The Semiceli are one of the domains on Calida. They have many unique traits not only next to Earth organisms, but also next to organisms on Calida. Although almost all multiceli have retained amoeboceli in some way, these cells are an integral part of the anatomy of virtually every Semiceli.
Amoeboceli are the analogue of Earth stem cells. However, amoeboceli almost always stay present during the entire life cycle of Calida organisms, meaning that very complex organisms have the ability to regenerate at an alarming rate, and in the case of the Semiceli, they can even reproduce asexually and survive as individual celus. Celi of the same species can even join together to make it's macroscopic form. This freedom the amoeboceli have make the semiceli practically indestructible. Really the best way to think of them is as extremely complex and organized sponges.