| 摘要: |
| 于水温（18.0±1.0）°C、盐度20、pH 8.1±0.2条件下，以日本囊对虾秋繁同生群仔虾[总长（7.643±0.639）mm]为实验对象，以离水干露为胁迫因子，在确认其离水干露160min内的复水成活率为100%和离水干露240min时的复水存活率略低于5%后，借助显微扫描像素测量技术和多元分析方法定量研究了A、B、C、D、E实验群体（依次为干露处理160-180、180-200、200-220、220-240min时段内的死亡群体和干露处理240min时的存活群体）间形态表型特征的差异。结果表明：（1）在所涉15项形态性状中，各实验群体间均无显著差异（P>0.05）的性状多达10项，依次为第一触角柄长、额剑长、眼径、第一腹节长、第二腹节长、第三腹节长、第四腹节长、第五腹节长、尾节长和尾节高；（2）在所涉17项形态比例指标中，各实验群体间均无显著差异（P>0.05）的指标仅为3项，依次为头胸甲长/总长、头胸甲高/头胸甲长和尾节高/尾节长，群体间的欧氏距离均达到极显著水平（P<0.01），且有随耐干露性能差异的增大而呈显著增大的趋势；（3）经主成分分析，提取到的4个特征值均大于1的主成分，累计贡献率达91.018%，其中第1主成分的贡献率高达57.974%，其载荷绝对值大于0.5的主要变量占形态比例指标总数的64.706%；（4）将A、B、C、D实验群体统归为干露处理淘汰群，E实验群体定义为干露处理选留群。采用逐步判别法，所建的Fisher分类函数方程组可较清晰地区分淘汰群和选留群个体，其中选留群个体的判别准确率P1、P2分别为100%和84.75%，淘汰群个体的判别准确率P1、P2分别为82%和100%，两者综合判别准确率为91%。 |
| 关键词: 日本囊对虾 仔虾 形态表型 干露胁迫 多元分析 |
| DOI：10.11693/hyhz20160200032 |
| 分类号: |
| 基金项目:宁波市科技富民计划项目“日本囊对虾生态高效养殖关键技术集成与示范（2016-2018）”；舟山市科技计划项目，2013C41013号；宁波市海洋渔业局科技项目“2015年宁波市本级增殖放流技术指导和效果评价”。 |
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| THE EFFECT OF MORPHOLOGICAL TRAITS ON THE SURVIVAL OF THE POST LARVA MARSPENAEUS JAPONICUS WHEN EXPOSED TO AIR |
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WANG Zhi-Zheng1, ZHU Ben-Qiang1, REN Su-Yi1, ZHU Hai-Jun1, SHEN Wei-Liang2
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1.Zhejiang Ocean University, Zhoushan 316022, China;2.Marine and Fishery Research Institute of Ningbo, Ningbo 315000, China
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| Abstract: |
| A study was conducted to investigate the effect of various morphological traits on the survival of the post larva Marspenaeus japonicas when exposed to air for an extended period. Research specimens were kept under the following conditions prior to the experiment: water temperature (18.0±1.0)°C, salinity 20, and pH 8.1±0.2. the post larva M. japonicas from the autumn propagation [total length (7.643±0.639)mm] were exposed to air and observed until they all had died. The survival rate was 100% until 160 min, and mortality was monitored until survival dropped below 5%, which was recorded at 240 min. Shrimp were separated into five groups according to their time of death after exposure to air. Groups were allocated as follows: A 160-180min, B 180-200min, C 200-220min, D 220-240min and E > 240min. Microscopic scanning measurement and multivariate analysis methods were used to study the differences of morphological traits between groups. The results showed that: (1) Among the 15 morphological indices , there were no significant differences in 10 indices between all tested groups; which were the antennule stalk length, rostrum length, eye diameter, promerous length, second abdominal segment length, third abdominal segment length, fourth abdominal segment length, fifth abdominal segment length, telson length, and telson height, respectively. (2) Among the 17 proportion indices, there were no significant differences in only 3 indexes between all tested groups, which were carapace length/total length, carapace height/carapace length, and telson height/telson length. The level of Euclidean distance was extremely significant differences (P<0.01). The results of a principle component analysis (PCA) showed that the accumulative contribution of the four principal components was 91.018% and the eigenvalues of these components were all larger than 1. The contribution of principal component 1 was 57.974% and the main variables whose absolute loading value was more than 0.5 accounted for 64.706% of the total proportion indexes. In discriminate analysis the groups A, B, C and D were concluded as elimination groups and group E was concluded as a retention group. The independent variables were used to establish Fisher classification function equations which could clearly distinguish the individual in elimination group and retention group. The result showed that the discriminate accuracy rate of individuals in retention group for P1 and P2 were 100% and 84.75% respectively. The discriminate accuracy rate of P1 & P2 for the elimination group was 82% and 100% respectively and the synthetic discriminate accuracy rate was 91%. |
| Key words: Marspenaeus japonicas post larva morphological traits desiccation multivariate analysis |
