NORMAL EMBRYONIC STAGES OF POLYODON SPATHULA ( WALBAUM )
NORMAL EMBRYONIC STAGES OF POLYODON SPATHULA ( WALBAUM )
复制标题
DOI：
10.1002/jmor.1051140307
复制
发表时间：
1964-01-01
影响因子：
1.5
通讯作者：
NEEDHAM, RG
中科院分区：
文献类型：
--
作者：
BALLARD, WW;NEEDHAM, RG
这种“活化石”的胚胎在1960年之前是没有见过的，这是对一个完整系列的第一次描述。从形态和时间上确定了从受精到取食的41个阶段。器官发生被描述为活胚胎。像其他硬骨鱼类一样，多齿鱼有完全的卵裂，原肠胚形成和神经调节与两栖类相似。它的肝脏与全骨鱼和硬骨鱼不同，它的肝脏长在内胚层细胞内的卵黄块的下表面。原肾是由原始肾管的长发夹状偏移形成的。多齿鱼胚胎学的大多数特征在中华鲟中是密切相似的，其发育阶段被定义为适合这两种软骨动物的发育。
Embryos of this "living fossil" were not seen before 1960 and this is the first description of a complete series. Forty-one stages are defined morphologically and timedfrom fertilization to feeding. Organogenesis is described as seen in the living embryos. Like few other bony fishes, Polyodon has a total cleavage, and gastrulation and neurolation are similar to those of Amphibia. Its liver, unlike those of holosteans and teleosteans, arises on the lower surface of a yolk mass contained within endodermal cells. The pronephros arises through convolution of a long hairpin-shaped excursion of the primitive kidney duct. Most of the peculiarities of Polyodon embryology are closely paralleled in sturgeons, and the stages are defined to fit the development of both kinds of chondrosteans.