This slide shows several zooids of the freshwater ectoproct Plumatella.  Note the conspicuous lophophores.  These feeding devices consist of masses of ciliated tentacles borne on ridges surrounding the mouth.  In addition to reproducing by budding, freshwater bryozoans reproduce asexually by means of special resistant bodies called statoblasts (not visible on this slide).  These dark, disc-shaped structures (which are similar to the gemmules of freshwater sponges) are produced during the summer and fall, and can remain dormant until environmental conditions improve in the spring.