Larval development of the fiddler shrimp,Metapenaeopsis stridulans (Alcock, 1905) (Decapoda: Penaeidae) reared in the laboratory

Larvae of Metapenaeopsis stridulans (Alcock, 1905) from Malaysia were successfully reared in the laboratory from the egg to the 1st post-larval stage. The larvae developed through six naupliar, three protozoeal and four mysis stages. The morphology of all these larval stages is described and figured.     

Estimation of the stock size of adult Nephrops norvegicus (L.) from larvae surveys in the western Irish Sea in 1982

This paper describes the results of Nephrops larvae surveys in the western Irish Sea from April to June 1982. Total production of Stage I zoea obtained from the seasonal production curve is used, together with an estimate of effective fecundity, to assess the number of mature females contributing to the season's hatch. Total production of Stage I zoea was also obtained from the intercept at zero time of the stage to stage mortality regression. Length and weight data from the fishery allow an estimate of the biomass of the mature female stock to be made.     

几种甲萘醌化合物对摇蚊幼虫的杀生研究

采用易被环境分解的维生素K3、其基本成分β-甲基萘醌(MQ)和同系物三氨基三嗪甲萘醌亚硫酸盐(MTB),对在给水系统中出现的4龄摇蚊幼虫进行了杀生实验.实验结果和分析表明:MQ和MTB杀灭效果显著,半致死质量浓度低于1.8 mg.L-1,杀灭过程遵循Chick定律.求出了杀灭率和质量浓度与接触时间乘积之间的关系.在实际应用中,采用MQ比较经济,其安全质量浓度低于7 mg.L-1,在80%杀灭率时的质量浓度与接触时间乘积约为17 mg.L-1.h.     

盐度对西施舌Coelomactra antiquata（Spengler）幼虫和贝苗生长发育的影响

本文运用生物统计法确定西施舌幼虫和贝苗的适宜盐度范围，结果表明。Ｄ形幼虫、壳顶幼虫和贝苗对盐度的耐受力不同。Ｄ形幼虫生长的适盐范围为１７．２７～２７．９０‰，且生长和存活的最适盐度是１７．２７～１９．９３‰；壳顶幼虫生长的适盐范围向低盐度延伸，为１３．２９～２７．９０‰，生长和存活的最适盐度为１９．９３‰。平均壳长２．９ｍｍ的贝苗存活适盐范围向高盐度延伸，为１３．２９～３５．８７‰，其中２７．９０‰是贝苗生长和存活的最适盐度。     

Role of low ecdysteroid levels in the early last larval instar ofBombyx mori

The relationship between juvenile hormone and ecdysteroid titers during the early stage of the last larval instar of the silkworm,Bombyx mori, was examined in this study. When larvae were fed 20-hydroxyecdysone-supplemented mulberry leaves throughout the last larval instar, 100% underwent supernumerary larval molting instead of metamorphosis. The application of juvenile hormone mimic during the early last instar did not induce supernumerary larval molting, but did delay metamorphosis. Temporal and quantitative ecdysteroid titer measurements revealed that in normal larvae the titers maintained very low levels (3–12 ng/ml) during the early stage of the last instar; however, in 20-hydroxyecdysone-treated larvae, levels ranging from 24 to 45 ng/ml were detected, and a major peak (246 ng/ml) was observed on day 6. These results show that very low ecdysteroid titer levels during the early stage of the last larval instar may play an important role in initiating decreases in juvenile hormone titers as well as in directing metamorphosis.     

缢蛏幼体的趋性行为

研究了缢蛏 sinonovacula constricta(Lamarck)幼体的趋光性和趋地性。该种幼体在早期表现为负趋地性,随后却转为正趋地性,幼体整个浮游期均维持正趋光性。D形面盘幼体的趋光性强于趋地性,而壳顶面盘幼体和足面盘幼体的趋光性弱于趋地性。幼体对于不同光强的反应差异较小,但不具光探性反应。初步认为,缢蛏幼体缺乏随光强而进行垂直移动。     

中国蜉蝣目稚虫科检索表(昆虫纲)

提供了蜉蝣目中国所有已知15科稚虫的检索表，并对重要检索特征进行了详细图示．     

亲鱼营养状况对花尾胡椒鲷仔鱼存活率的影响

以n 3高度不饱和脂肪酸 (n 3HUFA)含量为 0 1 6%、 1 2 7%、 2 36%和 3 47%的4种人工配合饲料及冰鲜杂鱼饲养花尾胡椒鲷亲鱼一周年 ,获得仔鱼后 ,在不投饵的情况下 ,比较各组初孵仔鱼在盐度 8、 1 6、 2 4和 32的水体中的存活率和饥饿耐力 .结果发现 ,0 1 6%组仔鱼的死亡高峰要比其它各组提前 2～ 3天 ,各组仔鱼在 8和 1 6盐度下的存活时间要比在 2 4和 32盐度下延长 1～ 2天 .这说明 ,亲鱼饲料中的n 3HUFA含量较低会降低仔鱼的耐饥饿能力和存活率 ,低盐度 ( 8～ 1 6)可能更适合培育花尾胡椒鲷仔鱼     

实验室条件下西藏冬虫夏草幼虫生理机制变化研究

为研究实验室条件下西藏冬虫夏草幼虫对温度、湿度、病害等条件的生理反应以及西藏冬虫夏草幼虫的食性情况,文章对西藏冬虫夏草幼虫的外部形态及其对温度和湿度的反应及食性等方面进行观察,并绘制出西藏冬虫夏草幼虫生长曲线。结果表明：①实验室中培养西藏冬虫夏草幼虫的最佳温度范围为12℃-14℃;②西藏冬虫夏草幼虫最喜啃食红萝卜,其次为土豆和莴笋;③西藏冬虫夏草幼虫对温度具有很高的敏感性,当温度达到20℃时,幼虫完全失去活动的能力,并且此时幼虫身体表面容易感染病菌。