Sponges are similar to animals because they have specialized cells to perform specific tasks, lack cell wall within the cells, and are heterotrophic (eat other organisms to get food), just like animals.

Water plays vital role in sponges. Water carries nutrients, such as organic debris and microorganisms, when it enters the sponges and carries out waste when it exits. In addition, water spreads sponges’ eggs and sperms, so that the sponges will be spread out.

**Sponges** are the simplest and the most intriguing animals on the earth, these species are placed under Phylum Porifer because these organisms have tiny openings or pores located all over their bodies. These organisms are sessile, meaning they do not move or use locomotor organs.

In harder sponges, the skeleton composed of pointy spicules that are harden by addition of calcium carbonate. In softer sponges, the skeleton consisted of spongin, which are long flexible protein fibers.

Water plays vital role in sponges. Water carries nutrients when it enters the sponges and carries out waste when it exits. Water is main resource for their respiratory, circulatory, and digestive system. In addition, water spreads sponges’ eggs and sperms that are essential for reproduction. Without continuous flow of water, they cannot survive.

See explanation.