Final answer:
The whitefish blastula is a stage of development in the early embryo of a whitefish. It is composed of one layer of cells with a hollow space in the center called the blastocoel. The cells in the blastula rapidly undergo mitosis to subdivide the embryo into smaller blastomeres.
Step-by-step explanation:
The whitefish blastula is a stage of development in the early embryo of a whitefish. It is composed of one layer of cells with a hollow space in the center called the blastocoel. The cells in the blastula rapidly undergo mitosis to subdivide the embryo into smaller blastomeres. The blastula stage is followed by gastrulation, where the cells move inward to form an inner cavity called the archenteron.