Are All Sponges Spongy?

Sponges are animals that live in oceans, lakes, and rivers. There close to 10,000 sponge species described by scientists, but far more await discovery! However, not all sponges look feel like their kitchen-sink cousins. Over time, have evolved into many sizes shapes, giving us the huge diversity of on Earth today. For example, rock-hard! These rock use minerals silica (glass) build skeletons—instead bone ours. Other unique ways eat. Most filter water get food, certain carnivorous, meaning they eat meat, including tiny shrimp-like creatures. Sponge with different body skeleton shapes can thrive very environments.