Why can animal sponges have vase-shaped tube-shaped or branching forms?

Sponges exhibit diverse external appearances, including vase, tube, and branching forms, which are primarily influenced by factors such as age, environmental conditions, and food supply.1

While these shapes vary greatly, they are fundamentally tied to the sponge's water-current system. Sponges are filter feeders that rely on a complex network of canals and chambers to circulate water, which delivers oxygen and food particles while removing waste. The movement of water is maintained by the flagella of specialized cells called choanocytes.32

Because sponges lack true organs, their structural diversity—ranging from amorphous encrustations to complex, erect, or tubular shapes—reflects their adaptation to different habitats and their need to optimize this water-flow process for survival.314