可口革囊星虫(Phascolosoma esculenta)胚胎及幼虫发育研究  

STUDY ON THE EMBRYONIC AND LARVAL DEVELOPMENT OF PHASCOLOSOMA ESCULENTA

作　　者：金春华[1] 竺俊全[1] 许式见[1] 王伟[1] 

机构地区：[1]宁波大学教育部应用海洋生物技术重点实验室,宁波315211

出　　处：《海洋与湖沼》2011年第1期94-100,共7页Oceanologia Et Limnologia Sinica

基　　金：浙江省自然科学基金项目;Y304096号;浙江省科技计划项目;2004C33095号;教育部创新团队项目;IRTO734号

摘　　要：采用人工授精的方法获得受精卵,在人工培育条件下观察了可口革囊星虫胚胎及幼虫发育过程及其盐度和pH对胚胎发育的影响,探究可口革囊星虫胚胎及幼虫发育规律。结果表明,可口革囊星虫胚胎及幼虫发育过程为:受精卵→卵裂→囊胚→原肠胚→担抡幼虫→海球幼虫→稚虫。在水温28—29℃、盐度23、pH8.1—8.2条件下,受精后7h10min发育到担轮幼虫;受精后45h30min,胚胎发育结束,孵化出海球幼虫;胚胎发育的适宜盐度为17.10—30.15、适宜pH为7.40—8.56;海球幼虫经16—18d培育变态为稚虫。可口革囊星虫担轮幼虫以自身卵黄为营养,浮游生活,具趋光性;海球幼虫早中期浮游生活,具趋光性,后期逐渐转向底栖;稚虫底栖生活,以单细胞藻类及有机碎屑为食。可口革囊星虫幼虫发生模式上属间接发生类型。To elucidate the embryonic and larval development of Phascolosoma esculenta, fertilized eggs of P. esculenta by artificial insemination were obtained and observed.. The processes of embryonic and larval development were observed, and the impact of salinity and pH value on the embryonic and larval development was investigated. The results indicated that the embryonic and larval development of P. esculenta undergo the following stages, i.e., zygote, cleavage, blastula, gastrula, trochosphere, pelagosphere, and finally juvenile worm stages. It took 7 hrs 10min after fertilization for an egg developed into trochosphere when the salinity is at 23.0, pH at 8.1--8.2, and water temperature at 28--29℃. 45.5h is needed for finishing embryonic development after fertilization. The optimal salinity and pH for embryonic development was 17.10--30.15 and 7.40--8.56, respectively. It took 16--18 days for pelagosphera larva to develop into juvenile worm. The trochosphere, which had a long apical tuft of cilia with a pair of red eyespots at the anterior part of the back, fed on its own yolk sac, lived a planktonic life and exhibited phototaxis. The pelagosphera larva, consisting of a collar-like head and saccular trunk and with a pair of red eyespots located at the rear of head, had a pelagic living at early-middle stage and then altered to a benthonic living at later stage. Juvenile worm lived a benthonic life and mainly fed on single-cell planktonic mircoalgae. The cleavage pattern ofP. esculenta was spiral and holoblastic and the larval development pattern was indirect.

关 键 词：可口革囊星虫 胚胎与幼虫发育 盐度 PH 

分 类 号：Q253[生物学—细胞生物学]