Marine sponges are sessile animals that look like plants. They attached themselves to a rock, shell or seafloor when they are young and there live for the rest of their lives. They filter water through their porous body for the food they eat. Marine sponges are natural bath sponges (with living cells removed) that we all are familiar with. They actually are the oldest and simplest animals that have been living on earth for millions of years. There are various types of sponges under Phylum PORIFERA. They grow in every ocean in the world regardless of extreme temperatures. They can be found hundreds of meters under sea level but mostly are found in 5-50 meters deep. Marine sponges are filter-feeding animals because all adult sponges are sessile and can’t move around benthic surface. For approximately 20 centimeters sponge can filter up to 2000 liters of seawater during one day. “As filter feeders, sponges efficiently take up nutrients like organic particles and microorganisms from the seawater, leaving the expelled water essentially sterile.” Marine sponges have no true tissues or organs, just constructed with layers of cells even without nervous system. Inside the sponge, the vibration of ciliates, the special cells circulate seawater through small pores and absorb planktons and small sea organisms. Marine sponges come in different but striking colors, bright red, purple, yellow, and brown, etc. These colors and some are toxic as well may help them defend from sponge eating invertebrates and some fishes. Some other small marine organisms, fishes, and microscopic organisms often call marine sponges their homes. Sponges often have skeleton of spicules, which protect and give refuge to small invertebrates from other marine scavengers.