They Came From the Lake
by Tim Smith
Odd-looking gelatinous blobs are appearing in some Missouri lakes and ponds. I’ve been contacted twice in the last week by persons observing them and wondering what they are. They may remind you of the jellyfish that you have seen in the ocean. There is nothing to fear from these colonial, invertebrate animals called bryozoans . They are from this world.
Most bryozoans live in saltwater environments and they build stony skeletons similar to those of corals. There is one group of bryozoan species that live in freshwater habitats, including Missouri’s lakes, ponds and streams. Worldwide, bryozoans are found on every continent except Antarctica.
The tiny (about one millimeter long) individuals in a colony, called zooids, are filter feeders. They extract plankton, bacteria and detritus from the water and help to recycle nutrients in the water. Their colonies can form gelatinous masses as large as basketballs, although they typically are closer to the size of a softball. Colonies may be found free-floating or attached to submerged rocks, dock supports, logs, plastic debris or vegetation.
Bryozoans can reproduce by several methods. They can form small structures, called statoblasts, which are easily transported to new water bodies by waterfowl. The statoblasts can remain dormant for years and become active again when conditions are good for growth. Colonies can also reproduce by pinching off portions of their gelatinous, zooid-containing material that can grow into another colony.
Although strange-looking, bryozoans are harmless and their presence usually indicates good water quality, as they are intolerant of pollution or muddy water. They can become a nuisance only if they attach to the inside of pipes or filters and impede the normal flow of water.
July 12th, 2009 at 9:30 am
While at Little Dixie Lake in Millersurg on July 11, 2009 saw two of these.
July 13th, 2009 at 8:00 am
We saw one of these this weekend at the Lake of the Ozarks and couldn’t figure out what they were. We all had our guess as to what it was but no one was close!
July 14th, 2009 at 3:55 pm
back in the early 90s these things were all over the eagle rock part of table rock lake. i was diveing alot at that time and saw thousands most the size of basketballs and was attacht to trees
July 15th, 2009 at 6:15 am
I can hardly wait to go swimming in my lake south of Clinton this weekend to see if I have any!
July 17th, 2009 at 5:26 am
Shapes are similar to jellyfish, I often see the animals in the lake Kelimutu in the area Flores, Indonesia.That’s animals are often captured to be a mixture of drugs.
July 25th, 2009 at 9:59 am
My son just got back from church camp in Tyler, Texas. The highlight of his camp experience was swimming with a blob in a pond. How ironic?
July 31st, 2009 at 12:59 pm
We found a ton on these off our dock in Lake Waukomis. We’ve been calling them “Alien Eggs”… We had no idea they were actually animals. Crazy
September 7th, 2009 at 7:25 pm
We found a few at Three-Mile Lake in Paw Paw, Michigan. I brought one home to show my students, and we will examine it under a microscope. They will love it…I think.
September 11th, 2009 at 1:19 am
We found one this evening at Mark Twain Lake – it was similar in size to a rounded football, brownish in color, had several “mouths” or openings (about the size of a quarter), felt slimy on the outside, yet firm when I lightly pressed on it. It was free floating. Also, there were two smaller ones attached to an old concrete bridge abutment. We were very careful in the handling of it, assuming it was a living creature. My internet research lead me to this site. I have enjoyed others’ comments.
September 15th, 2009 at 7:09 pm
My son and I have been trying to figure out what we had in the pond. They have been showing up for about 5 years in our pond. We have some the size of 2 to 3 basketballs. most are attached to trees or sunken branches. We found it funny that Roman had been calling them alien eggs. We labeled them alien eggs also. They reminded me of the movie the body snachers. Was hoping for grumpy neighbor to change personality.
Just kidding!!!!!
October 29th, 2009 at 5:04 pm
Hi,
I agree that Bryozoans can reproduce by several methods. The statoblasts can remain dormant for years, this is right.
Roni