温度和盐度对短节硬毛藻(Chaetomorpha brachygona Harvey)生长发育的影响研究

利用双因素实验和单藻培养等方法,对采自广东南澳岛的短节硬毛藻(Chaetomorpha brachygona Harvey)进行研究,在不同温度和盐度条件下,对该硬毛藻的生长、活力以及形态进行了观察与测定。结果表明,温度和盐度对短节硬毛藻的生长均有一定影响,当温度为20°C时,藻体培养第3、6和12天活力分别为0.70—0.75Y、0.60—0.70Y和0.55—0.65Y,培养12天时藻体有生殖细胞形成,此温度有利于藻体维持活力;温度为25—30°C时,培养第3天时会大量形成生殖细胞;在盐度10、20、40和50时,藻体的生长与温度相关,即30°C25°C20°C;在盐度20—30时,藻体长度最大达4.55 cm;在盐度10—30时,更有利于藻体生长,整体趋势为2030104050。因此,实验条件下,温度25—30°C、盐度10—30更利于短节硬毛藻的生长和形成生殖细胞。本实验表明,短节硬毛藻为暖水、广盐性种,有可能在我国南方海区大量生长并扩散,具有引发绿潮的潜力。     

大黄鱼(Larimichthys crocea)I型干扰素基因的特征与表达分析

采用RT-PCR和RACE-PCR技术克隆了大黄鱼(Larimichthys crocea)Ⅰ型干扰素基因全长cDNA序列及其基因组序列,并利用荧光定量PCR技术研究了该基因在大黄鱼不同组织中的表达谱,以及副溶血弧菌(Vibrio parahaemolyticus)、LPS、polyI:C刺激后大黄鱼脾脏、肝脏和头肾组织中该基因在转录水平的表达变化。结果表明,大黄鱼Ⅰ型IFN基因全长cDNA为878bp,开放阅读框558bp,编码185个氨基酸。推测的大黄鱼Ⅰ型IFN氨基酸序列N端含有20个氨基酸的信号肽,其后包含一个保守的IFabd结构域。大黄鱼Ⅰ型IFN基因包含5个外显子,4个内含子,在大多数组织和细胞中都有表达,其中在血细胞中表达量最高,肌肉中表达量最低。PolyI:C刺激可诱导大黄鱼Ⅰ型干扰素基因在脾脏、头肾和肝脏中的表达量显著上调;LPS刺激可诱导大黄鱼Ⅰ型干扰素基因在脾脏和肝脏中的表达量显著上调;灭活的副溶血弧菌可诱导大黄鱼Ⅰ型干扰素基因在头肾和肝脏中的表达量显著上调。     

大黄鱼溶藻弧菌病组织中巨噬细胞移动抑制因子的检测及意义

本文应用免疫组织化学方法,对健康大黄鱼和患溶藻弧菌病大黄鱼组织中巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF)蛋白进行了检测,以研究溶藻弧菌病大黄鱼组织中MIF的表达情况及其对预后的影响。结果表明,MIF在健康大黄鱼头肾、脾、肠各组织中均无表达;MIF在溶藻弧菌病大黄鱼各组织中高表达,表达强度从弱到强依次是肠、脾、头肾,MIF表达阳性率分别为:56%、64%、92%。推测MIF在大黄鱼溶藻弧菌病发病中发挥重要作用。     

Effect of Dietary Olaquindox on the Growth of Large Yellow Croaker（Pseudosciaena crocea R.） and the Distribution of Its Residues in Fish Tissues

Olaquindox（OLA）, one of quinoxaline-N, N-dioxides, has been put under ban. However it was used as a medicinal feed additive early; it promotes the growth of livestock and prevents them from dysentery and bacterial enteritis. In this study, we evaluated the effect of dietary OLA on the growth of large yellow croaker（Pseudosciaena crocea R.） and the histological distribution of OLA and its metabolite 3-methyl-quinoxaline-2-carboxylic acid（MQCA） in fish tissues. Four diets containing 0（control）, 42.5, 89.5 and 277.2 mg kg^-1 OLA, respectively, were formulated and tested, 3 cages（1.0 m × 1.0 m × 1.5 m） each diet and 100 juveniles（9.75 ± 0.35 g） each cage. The fish were fed to satiation twice a day at 05：00 am and 17：00 pm for 8 weeks. The survival rate of fish fed the diet containing 42.5 and 89.5 mg kg^-1 OLA was significantly higher than that of fish fed the diet containing 0 and 277.2 mg kg^-1 OLA（P 0.05）, while the weight gain rate of fish fed the diet containing 42.5 and 89.5 mg kg^-1 OLA was significantly higher than that of fish fed the diet without OLA（control）（P0.05）, but similar to that of fish fed the diet with 277.2 mg kg^-1 OLA. Fish fed the diet with 277.2 mg kg^-1 OLA had the highest content of OLA and MQCA in liver（3.44 and 0.39 mg kg^-1, respectively）, skin（0.46 and 0.09 mg kg^-1, respectively） and muscle（0.24 and 0.06 mg kg^-1, respectively）. In average, fish fed the diet containing OLA had the highest content of OLA and MQCA in liver which was followed by skin and muscle（P〈 0.05）, whereas OLA and MQCA were not detectable in control. Our findings demonstrated that OLA and MQCA accumulated in large yellow croaker when it was fed with the diet containing OLA, thus imposing a potential safety risk to human health.     

