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61.
L-DOPA对西施舌眼点幼虫附着变态诱导的研究 总被引：2，自引：0，他引：2
采用试验水体中添加化学诱导物的方法研究L-DOPA(L-多巴)对西施舌(Coelomctraantiquata)眼点幼虫附着变态的诱导作用。结果表明,L-DOPA能诱导西施舌眼点幼虫变态,但对其附着的诱导效果不明显。用直径小于1 mm的细沙为附着基质,1×10-6mol/L的L-DOPA处理西施舌眼点幼虫12 h,变态率为73.3%,对照组为62.6%。浓度为1×10-7mol/L的L-DOPA处理西施舌幼虫12 h,生长速率为25.6%,对照组为14.7%,表明适当浓度的L-DOPA能促进西施舌幼虫的生长。在无沙附着的条件下,西施舌幼虫可正常附着变态,但生长速率较低且变态后死亡率高。 相似文献
62.
饥饿对中国龙虾叶状幼体Ⅰ期发育、摄食及存活的影响 总被引：6，自引：1，他引：6
中国龙虾叶状幼体Ⅰ期在饥饿条件下的生长发育、变态、存活的研究结果表明:初孵叶状幼体耐饥饿能力较强,完全饥饿144h,成活率为100%,饥饿192～216h,成活率为76%～68%.由生长和变态来看,推迟24～36h投饵,对叶状幼体Ⅰ期的生长没有明显影响.在摄食饵料方面,初孵幼体饥饿144h,仍然有55%的幼体具有摄食能力.饥饿24～120h的初期叶状幼体摄食卤虫幼体的大小(体长为349.5～604.9μm)可达到自身体长的1/2～1/3.当叶状幼体连续摄饵时间达60h,体内储存一定的营养后,即使不再喂食,幼体也能变态,但变态率较低.由间隔投饵效果来看,每隔8,16,24h投饵,幼体的发育变态差异不大.这些研究结果对开展龙虾基础生物学与人工育苗技术研究,提高育苗成活率将有一定的参考意义. 相似文献
63.
为了得到壳型规则、大小均一的单体牡蛎,作者以葡萄牙牡蛎(Crassostrea angulata)和长牡蛎(Crassostrea gigas)眼点幼虫为材料,从肾上腺素(EPI)浓度梯度、处理时间梯度和眼点幼虫密度梯度3个因素诱导产生不固着变态的单体牡蛎。结果表明,葡萄牙牡蛎用EPI处理24 h的最适浓度为5×10–4 mol/L,不固着变态率为72.8%,在该最适浓度下,最佳处理时间为12 h,不固着变态率为82.7%。长牡蛎用EPI处理6 h的最适浓度为5×10–5 mol/L,不固着变态率为53.2%,在该最适浓度下,最佳处理时间为8h,不固着变态率为56.8%,眼点幼虫密度在80个/m L以下EPI处理效果没有显著性差异。对长牡蛎幼虫进行后续生长测定,结果显示EPI处理组幼虫的壳长、壳高和存活率要高于对照组,表明EPI可能促进牡蛎幼虫变态长出次生壳并提高其生存能力。 相似文献
64.
海洋附着细菌对冠瘤海鞘幼体附着和变态的影响 总被引：7，自引：0，他引：7
从冠瘤海鞘、皱瘤海鞘及乳突皮海鞘的被囊表面及其附着基和附近的海水中分离到290株细菌,根据其形态和生理生化特征,将其鉴定至弧菌属、肠杆菌属和无色杆菌属等10个属.分析海鞘被囊表面及其附着基和海水中的细菌组成,并从各属中挑出的29株细菌中分离筛选出附着能力较强的9株.将这9株细菌分别制成不同的单种细菌黏膜及9种细菌混合黏膜,检测细菌黏膜对冠瘤海鞘幼体附着和变态的影响.结果表明不同细菌黏膜对冠瘤海鞘幼体的附着和变态起不同的作用.无色杆菌属H-13显著地促进海鞘的附着和变态;弧菌属的H-4对海鞘的附着和变态均起抑制作用;弧菌属H-9明显地促进附着却强烈抑制海鞘幼体变态;其余细菌仅仅对海鞘幼体附着或变态的一个过程起作用或是对两者都没有明显效果. 相似文献
65.
Abstract. The influence of bacterial exopolymers and conspecific adult extract of Balanus amphitrite on metamorphosis of cyprid larvae at different salinities has been evaluated through laboratory assay. The bacterial exopolymers epm extracted from Pseudomonas, Acinetobacter and Enterobacteriaceae strains, isolated from the shell surface of Balanus amphitrite , were examined for their influence on metamorphosis, both individually and in combination with conspecific adult extract at 15, 25, 35 and 45% salinities. The epm extracted from the pool of these three strains mixed culture was also tested similarly.
