During fetal development, the entire body derives from three layers, called germ layers, the ectoderm, mesoderm, and endoderm.

胚胎发育过程由三个胚层组成，分别是：外胚层、中胚层与内胚层。

The jellyfish body is mainly composed of mesoglea, a jelly-like fluid sandwich between the outer ectoderm and the inner digestive cavity the endoderm.

水母的身体主要由中间胶质组成，中间胶质是一种果冻状的液体，夹在外外膜和内消化腔内膜之间。

The layer of cells, the endoderm, is thin, like the ectoderm, allowing nutrients to be directly absorbed into the surrounding cells.

细胞的内胚层很薄，像外胚层一样，可以让营养物质直接被周围的细胞吸收。