Effect of dietary olaquindox on the growth of large yellow croaker (Pseudosciaena crocea R.) and the distribution of its residues in fish tissues

Olaquindox(OLA), one of quinoxaline-N, N-dioxides, has been put under ban. However it was used as a medicinal feed additive early; it promotes the growth of livestock and prevents them from dysentery and bacterial enteritis. In this study, we evaluated the effect of dietary OLA on the growth of large yellow croaker(Pseudosciaena crocea R.) and the histological distribution of OLA and its metabolite 3-methyl-quinoxaline-2-carboxylic acid(MQCA) in fish tissues. Four diets containing 0(control), 42.5, 89.5 and 277.2 mg kg-1 OLA, respectively, were formulated and tested, 3 cages(1.0 m × 1.0 m × 1.5 m) each diet and 100 juveniles(9.75 ± 0.35 g) each cage. The fish were fed to satiation twice a day at 05:00 am and 17:00 pm for 8 weeks. The survival rate of fish fed the diet containing 42.5 and 89.5 mg kg-1 OLA was significantly higher than that of fish fed the diet containing 0 and 277.2 mg kg-1 OLA(P 0.05), while the weight gain rate of fish fed the diet containing 42.5 and 89.5 mg kg-1 OLA was significantly higher than that of fish fed the diet without OLA(control)(P0.05), but similar to that of fish fed the diet with 277.2 mg kg-1 OLA. Fish fed the diet with 277.2 mg kg-1 OLA had the highest content of OLA and MQCA in liver(3.44 and 0.39 mg kg-1, respectively), skin(0.46 and 0.09 mg kg-1, respectively) and muscle(0.24 and 0.06 mg kg-1, respectively). In average, fish fed the diet containing OLA had the highest content of OLA and MQCA in liver which was followed by skin and muscle(P 0.05), whereas OLA and MQCA were not detectable in control. Our findings demonstrated that OLA and MQCA accumulated in large yellow croaker when it was fed with the diet containing OLA, thus imposing a potential safety risk to human health.     

"银祥"牌大黄鱼慢沉饲料养殖大黄鱼试验

本文报告了用"银祥"牌大黄鱼慢沉饲料和鲜活饲料进行为期50d的大黄鱼(Pseudosciaenacrocea)养殖对比试验.结果表明，慢沉型颗粒饲料较适合大黄鱼的摄食习性和营养需求，有较低的饵料系数(1.62)，较高的存活率，降低了饲养成本，减轻了对水质的污染，明显地提高了大黄鱼网箱养殖的经济与生态效益.     

Comparative studies on some genetic characteristics among four large yellow croaker (Pseudosciaena crocea) populations

The genetic structure was compared among four large yellow croaker (Pseudosciaena crocea) populations, an important aquaculture species in China. RAPD and ISSR results show that the genetic distances between domestic stocks and their wild counterparts are significantly larger than those between the three wild stocks. The sequence of mtDNA cyt b shows that the three wild populations share the same sequence, with differences in the four bases from the cultured stock: two transitions [57(C-T), 291(G-A)] and two transversions [66(C-G),223(A-C)]. Cluster analysis reveals that the domestic stock has diverged from its parental wild stock [Min—Yuedong (Fujian Province—eastern Guangdong Province, China) stock]. Results demonstrate that 20 a of domestication of the Pseudosciaena crocea stock has resulted in significant genetic changes.     

大黄鱼溶藻弧菌LPS的间接ELISA检测

用酚 水法从20dm3溶藻弧菌培养液中分离得到脂多糖(LPS)97.6mg,以0.5mg cm3的LPS溶液通过耳缘静脉注射免疫实验兔,经过3次加强注射后从颈动脉放血制备抗血清.该抗血清的效价为1∶2560,对副溶血弧菌等10株细菌的交叉反应效价都较低.用免疫吸附过滤法去除血清中的非特异性成分.用吸附后的抗血清进行溶藻弧菌间接ELISA检测,其检测限为97×104个 cm3.以ELISA进行大黄鱼体内溶藻弧菌检测.结果表明:用LPS抗血清可以较为灵敏地检测大黄鱼体内的溶藻弧菌,该方法不仅可以用于诊断大黄鱼的溶藻弧菌病,也可以检测无病症带菌大黄鱼.     

番红砗磲幼虫的生长

番红砗磲Tridacna crocea Lamarck由D形幼虫发育至幼苗(第26天),壳长净生长106.62μm,壳高净生长104.41μm。其生长过程可分为三个时期:面盘期幼虫生长快,壳高的增长大于壳长的增长;变态期幼虫生长平缓,壳长与壳高的增长接近均衡;两者之间的足面盘过渡期幼虫生长出现两个停滞期。壳长与壳高的关系可以H=0.99998L-21.81275表示,它们分别与铰合部长度的变化有联系。壳长/壳高和(1/2)壳高/铰合部长度两个比率呈现一定的规律性,并可预测幼虫足的发生。     

大黄鱼早期发育过程中免疫器官的发生

应用显微与超微技术研究了大黄鱼(Pseudosciaena crocea)初孵仔鱼至60日龄幼鱼免疫器官——头肾、胸腺与脾脏的发育.结果表明,免疫器官原基出现的先后顺序是头肾、脾脏和胸腺.3日龄仔鱼出现头肾原基,原始造血干细胞最早被发现于头肾,很快分化成不同类型的细胞.4日龄仔鱼出现脾脏原基和胸腺原基.脾脏靠近内脏,含大量窦状隙,有丰富的毛细血管、血细胞与血小板.胸腺是最迟出现的淋巴器官,但发育较快.胸腺位于鳃腔背上角,主要由胸腺细胞(淋巴细胞)和上皮细胞组成,分为外区和内区,二者虽没有明显界限,但容易区分.免疫器官出现小淋巴细胞顺序是胸腺、头肾和脾脏;淋巴组织的发育相对滞后.在大黄鱼仔鱼早期发育阶段,非特异性免疫系统起着重要作用.