The fish zygote is meroblastic, meaning the early cell divisions are not complete. This type of meroblastic cleavage is called discoidal because only the blastodisc becomes the embryo.[1] In fish, waves of calcium released direct the process of cell division by coordinating the mitotic apparatus with the actin cytoskeleton, propagating cell division along the surface, assists in deepening the cleavage furrow, and finally heals the membrane after separation of blastomeres.[3]