Schizocoelic

Schizocoelic refers to a type of coelom formation found in some invertebrate animals, particularly in protostomes like annelids and mollusks. The coelom, which is the fluid-filled body cavity, develops from splits within the mesoderm. The mesoderm is one of the three primary germ layers of an embryo.

In schizocoely, the mesoderm arises from cells located near the blastopore, which is the opening of the archenteron. These mesodermal cells then proliferate and form solid masses. Subsequently, a cavity forms within these mesodermal masses through a process of splitting or cavitation. This developing cavity is the coelom. This method of coelom formation contrasts with enterocoely, where the coelom arises from outpocketings of the embryonic gut.

Schizocoelous development is characteristic of many phyla within the Lophotrochozoa, a major group of protostomes. Understanding the mode of coelom formation is a key feature used in animal classification and in tracing evolutionary relationships.