They’re Alive! Are these brain-like blobs growing in a pond near you?

Sam Leininger

7 years ago

A reality stranger than fiction

Straight out of a script from a classic 1950s horror film, a local pond is mysteriously overtaken by multitudes of gelatinous brain-like blobs. These blobs appeared, seemingly overnight to dominate a pond, causing immediate concern from the affected landowner. It is not hard to imagine that if you found these strange creatures lurking in the pond behind your house, you might wonder whether you should be running for hills.

Bryozoan Colony

Who ya gonna call?

If you were faced with an invasion of brain-like blobs, who would you contact? Do you call out the Army or the National Guard? How about the Ghostbusters? In this case, the Conservation District was contacted by the affected landowner. They were concerned that these large blobs may be “egg masses” from invasive bullfrogs. With some of the “egg masses” being more than two feet in diameter, it was clear that this was either one really big frog, or something else was going on.

Upon inspection of photos of the creatures, WeedWise Manager Sam Leininger was able to identify the blobs as being a cryptic species known as a Magnificent Bryozoans (Pectinatella magnifica). These bizarre creatures are also known as moss animals that grow into these strange blob-like gelatinous colonies.

bryozoan staoblasts

Digging Deeper

The landowner is obviously concerned about the bryozoans. Unfortunately, very little is known about these bizarre creatures. Although they are known to occur in freshwater environments across much of the eastern United States, they have only been documented in Oregon since 1998. A little research revealed that these strange-like creatures are colonies of tiny filter feeding animals. These bizarre creatures also form tiny seed-like propagates known as statoblasts. These statoblasts can apparently withstand extreme cold and drying and can spread very easily with hook-like structures on their exterior. So not only are the bryozoans taking over the pond, but they can apparently be transported relatively easily from one water body to another.

A follow-up consultation with our local Oregon Department of Fish and Wildlife Biologist and the state Aquatic Invasive Species Coordinator, yielded little additional information. An additional consultation with a former US Fish and Wildlife employee that had been tracking these bryozoans in the Pacific Northwest only further confirmed our lack of understanding regarding these bizarre animals. The stark reality of is that we simply know very little about the origin, distribution, or impact of these creatures.

So how do we go about killing these alien brain-like blobs?

With so little is known about these species, it is hard to determine proper control practices. More importantly, we should be asking whether we should control them at all. Although the bryozoans are strange and foreign, and may in fact be a new invader to our area, they may just as likely be a rare or poorly documented native species. In fact, they may be a desirable native component in need of conservation and additional study.

Because the jury is still out on these creatures, the WeedWise program recommended not removing the colonies, but also to avoid distributing them further. We suggested that the landowner be very careful to clean any material that may be exposed to the water in the pond and to avoid distributing the seed-like statoblasts.

Filling in the gaps

To help improve our understanding of these bryozoans, Sam spent some time documenting the population. He submitted a report to the USGS Nonindigenous Aquatic Species database to help increase our understanding of these species and document populations here in Oregon. Any reports of byrozoans can also be submitted to the Oregon Invasive Species Hotline to immeidately connect you with biologists interested in understanding the distribution of these amazing creatures.