两种相手蟹线粒体 COI 基因序列的比较研究

测定了褶痕相手蟹(Sesarma plicata)和红螯相手蟹(S.haematocheir)线粒体细胞色素氧化酶I亚基(COI)基因片段的序列,其长度均为658bp,A,T,G,C的平均含量分别为28.6%,37.5%,17.0%,16.9%和29.5%,39.0%,16.2%,15.3%。2种蟹共出现5种单倍型,褶痕相手蟹2种,红螯相手蟹3种。两种间有75个(11.4%)多态性核苷酸位点,其中转换42个,颠换33个;种间差异远大于种内个体间差异。2种相手蟹的AT含量明显高于GC含量,这与其它海产甲壳动物COI基因研究结果相似。     

黄海南部和东海小黄鱼资源分布差异性研究

根据2006年6月～2007年4月黄海南部和东海底拖网监测调查资料,比较分析了2个海域小黄鱼资源密度指数(CPUE)分布、环境因子特征、CPUE与环境因子相关关系的差异.研究结果表明,黄海南部和东海小黄鱼资源密度指数分布除了秋季分布有显著差异之外(t′_((33))=2.69,P=0.011),其余季节分布均无显著差异(春季:t′_((43))=1.68,P=0.104;夏季:t′_((60))=0.31,P=0.756 7;冬季:t′_((43))=1.74,P=0.089);夏季的底层盐度分布和水深分布没有明显差异,在其他季节,黄海南部和东海的底层水温、底层盐度和水深分布等环境特征的差异明显,均达到极显著(P<0.01)或显著(P<0.05)水平;资源密度与环境因子回归分析和AIC模型选择中,2个海域夏季的小黄鱼资源密度受到有显著性影响的环境因子数最多,而冬季受到有显著性影响的环境因子最少.综合推断,黄海南部和东海小黄鱼具有不同空间分布特征和环境分布特征,2个海域的小黄鱼分属于不同种群,但在2个海域交界处有混栖种群.     

东山湾及其邻近海域鱼类群落结构分析

根据2009—2010年在东山湾及其邻近海域进行的4个航次底拖网的调查资料,分析了该海域的鱼类群落结构。调查共获得鱼类114种,其中暖水性鱼类有76种,暖温性鱼类有38种,优势种鱼类(IRI>1 000)共有8种,无常年优势种。多样性指数、季节更替指数和迁移指数分析显示,东山湾及其邻近海域各季节的Margalef种类丰富度指数(D)较低且季节变化明显,变化范围在3.70～5.34之间;Shannon-Weiner种类多样性指数(H′)较低;Pielou均匀度指数(J′)季节变化不明显;Jaccard相似性指数(Js)较低,季节间种类相似度较低。东山湾及其邻近海域鱼类群落结构稳定性相对较差。同时发现部分鱼类在湾内和湾外的分布与季节有关。     

氟硼酸根离子选择性电极测定沉积物中的硼

本文建立了氟硼酸根离子选择性电极测定沉积物中的硼。在建立本方法过程中,做了各种干扰条件实验,得到了满意的分析结果。实验中不用溴甲酚绿,效果很好,可延长电极寿命。实验证明,本法较比色法简单、快速、干扰少,而且不需大型仪器设备,可测定0.000x—0.x%的硼。     

Effects of temperature, pH and NaC1 on protease activity in digestive tract of young turbot, Scophthalmus maximus

The protease activity in digestive tract of young turbot Scophthalmus maximum was studied, and the optimal pH, temperature and NaCl concentration were determined for different portions of the fish＇s internal organs. The optimal activity in the fish＇s stomach was at pH of 2.2, while that in the intestinal extracts was within the alkaline range from 9.5 to 10.0. In hepatopancreas, the optimal pH was in low alkalinity at 8.5. The optimal reaction temperature was above 40℃ in stomach, intestine and hepatopancreas. With increasing temperature, the pH value increased in stomach, while in the intestine, an opposite tendency was observed due to combined effect of pH and temperature. NaCl concentration showed inhibitory impact on protein digestion in hepatopancreas. The main protease for protein digestion in turbot seemed to be pepsin. Moreover, the maximum protease activity in different segments of intestine existed in the hindgut.     

