Image from Gippsland Coastal Board

There are over 5000 species of sponges with a large majority of them being marine. All sponges are members of Kingdom Anamalia and they are invertebrates. Sponges are the simplest froms of animal. Their bodies are asymmetric and different cells perform different functions but they do not have any specialized tissues or organs. They lack muscles, nerves, and organs as well as organ systems.

Sponges come in many shapes and sizes including some as small as one millimeter and others as large as elephant ears. Sponges are sessile so they cannot pursue food which forces them to be filter feeders.

Image from Palaeos