Mosquito Fern or Azolla is a small free-floating fern approximately 1 to 3/8 inches wide. Leaves of the mosquito fern overlap giving a quilted look to the surface and hide the stem. A single root protrudes from each stem. Mosquito ferns can vary in color from green to red and are generally found in quiet ponds protected from wind action. Mosquito ferns can be aggressive invaders in quiet ponds and are often found mixed in with duckweeds or watermeal. If these fern colonies cover the surface of the water, then oxygen depletions and fish kills can occur. These plants should be controlled before they cover the entire surface of the pond.
Dense colonies of mosquito fern provide Habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called ?detritus?) for many aquatic invertebrates. Mosquito fern has no known direct food value to wildlife.