Vertebral deformities in hatchery-reared and wild-caught juvenile Japanese flounder,Paralichthys olivaceus

The present study compared vertebral deformities of hatchery-reared and wild-caught juvenile Japanese flounder,Paralichthys olivaceus.A total of 362 hatchery-reared flounder(total length 122.5-155.8 mm) were collected from three commercial hatcheries located in Yantai,East China,and 89 wild fish(total length 124.7-161.3 mm) were caught off Yangma Island near Yantai City(37°27′N,121°36′E).All the fish were dissected,photographed,and images of the axial skeleton were examined for vertebral deformities.Compared with wild-caught flounder in which no deformed vertebrae were detected,48(13.3%) hatcheryreared fish had deformed vertebrae.The deformities were classified as compression,compression-ankylosis,and dislocation-ankylosis.The vertebral deformities were mainly localized between post-cranial vertebra 1and 3,with vertebrae number 1 as the most commonly deformed.The causative factors leading to vertebral deformities in reared Japanese flounder may be related to unfavorable temperature conditions,inflammation,damage,or rupture to the intervertebral ligaments under rearing conditions.Furthermore,no significant difference in the total number of vertebral bodies was observed between wild-caught(38.8±0.4) and hatchery-reared flounder(38.l±0.9)(P0.05).However,the number of vertebral bodies of hatchery-reared and wild-caught flounder ranged from 35 to 39 and from 38 to 39,respectively.     

基于线粒体DNA部分片段探讨石鲽与星突江鲽的亲缘关系

比较分析了石鲽和星突江鲽线粒体基因组COI、Cytb基因以及D-loop片段总长度为1175 bp的核苷酸序列,探讨了石鲽与星突江鲽的亲缘关系。2种间共检测到95处核苷酸替代,蛋白质编码基因上的核苷酸替代主要是第三密码子位点上的同义替换。核苷酸组成分析结果表明:3个目的片段的鸟嘌呤(G)含量普遍较低,在2个蛋白质编码基因第三密码子位点上表现得尤为明显。线粒体COI、Cytb基因和D-loop片段序列分析显示石鲽与星突江鲽间平均遗传距离分别为0.043、0.062和0.153,属于属内种间差异水平。2种鲽鱼在线粒体基因组不同片段上存在明显的遗传分化,核苷酸替代速率由大到小依次为D-loopCytbCOI。贝叶斯法、邻近距离法和最大简约法构建的系统发育树一致,皆显示石鲽与星突江鲽遗传关系很近。基于Cytb基因片段序列的分析结果表明:石鲽与星突江鲽的分歧时间约为185万年,分化事件发生于更新世中期(Middle Pleistocene)。     

大菱鲆仔稚鱼期消化酶及碱性磷酸酶活性的变化

针对海水鱼类仔稚鱼期高死亡率的现状,本实验采集不同发育阶段的大菱鲆,分析测定了酸、碱性蛋白酶、淀粉酶和脂肪酶以及消化道碱性磷酸酶的活性变化,以期为提高大菱鲆仔稚鱼期的成活率和生长率以及优化饵料配方提供理论依据。结果表明,大菱鲆初孵仔鱼体内就已具有碱性蛋白酶活性,而酸性蛋白酶活性在15日龄左右胃腺出现时才测得。蛋白酶活性的3个极低值分别出现于仔鱼开口期,卵黄囊完全消失期和仔鱼向稚鱼的转变期。早期仔鱼体内表现出较强的淀粉酶活性。5日龄时其活性急剧下降,并一直保持较低的比活力水平。脂肪酶活性在仔稚鱼期一直很弱,进入幼鱼期后比活力迅速升高。碱性磷酸酶活性从初孵到50日龄左右始终保持较小幅度的上升,直到60日龄变态完成时才出现大幅度的升高。大菱鲆仔稚鱼发育过程中,消化道中各种酶活性变化显著,仔稚鱼变态完成后,蛋白酶、脂肪酶和碱性磷酸酶活性显著增强,这标志着大菱鲆由稚鱼期向幼鱼期的转变及消化机能的完善。