Leucone

A leucone is a type of sponge body plan organization, characterized by a complex system of choanocyte chambers. These chambers, lined with flagellated choanocytes, are not directly adjacent to the spongocoel. Instead, they are interconnected by a network of canals. Water enters the sponge through numerous small incurrent pores (ostia), travels through these canals, and enters the choanocyte chambers where food particles are filtered out by the choanocytes. Filtered water then exits the choanocyte chambers through excurrent canals and eventually exits the sponge through one or more oscula.

Leuconoid sponges exhibit the most complex organization among the sponge body plans (asconoid, syconoid, and leuconoid). This increased complexity leads to a larger surface area for filtering water, making leuconoid sponges generally larger and more efficient filter feeders than asconoid or syconoid sponges. Because of their efficiency and structural complexity, the vast majority of sponge species exhibit the leuconoid body plan.

The leuconoid structure allows for a greater degree of specialization and flexibility in the sponge's form and function. This type of body plan has allowed sponges to inhabit a wider range of environments and grow to larger sizes. The decentralized arrangement of choanocyte chambers also provides the sponge with greater resilience to damage, as a single blockage in one chamber does not necessarily affect the function of the entire organism.