Ponds exist as their own complex ecosystems, allowing for a multitude of plants, animals, bacteria, and other organisms to thrive. One of the most illusory and confusing is the Magnificent Bryozoan (Pectinatella magnifica), which may look like a strange balloon or a xenomorph egg to those uneducated of what they truly are. Bryozoans are unique creatures in their form, function, and lifecycle within a pond. While not common, Magnificent Bryozoans can be seen in a variety of pond sizes. They offer benefits to a pond’s ecosystem and can generally be seen as a good sign of your pond’s health.
Bryozoans are colonial creatures, meaning they are a larger organism made up of smaller organisms. Individual parts of a colony are known as Zooids, a free-floating organism like freshwater zooplankton, that can be a maximum of 4 millimeters wide (Pinnix 2023). As Zooid’s bump into each other, they start to form a colony where they build a calcium carbonate structure with a gelatinous body in-between. Once this structure is made, colonies will group together to make the larger Bryozoan body, which can grow up to 2 feet (60 cm) specifically for Pectinatella magnifica (Daniel, 2024). This larger body structure is transparent to brown in color and attaches to sticks, logs, rocks, docks, etc. keeping the body just under the surface of the water. Reproduction of Bryozoans can occur both sexually and asexually. Asexually the Bryozoan can bud/break off a Zooid to form a new colony or use stratoblasts (cells with a hard covering to protect from harsh environmental conditions) that will eventually grow into an individual Zooid (Koth, 2018).
Magnificent Bryozoan’s are known as filter feeders within their food webs. Each Zooid within a Bryozoan has a horseshoe shape of tentacles that capture algae, diatoms, zooplankton, and other suspended organic material. In the process of filter feeding the water clarity can increase due to suspended clay and silt being removed from the water column. A single zooid can filter up to 8 millimeters of water a day, with several hundred to thousand being present in a colony (Pinnix 2023). Magnificent Bryozoan’s are commonly found in lakes, ponds, and other relatively slow-moving bodies of water due to their feeding style but can still survive in streams. Magnificent Bryozoan’s are also considered a warm water species with a temperature tolerance between 4-32 C (39.2-89.6 F) (Daniel, 2024).
Due to their harmless nature, key filter feeding abilities, and removal of specific organisms within the water column, Bryozoans are seen as a beneficial aspect of a pond’s ecosystem. Their ability to filter out bacteria, algae, and protozoa can help prevent eutrophic blooms of these organisms. Additionally, Bryozoans act as food for other organisms within the system like snails, insects, and fish (Koth, 2018). Bryozoans may be a nuisance if blocking inflow/outflow pipes and should be relocated to another part of the pond if so. When treating a pond, chemicals should be used with precaution as bryozoans are easily susceptible to many algaecides and herbicides used.
Bryozoans are a very unique part of freshwater bodies. If you’re lucky enough to find one in your pond, take it as a sign of how good your waterbody’s quality is. Understanding how they can interact with other organisms of your pond will help you cultivate a healthy and balanced ecosystem. Bryozoans are also sensitive to temperature and environmental changes which is why if one is found you should enjoy it while it’s alive and thriving. The ecological importance of Bryozoans and how they function in your pond is important for anyone who wants to make sure they’re correctly managing their pond.
Aaron Bailey
Aquatic Specialist
Cleveland, OH Branch