Anemonefish and sea anemones have a symbiotic , mutualistic relationship, each providing a number of benefits to the other. The individual species are generally highly host specific, and especially the genera Heteractis and Stichodactyla, and the species Entacmaea quadricolor are frequent anemonefish partners. The sea anemone protects the anemonefish from predators, as well as providing food through the scraps left from the anemone's meals and occasional dead anemone tentacles. In return, the anemonefish defends the anemone from its predators, and parasites. The anemone also picks up nutrients from the anemonefish's excrement, and functions as a safe nest site.The nitrogen excreted from anemonefish increases the amount of algae incorporated into the tissue of their hosts, which aids the anemone in tissue growth and regeneration. It has been theorized that the anemonefish use their bright coloring to lure small fish to the anemone, and that the activity of the anemonefish results in greater water circulation around the sea anemone. Studies on anemonefish have found that anemonefish alter the flow of water around sea anemone tentacles by certain behaviours and movements such as "wedging" and "switching." Aeration of the host anemone tentacles allows for benefits to the metabolism of both partners, mainly by increasing anemone body size and both anemonefish and anemone respiration.