Monday, September 4, 2017

Magnificent Bryozoan



Day 326: This is a colony of Magnificent Bryozoans (Pectinatella magnifica). Yes, that's really the name of the organisms which form this gelatinous underwater mass. I would imagine (I would hope!) that some of you are opening your mouths and/or limbering up your fingers to ask, "A what? What's a bryozoan?" The word translates as "moss animal," and that pretty much says it in a nutshell. Although they could easily be mistaken for a coral or blob of algae, these creatures (zooids) are filter-feeding aquatic invertebrate animals. Seen singly, they resemble tiny sea anemones. A colony begins when a single zooid buds to reproduce genetically identical copies of itself asexually. As the colony matures, the reproductive process converts to a sexual one. Large colonies such as this one are a mosaic of smaller colonies (each with its own individual genotype) which must merge before their gelatinous exoskeletons harden. The Magnificent Bryozoan is unusual in that it occurs in fresh water (most bryozoans are marine). They are native to North America and to the Pacific Northwest, although until recently, they were considered rather rare here.

I encountered my first Magnificent Bryozoan colony in Swofford Pond two years ago. I had no idea what I was seeing, and quite honestly, I was rather repelled by the great gobs of goo I saw floating just below the surface of the lake. I made some inquiries and found out that these creatures are becoming more prevalent in our lakes, and some scientists believe that this is due to a rise in water temperatures. I am inclined to agree. During my September Morn paddle, I encountered HUNDREDS of colonies along the west edge of the Tilton Arm where it debouches into Mayfield Lake. Most were attached to submerged logs and branches, but a few were free-floating.

Magnificent Bryozoan colonies are large (up to two feet across) and surprisingly firm, if reports are to be believed. Thank you, I will admire this life-form from the 'yak. I feel no compelling need to lift one out of the water for the sake of science.

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