chordates

Styela plicata is an ascidian which belongs to class Ascidiacea, subphylum urochordata, phylum Chordates. About 2000 kinds of ascidians have been found in the nature and they distribute over the maritime space.

海鞘（Ascidian）属于脊索动物门（Chordates），尾索动物亚门（Urochordata），海鞘纲（Ascidiacea），全世界约有2000种，广泛分布于各海域中。

There are about 45.000 species of chordates, occupying marine, fresh and brackish water and terrestrial habitats.

有大约45.000种脊索动物,它们占据着海 、 淡水或淡咸水和陆地的生态环境.

Chordates are bilaterally symmetrical, triploblastic segmented coelomates which demonstrate a deuterostomic pattern of early embryonic development.

脊索动物两侧对称 、 胚层,分节的体腔,在胚胎发育的早期过程中,显示为后口类型.