Plumatella is the largest and most common group of freshwater bryozoans. The name, “bryozoan,” meaning “moss animal,” aptly describes most plumatellid bryozoans whose appearance sometimes resembles brown moss.

Key characteristics include:

• Tentacles arranged in a double U shape;
• Tubules containing free oval capsules, usually buoyant;
• Tubules in biofouling situations often fused together.

Asexual reproduction in plumatellids involves dormant, egg-like “statoblasts” less than 0.5 mm long. These are normally dormant for one to six months, capable of surviving extreme temperatures, toxins, low oxygen, and other unfavorable conditions. Both sessile and free statoblasts are produced. Sessile statoblasts are cemented to the substratum and may be difficult to dislodge; buoyant statoblasts are often picked up on the feathers of waterfowl and transported to new locations.

Sexual reproduction results in a swimming "larva," actually a motile colony in which one to four zooids are surrounded by a ciliated mantle. Released by the colony, usually after sundown, this non-feeding larva may swim freely for up to 20 hours. In settling, the larva adheres to the selected substrate and the ciliated mantle peels away. Within 30 minutes the new lophophores are extended for feeding and colony growth by zooid budding begins.