How can separated sponge cells reorganize into a functional sponge?

Sponges possess an extraordinary capacity for regeneration, allowing them to reorganize into functional organisms after being dissociated into single cells or fragments. This process involves several key stages:1

• Aggregation: Once separated—whether by mechanical or chemical means—the cells settle, migrate, and form active aggregates. This reassociation is mediated by selective cell recognition, where proteoglycan molecules in the extracellular matrix bind to species-specific cell-surface receptor sites, ensuring only cells of the same species reaggregate.12
• Diamorph Stage: To grow into a larger structure, these aggregates must attach to a surface. They flatten and develop an envelope of specialized cells called pinacocytes.1
• Reconstitution: Following the formation of this envelope, the sponge reconstitutes its internal canal system and choanocyte chambers.1

Unlike embryonic development, this process primarily relies on the sorting and rearranging of existing dissociated cell types rather than the differentiation of primitive cells. Archaeocytes play a particularly significant role in this reorganization, which remains a subject of theoretical interest regarding cell adhesion, movement, and recognition.1