What role do archaeocytes play in animal sponge regeneration?

Archaeocytes, often referred to as amoebocytes, are essential to the remarkable regenerative capacity of sponges. These amoeboid cells are scattered throughout the mesohyl and possess the unique potential to transform into various other cell types, allowing them to facilitate the restoration of damaged or lost parts.1

When a sponge is dissociated into individual cells, archaeocytes play a critical role in the formation of active aggregates that eventually reconstitute a functional, growing sponge. During periods of unfavorable environmental conditions, sponges may reduce themselves to small fragments consisting primarily of masses of archaeocytes protected by layers of pinacocytes; once favorable conditions return, these fragments are capable of developing into complete, adult sponges.2

Additionally, archaeocytes are central to the process of gemmulation, a form of asexual reproduction. They accumulate reserve food granules to form gemmules, which serve as survival structures. When conditions improve, these gemmules germinate, and the archaeocytes emerge to differentiate into the various cell types necessary to grow a new sponge.3