Sea sponges lack the ability to move, so most of them stay still at the same place, forming reefs. A reef is often formed of several species of sea sponges, or it may even include coral or other formations. A sea sponge animal has to live their lives amongst all other marine animals that live in the same area. Some sea sponges are also known for getting involved in the process of photosynthesizing endosymbionts, where they produce three times more oxygen than they take in. Hence, the oxygen that they produce benefits the organisms living beside them. Some shrimps also live in loggerhead sponges giving them protection against other predators.