摘要
采用常规石蜡切片和液体石蜡透明卵壳的方法 ,系统地观察了真水狼蛛的胚胎早期、体节期、胚胎逆转期和幼虫期 4个发育阶段的形态特征和发育过程 ,并测定了胚胎发育过程中卵内主要化学物质含量的变化。在 2 8℃时 ,真水狼蛛的卵从产卵到孵化共需 144小时 ,其中胚胎早期 42小时 ,体节期 33小时 ,胚胎逆转期 2 7小时 ,在胚胎逆转期后进入前幼虫期 ,前幼虫期 42小时。真水狼蛛的胚胎逆转现象很明显 ,表明真水狼蛛的进化程度较高。在胚胎发育过程中 ,卵的含水量、含脂量和卵重在胚胎发育 2 4hr后开始下降 ,卵的蛋白质含量在48小时后也开始下降 ,含糖量下降不明显。
We studied the morphological characteristics and the changes of biochemical substances in the embryos during embryonic development in Pirata piraticus . At 28℃, embryonic development took 144 hr, with 42 hr at early embryo stage, 33 hr at metameric phase, 27 hr at inversion phase and 42 hr at pre larva phase. The early embryo stage ranges from the beginning of the first cleavage to blastodisc stage. During this period, the nucleus division occurred in the center of the zygocyte firstly and then these divided nuclei migrated into the edge where they were surrounded by cytoplasm thus formed into the blasterderm. About 23 hours later, the blastula contracted. In the meantime, most blastocytes aggregated in the upper of the embryos and came to blastodisc. Afterwards, these cells differentiated into three kinds of shapes and located in different position. About 30 hours after oviposition, the cumulus was formed. During the metameric phase, the blastodisc prolonged and formed a lycotropal germinal band, which gradually differentiated into head lobe, caudal lobe and the middle five somites and made further development of the primodia of chelicera, taster and walking legs. About 72 hours after oviposition, in the middle of the germinal band, a median groove appeared and gradually widened, which suggested that the embryo developed into the inversion stage. In this stage, embryonic lateral plate moved towards the dorsal lateral surface and concrescent in the dorsal line. The walking legs differentiated seven segments. The filators were developed from the rudiments of appendages in the fourth and fifth somites. At the end of this stage, the embryos had the typical morphological characters of spiders. The heart and stomach were developed in larva phase and the larva can move slowly. Three pairs of filators came to be formed in 11～12 days following oviposition. The first instar larva molted one time thus enter the second instar stage. The spider in larva phase before the second instar stage couldn't catch foods, so they supported themselves by yolk. With the development of the spider, wet weight of egg, and water, fat contents of embryos started to decrease at about 24 hours post oviposition. The contents of protein began to decline at 48 hours after oviposition. However, the content of carbohydrate had little change.
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2001年第2期190-195,T001,共7页
ACTA ZOOLOGICA SINICA
