仔鱼成活率。     

龟纹瓢虫幼虫人工饲料的研究

以蝇蛆和黄粉虫蛹作为外源动物蛋白配制龟纹瓢虫幼虫人工饲料,从初孵幼虫开始饲喂,以幼虫历期、幼虫存活率、蛹历期、羽化率、成虫体重、成虫获得率作为评价指标,对外源动物蛋白的添加形式进行筛选,蝇蛆及黄粉虫蛹脱脂粉饲喂效果均优于其他蛋白形式;在上述结论配方的基础上,以脱脂粉、酵母抽提物、蔗糖和橄榄油为主成分进行L9(34)正交试验,经Duncan's新复极差检验分析,得出两组优化配方:(1)蝇蛆脱脂粉0.50g、酵母抽提物0.25g、蔗糖0.30g、橄榄油0.01g;(2)黄粉虫蛹脱脂粉0.50g、酵母抽提物0.35g、蔗糖0.30g、橄榄油0.02g.验证饲养表明,两组理论优化配方均符合实际.     

Aerial spraying ofBacillus thuringiensis var.kurstaki for the control ofThaumetopoea processionea in Turkey oak woods

Thaumetopoea processionea L. is an important oak defoliator whose outbreaks have become increasingly frequent in Europe and thus have received a great deal of attention from foresters. Field trials were carried out in central Italy (Tuscany) to test the efficacy of aerial spraying ofBacillus thuringiensis var.kurstaki [Btk] in early spring for the control of processionary infestations inQuercus cerris L. woods. The experimental sites were located in a hilly area of 1640 ha witha maximum altitude of 593 m a.s.l. and a yearly mean temperature of 10°C. Turkey oak woods were divided into three areas to be treated with 31.75 BIU ha⁻¹ (2.5l ha⁻¹) on 578 ha, 44.45 BIU ha⁻¹ (3.5l ha⁻¹) on 306 ha and 57.15 BIU ha⁻¹ (4.5l ha⁻¹) on 756 ha, respectively. Five days after treatment, larval mortality was less than 40% in the control plot, but over 60% in the treated areas. Thirteen days after treatment, larval mortality varied from 75.05% to 96.42% in the three treated areas. Surveys conducted 2 months after the treatment showed a strong decline in the number of oak processionary nests in all the treated plots. It was possible to control the pest effectively in turkey oak woods usingBtk at 31.75 BIU ha⁻¹ distributed at ultra-low volume at the time of bud opening when nonurticating larvae were present. http://www.phytoparasitica.org posting March 12, 2008.     

投喂卤虫无节幼体条件下黄颡鱼仔稚鱼生长、存活率、摄食力和体成分的变化

试验分析了投喂卤虫无节幼体条件下黄颡鱼(Pseudogrus fulvidraco)仔稚鱼生长、存活率、摄食力和体成分的变化。随着仔稚鱼的生长和发育,摄食率和胃充塞度逐渐加大,体长大于10 mm的仔鱼,摄食率都在93.3%以上,大多数个体胃充塞度都在3～5级。投喂卤虫无节幼体的黄颡鱼仔稚鱼生长较传统育苗方式生长快,存活率高。体内粗养分、氨基酸与脂肪酸含量都发生相应变化。黄颡鱼淀粉酶、蛋白酶与脂肪酶活性均在1日龄时即可检测到,开口期即5日龄时,3种消化酶比活力均达到较高值,15日龄后消化酶比活力又都降低到较低水平。卤虫无节幼体体内营养物质含量丰富,大小适口,是黄颡鱼仔稚鱼开口摄食的优质生物饵料。     

Model‐based assessment of local‐scale fish larval connectivity in a network of marine protected areas

We assessed by numerical modeling the coastal fish larval dispersion along the southern coast of Mallorca (Balearic Islands, NW Mediterranean) with the objective of determining the factors that contribute to successful recruitment. We assumed that fish larvae dispersal is mainly regulated by physical transport. Currents are mainly wind driven in this area; therefore, changes in wind forcing have a first‐order impact on larval transport. The synoptic wind patterns were systematically analyzed based on self‐organizing map analysis. The wind fields were clustered using a neural network pattern recognition approach into two modes, producing opposite along‐shelf flow. The seasonal changes between spring and summer in the dominance of either mode modulate the along‐shelf circulation, producing flow shifts under some circumstances. This variability in the wind regime was consistent throughout the 10 years analyzed (2000–2009). Using the Princeton Ocean Model (POM) and a particle‐tracking algorithm, we analyzed the effect of wind‐forced currents in the connectivity among near‐shore habitats. We show that, at the spatial scale considered, the coastal morphology and stochastic wind forcing favor local recruitment (mean of 30% self‐recruitment). Maximum transport distances of 20–30 km were typically associated with particles left to drift for 21 days. The implications for the performance of the four marine protected areas near SW Mallorca Island are discussed. Our results suggest that, although wind episodes determine the fate of short‐time spawning events, on a seasonal basis, regular larval supply to coastal zones is ensured by wind stochasticity.     

Antibacterial activity in microalgae cultures

Five cultures of microalgae (Chlorella minutissima, Tetraselmis chui, Nannochloropsis sp., Arthrospira platensis and Isochrysis sp.) with no culturable bacteria were tested for their ability to inhibit the growth of six Vibrio bacterial strains (V. parahaemolyticus, V. anguillarum, V. splendidus, V. scophthalmi, V. alginolyticus and V. lentus). The influence of light on the antibacterial activity of the microalgae was investigated. All microalgae cultures inhibited the growth of bacteria compared with the control treatments (P < 0.05), and their antibacterial activity was not influenced by the presence or absence of light. In the control groups, the numbers of bacteria increased exponentially during the experimental period in the absence of microalgae cells demonstrating that the bacterial cells were able to utilize the growth medium of microalgae cultures. The present results may explain the low levels or absence of Vibrio strains in microalgae cultures, and the positive effect of addition of microalgae in rearing of fish larvae, and implicate the production of antibacterial compounds by microalgae cells.     

