SpongePorifera

Sponges are multicellular marine animals varying significantly in form, colour, and size. Their bodies are perforated by numerous pores and channels, allowing for constant water flow through their structure. They appear as encrusting mats, massive irregular growths, branching forms, or distinctive cup and tube shapes. Colours often include shades of red, orange, yellow, purple, and brown. Individual sponges range in size from a few centimetres to over 1 meter (3.3 ft) across. Most species are firm or somewhat elastic to the touch, owing to an internal skeleton of mineral spicules or flexible spongin fibers.

Sponges are sessile, attaching to hard underwater surfaces from shallow reef crests down to over 100 m (330 ft) on reef walls and slopes. They are abundant throughout coral reefs and frequently observed by divers. Most sponges feed by filtering bacteria and microscopic particles from the water column. Some host photosynthesizing microorganisms, which contribute to their nutritional intake.