Multivariate analysis for ordination and comparison of size of Artemia cysts

ThisresearchwasfundedbyNaturalScienceFoundationofFujianProvince.INTRODUCTloNBrineshrimpsaredistrbutedwidelyintheworld.Morethan35ohabitatshavebeenidenti-fiedsofar(VanhaeckeandSorgeloos,198O).Longadaptationtothenarrowbiotopscharacter-izedbyhighsalinityofsaltlakes,lagoonsandsaltfarms,thestrainhasdevelopedinherentcharac-terssuchascystsize,growthrateandtoleranttothehightemperature,etc.Thereforethecystbiometricshasoftenbeenusedinthespeciesidentification,asitisalsoeasyfordatagatheringwhencarr…     

Significance of cyst fragments of Artemia sp. recovered from a 27,000 year old core taken under the Great Salt Lake, Utah, USA

We present electron microscopic observations on fragments of encysted embryos of the crustacean,Artemia sp., recovered from a 27,000 year-old core section taken under the Great Salt Lake (GSL), Utah. The significance of these results comes from a consideration of the geological history of the GSL and the extraordinary properties and abundance ofArtemia cysts at this site. We make the case that this unique system, and probably other salt lakes as well, provides novel opportunities for the study of “ancient DNA” and related matters. The analysis provides the major focus of this paper, which we hope will stimulate interest in this aspect of salt lake research.     

Effect of artificial regulations ofArtemia n−3 HUFA content on growth and survival of black seabream (Sparus macrocephalus) larvae

The requirement for dietary n−3 HUFA (highly unsaturated fatty acid) for growth and survival of black seabream (Sparus macrocephalus) larvae was tested usingArtemia with various levels of n−3 HUFA. Four treatments withArtemia differing in their n−3 HUFA were prepared by feeding them various oil emulsions. The results indicated that dietary n−3 HUFA significantly influences fish n−3 HUFA levels and are necessary for good growth and survival of black seabream larvae. The proper value of n−3 HUFA level and DHA, EPA level inArtemia should be 4.273% and 0.873% (wet weight) for good growth and survival in black seabream larvae respectively. Contribution No. 3044 from the Institute of Oceanology, Chinese Academy of Sciences. Project 39470562 supported by NSFC.     

卤虫繁殖机制的研究——Ⅰ.卵子发育过程中染色体的变化

本文以卤虫的生殖细胞卵子作为材料进行染色体标本制备,具体研究了卤虫卵子在发育过程中染色体的变化,探讨致使孤雌生殖卤虫染色体自然加倍的可能途径,以及两性生殖卤虫卵子发生受精的具体地点。     

卤虫杂交品系生化特性的初步研究

选择两性生殖品系（我国山西运城两性生殖品系）的雌体卤虫与孤雌生殖品系（天津塘沽品系）的雄体卤虫，于实验室内获得杂交品系，并对此杂交品系和其亲本品系进行生化特性的比较分析。①同工酶分析的结果表明：杂交F1代雌、雄个体和双亲品系雌、雄个体间的过氧化物酶表现基本相同；F1代的葡萄糖－6－磷酸脱氢酶表现出双亲间的过渡状态；F1代的肌浆蛋白酶带的数量、活性都高于亲本。②进一步对杂交F1代、山西运城两性生殖品系的氨基酸种类和含量做了比较分析，结果表明：杂交品系的氨基酸总含量明显高于其亲本，且含有单一亲本所不具有的氨基酸（如胱氨酸）组成。本实验结果显示，通过杂交手段可显著提高卤虫遗传变异水平，并且是选择高卤虫营养品系的手段之一。     

氨氮对我国不同产地卤虫的急性毒性试验

采用静水生物试验法测定了ＮＨ３－Ｎ对我国新疆艾比湖（ＡＢ），青海柯柯湖（ＫＫ），海南莺歌海（ＹＧＨ），山东埕口（ＣＫ）产地卤虫的初孵无节幼虫，拟成虫及成体的急性毒性试验。结果表明：１．不同发育阶段的卤虫对氨氮的耐受力是：成虫＞初孵无节幼虫＞拟成虫＞。２．不同产地卤虫对氨氮的耐受力有一定的差异，ＡＢ、ＫＫ、ＣＫ产地的卤虫对氨氮的耐受力均高于ＹＧＨ产卤虫。     

四产地卤虫休眠胚胎的发育期及细胞数的初步观察

用石蜡切片法观察了青海尕海(GH)、新疆阿其克库勒湖(AQK)、西藏(XZ,具体产地不明)、新疆鲸鱼湖(JYH)4个卤虫种群休眠胚胎所处的发育期,发现4个种群卤虫休胚胎均处于原肠期;通过压片染色法对4个卤虫种群休眠胚胎的细胞核计数显示,其胚胎细胞数分别为3441±164(GH),3412±171(AQK),3736±212(XZ),3861±155(JYH)个。     

卤虫（Artemia）“海孤一号”的基础生物学研究：1.存活与生长

本文对不同温盐条件下虫“海孤一号“的存活和生长情况进行了研究,结果表明：温、盐显著影响“海孤一号“的存活与生长,但温盐对存活的交互影响不显著。“海孤一号“的最适存活条件是温度２０－２５℃,盐度６０‰－１００‰,在不同温盐条件下,“海孤一号“的生长都经历了一个由慢到快再转慢的过程,Ｌｏｇｉｓｔｉｃ曲线能很好地拟合生长曲线,并把生长过程分为第一慢速生长期、快速生长期和第二慢速生长期。     

卤虫（Artemia）“海孤一号”的基础生物学研究：2.生殖与生命周期

本文对不同盐度条件下卤虫“海孤一号”的生殖及生命周期进行了观察和研究。结果表明：在较宽的盐度范围（３２％－１２０％）内卤虫都有很强的生殖能力,平均产后代７－１２次,每代１８０－２３０个,相邻两代间隔５．５－５．９天,同时存在生殖高峰期。在生殖参数中,产后代间隔时间最稳定,受盐度影响不显著。卤虫：海孤一号”在最适条件下,平均存活９０天,平均产后代约２０００个。     

“海孤1号”卤虫与杂交实验

报导我国一株罕见雄体出现率特别高的孤雌生殖卤虫“海孤1号”(OP1)。其罕见雄体出现率高于以往报导的10～20倍。利用这株卤虫的罕见雄体与两性生殖卤虫(A.sinica)的雌体进行杂交实验获得成功。