The influence of epm varied with the strain of bacteria and salinity. The surface condition and time interval significantly influenced the metamorphosis rate. The interaction between these two variables, however, did not change in any combination, irrespective of the bacterial strain used. The Pseudomonas epm promoted metamorphosis at 15%, but was inhibitory at 45%. The Acinetobacter epm induced metamorphosis to a level of 71 ± 15% at 15%. No such metamorphosis promotion was observed with the epm of this strain at higher salinities and the influence was less than the conspecific adult extract. The epm of Enterobacteriaceae and mixed culture epm did not promote metamorphosis. There was no appreciable change in the metamorphic rate in the control conditions at 25%, 35% and 45% salinities and the rate was much lower than that obtained with conspecific adult extract. At 15%, however, the influence of adult extract was closer to that of the control condition. This shows that even in the absence of any attractant, the settlement intensity is positively influenced at mid-salinity of the barnacles' natural distributional range. 相似文献
The influence of epm varied with the strain of bacteria and salinity. The surface condition and time interval significantly influenced the metamorphosis rate. The interaction between these two variables, however, did not change in any combination, irrespective of the bacterial strain used. The Pseudomonas epm promoted metamorphosis at 15%, but was inhibitory at 45%. The Acinetobacter epm induced metamorphosis to a level of 71 ± 15% at 15%. No such metamorphosis promotion was observed with the epm of this strain at higher salinities and the influence was less than the conspecific adult extract. The epm of Enterobacteriaceae and mixed culture epm did not promote metamorphosis. There was no appreciable change in the metamorphic rate in the control conditions at 25%, 35% and 45% salinities and the rate was much lower than that obtained with conspecific adult extract. At 15%, however, the influence of adult extract was closer to that of the control condition. This shows that even in the absence of any attractant, the settlement intensity is positively influenced at mid-salinity of the barnacles' natural distributional range. 相似文献
66.
双峰无齿蚌Anodonta bigibba(Heude)非寄生变态发育的研究 总被引：3，自引：1，他引：2
1993年4、5月份观察到双峰无齿蚌Anodonta bigibba(Heude)母体排出的不是钩介幼虫,而是幼蚌。幼蚌壳中具一呈似三角形、较厚的钩介幼虫外壳,其腹缘顶端具壳钩。幼蚌在原钩介幼虫壳缘生长了1—4环新壳,而且具育带纤毛的足、前后闭壳肌、管状鳃原基和肛门孔等。幼蚌在室内试养存活了39天,显示已具独立生活能力。研究表明,该蚌钩介幼虫在母体育儿囊中已经历并完成变态,发育成幼蚌。这是我国首次发现的一种非寄生变态发育的珠蚌类,对于研究我国珠蚌类的进化及与世界淡水贝类的亲缘关系有着重要价值。此外,鉴于双峰无齿蚌与背角无齿蚌Anodonta woodiana(Lea)的成体壳形和发育生活史的不同,应恢复Heude建立的双峰无齿蚌的种名。 相似文献
67.
实验以凡纳滨对虾受精卵和各期幼体为试验材料,探讨了高盐和温度对受精卵孵化和幼体发育的影响,以及各期幼体对高盐的耐受性。结果表明,高盐胁迫和温度显著影响受精卵的孵化率、初孵时间和集中孵化时间(P0.05)。随盐度和温度升高,平均孵化率呈先升高后降低的变化趋势,盐度30和温度32°C时孵化率最高。盐度由33升至36时孵化率由74.67%下降到50.79%,盐度39时孵化率仅为3.42%,盐度42无幼体孵出。受精卵最早可在7.5h左右完成幼体破膜孵化。同一温度下,初孵时间随盐度的升高而延长。盐度27—33和温度30—33°C时,受精卵集中于胚胎发育后的7.5—11.5h完成孵化,时间最短;溞状幼体对高盐胁迫的耐受性随变态发育逐渐提高,表现为Z3Z2Z1;糠虾各期幼体及仔虾P1—P3间耐盐性均无显著差异(P0.05)。此外,幼体的发育指数也随盐度升高而下降,盐度越高,幼体发育越慢。结果说明,高盐和低温会抑制凡纳滨对虾受精卵孵化和幼体变态,受精卵孵化的盐度上限在39—42之间。 相似文献
68.
The effects of temperature and substrate on ontogenetic patterns and settlement behavior of bastard halibut, Paralichthys olivaceus （T. et S.） were studied in a series of laboratory experiments. Analysis on stage-based data revealed that except for settlement, and compared to the substrate, the ambient temperature dominantly controlled the hatch success and subsequent development of the species. The oosperm optimum survival rate of 60% during hatching occurred at 20℃, and survival rate of 29%, at 18℃ for larval rearing. The survival rate of larvae reared under variable temperature of 3.5-4.5℃ was higher than that of those reared under stable temperature. The maximum survival rate of 29%, corresponded to variation at temperature of 4℃. With increase in age newly settled juveniles preferred to lie on the fine substrate and gradually moved on the coarse substrate. GLM （general linear model） analysis showed that the combination of temperature and substrate had no significant impact on the survival of settling larvae, but definitely affected the duration of settlement. 相似文献
69.
70.
The larvae of Styela canopus show the highest rates of settlement and metamorphosiswhen treated with 40 mM KCl-elevated seawater at 25 ℃ in temperature and 27.0 in salinity. Inducedby 40 mM KCl-elevated seawater, it took Styela canopus larvae approximately 3 h after hatching to de-velop competence to settle and metamorphose. The present experiment shows that Styela canopus larvaeis an ideal model organism for examining the efficiency of antifouling substance. 相似文献