A
spongocoel () is the large, central cavity of
sponges. Water enters the spongocoel through hundreds of tiny pores (
Ostia) and exits through the larger opening (
osculum). Depending on the body plan of the sponge (which can be
asconoid, syconoid, or leuconoid), the spongocoel could be a simple interior space of the sponge or a complexly branched inner structure. Regardless of body plan or class, the spongocoel is lined with
choanocytes, which have flagella that push water through the spongocoel, creating a
current.