The two most basic types of embryo development in animals are the stereoblastula and the coeloblastula. These two types of embryonic development are the two earliest stages that occur in the development of animals. In order to understand the difference between them, it is important to consider the characteristics of each stage.
Stereoblastula is the first stage of embryonic development in animals. In this stage, the embryo is comprised of a single layer of cells that are surrounded by a protective membrane. This membrane is known as the blastocoele.
During this stage, the cells rapidly divide and migrate to form a hollow ball of cells. This structure is known as the blastula. The cells of the blastula can differentiate into different cell types that will be used in later stages of development.
Coeloblastula is the next stage of embryonic development. In this stage, the blastula begins to fold in on itself and form a double-layered structure. This structure is known as the gastrula. The two layers of the gastrula are the ectoderm and the endoderm.
During this stage, the cells of the ectoderm and the endoderm differentiate and form specific cell types that will be used in later stages of development.
The primary difference between a stereoblastula and a coeloblastula is the number of layers of cells. In the stereoblastula, there is only a single layer of cells while in the coeloblastula there are two layers of cells.
Additionally, the cells of the stereoblastula are undifferentiated while the cells of the coeloblastula are already beginning to differentiate into specific cell types. Furthermore, the stereoblastula is the earliest stage of embryonic development while the coeloblastula is a more advanced stage.
In conclusion, the difference between a stereoblastula and a coeloblastula is that the stereoblastula is the earliest stage of embryonic development, is comprised of a single layer of undifferentiated cells, and is surrounded by a protective membrane, while the coeloblastula is the more advanced stage of embryonic development, is comprised of two layers of cells that are beginning to differentiate and form specific cell types, and is not surrounded by a membrane.
Stereoblastula v/s Coeloblastula
| S.No. | Stereoblastula | Coeloblastula |
| 1. | The blastula is either without or with a very small cavity in the center | A spacious cavity either centric or eccentric is present |
| 2. | The cells are large and small in number | The cells are small but large in number |
| 3. | The cells are densely packed | The cells are not densely packed |
