<span>Tight junctions, at the site of a tight junction, cells are held tightly against each other by many individual groups of tight junction proteins called claudins, each of which interacts with a partner group on the opposite cell membrane. For example, the tight junctions between the epithelial cells lining your bladder prevent urine from leaking out into the extracellular space.</span>
Answer: These animals eat algae in the water.
Explanation: They clean the water in other words.
