 Thank you for the creative
descriptions. It's not often people describe things to me in terms of "the size of a raccoon." You
have described a bryozoan which can range in size from a tennis ball to a muskrat up to apparently
even a raccoon. Seriously, this is the third bryozoan report that I have had this summer, which is
probably due to the low and clear water conditions that we have seen around the state due to the
drought. They've always been there but now they are more visible to people.
Bryozoans are animals related to jellyfish and other primitive invertebrates. The animal itself
is actually a colony of many individual bryozoans. The green color is due to the algae that also
colonize the bryozoans. In fact just the name itself gives a clue as to the relationship between
these two organisms; "bryo" refers to plant and "zoan" refers to animal. Bryozoans are usually
attached to the substrate, often around submerged twigs or sticks. Sometimes they break away and
then may settle wherever they come to rest. Breaking the colony up can result in new budding and
growth and result in new colonies forming. They eat microscopic plankton and protozoans.
This animal is so unique it is classified in its own phylum. So, what you have seen has been
around all along but now you know the rest of the story. Its nice to hear that you were on the river
with your kids and now they have an opportunity to add to their knowledge of the river and aquatic
life. Thanks for your inquiry.
Andrew L. Shiels
Nongame and Endangered Species Unit
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