Aquatic Sowbug or Isopod

The isopod is a scavenger that uses its seven pairs of legs to move around the bottom of streams and ponds feeding on dead plants. It breathes through gills located on its belly. The isopod's eyes are very sensitive to light; therefore, it is usually active only at night. The darkness also helps it hide from the watchful eyes of its enemies. An isopod can live in water with low oxygen typical of water polluted with sewage or farm runoff. If you find many of these animals, what does that tell you about the quality of the water?