Max Size: 20 cm (8 in)
Habitat: Rocks, piles, and shells.
- Sponges are one of the oldest, simplest forms of animal. They lack tissue layers and complex organs that we tend to associate with animals
- Many sponges have glass (silicate) spicules within their tissue to provide structural support. These look like little needles or stars
- Sponges filter feed constantly using collar cells (cells with a flagellum and a structure called a collar). Collar cells use their flagella to generate currents that draws water into the sponges pores, where plankton and other tiny particles are collected as food