Nobody likes being on the bottom rung of an ecosystem, but somebody has to do it. And in the Bone River and Bone Swamp, this job falls to the mud-swarmer. The mud-swarmer's beak has narrowed, allowing the fish to dart away from predators like the bearhog plent or the sledodil. Because of their smaller size, mud-swarmers have begun to move in schools of twenty to forty. The colorful red fin on the mud-swarmer has begun to grow darker and less noticeable, which helps the mud-swarmer hide from predators a little bit better.