不同饵料对3种西藏鱼类仔鱼生长及存活的影响

研究了卤虫无节幼体、专用仔鱼料、鳗鱼仔鱼料等3种不同饵料对西藏尖裸鲤(Oxygymnocypris stewartii)、异齿裂腹鱼(Schizothorax o'connori Lloyd)、拉萨裂腹鱼(Schizothorax waltoni Regan)等3种鱼类仔鱼生长和存活的影响。实验尖裸鲤、异齿裂腹鱼、拉萨裂腹鱼仔鱼的初始全长分别为(13.29±0.52)mm、(12.29±0.44)mm、(15.81±0.50)mm,实验周期分别为25 d、25 d、15 d。结果表明:与其他饵料组相比,投喂专用仔鱼料组,异齿裂腹鱼仔鱼和拉萨裂腹鱼仔鱼的平均全长、全长增加倍数以及存活率均高于其他各组,并有显著差异;尖裸鲤仔鱼的平均全长和全长增长倍数也高于其他各组,但存活率较投喂卤虫无节幼体低,并有显著差异。     

美国白蛾各虫态发育历期试验观察

在恒温25℃、相对湿度75%,光照周期L∶D=16∶8条件下,观察美国白蛾各生态发育历期,结果显示,饲喂杨树叶片处理的各虫态平均历期为:幼虫期24.6～25.3d;蛹期12.3～19.0d;羽化-交尾1.8～2.5d;交尾-产卵期1.8～3.3d;产卵-孵化期8.0～8.5d。饲喂杨树叶片较饲喂家蚕饲料和924-1利于缩短美国白蛾发育周期和增加产卵量。     

A new type of lordosis and vertebral body compression in Gilthead sea bream,Sparus aurata L.: aetiology,anatomy and consequences for survival

A new type of vertebral malformation is described, consisting of deformed cartilaginous neural and haemal processes and the compression and fusion of vertebral bodies. The malformation is designated as haemal vertebral compression and fusion (haemal VCF). We studied the aetiology of the malformations and described microanatomical histopathological alterations. The malformations were detected during routine quality control in one of six monitored Gilthead sea bream populations. Haemal VCF affected the posterior part of the vertebral column (haemal vertebrae). In 20% of the deformed specimens, haemal VCF was combined with lordosis. At 35 dph (days post‐hatching), early anatomical signs of the haemal VCF consisted of abnormal centrum mineralization, malformed cartilaginous neural and haemal processes and developing lordotic alterations. The histological examination of the deformed individuals revealed that haemal VCF is preceded by notochord abnormalities. The frequency of deformed individuals was three times higher at 35 than at 61 dph (50.3% vs. 17.2%, n = 157 and n = 250, respectively). No signs of repair or reversion of malformations have been observed. Thus, the steep decrease in deformities in older animals suggests that haemal VCF is linked to high mortality rates. The results are discussed in respect of the possible causative factors of haemal VCF.     

灯笼鱼属仔稚鱼的发育形态及其分类检索

研究灯笼鱼属仔稚鱼的发育形态与分类特征,为以后相关的海洋生态调查的仔稚鱼种类鉴定提供参考资料,以相关的灯笼鱼属仔稚鱼形态与分类特征文献为依据,对1978年4—5月和8—10月太平洋中部热带水域、1979年5—6月西太平洋热带水域,1984年4—7月、1984年12月—1985年1月和1985年4—6月东海外海黑潮流域调查采集到的灯笼鱼属鱼类的仔稚鱼样品进行分类鉴定,共鉴定了栉刺灯笼鱼、闪光灯笼鱼、粗鳞灯笼鱼、斑点灯笼鱼、金焰灯笼鱼、东方灯笼鱼、钝吻灯笼鱼和灯笼鱼Myctophum sp.等8种仔稚鱼。观察和描述了其个体发育形态,并引用发光灯笼鱼、双灯灯笼鱼、粗短灯笼鱼、短颌灯笼鱼、Myctophum sp1.和Myctophum sp2.的形态特征,构建了目前全球已了解的11种灯笼鱼以及3种未定到种的Myctophum sp.、Myctophum sp1.和Myctophum sp2.仔稚鱼的种类分类检索表。观察结果显示,灯笼鱼属仔稚鱼鱼体细长,头部呈三角形、微扁,眼非圆形,眼部脉络组织发达或有发达眼柄支撑,颊部、胸鳍和鳃盖骨边缘具黑色素,消化管末端内侧或外侧色素均匀分布,两颌生有小利牙,具脂鳍,发育过程除金焰灯笼鱼外均具有发达扇形胸鳍,这是灯笼鱼属仔稚鱼共有的形态特征。金焰灯笼鱼形态特征独特,头部非常扁平,两眼眼柄非常发达,向体外两侧伸展,消化管末端游离于体外。仔稚鱼两眼前后是否具眼柄和眼部脉络组织形状,上下颌骨末端是否具黑色素,胸鳍柄和鳍条间黑色素有无,尾柄末端、脂鳍和臀鳍后缘是否具黑色素斑分布,消化道末端色素的分布等发育形态特征是该属仔稚鱼种类鉴别和分类的主要依据。