Watching the Foul and the Loathsome

WATCHING THE FOUL AND THE LOATHSOME
 September 06 & September 08

About this time some years ago, a Belleville resident dropped by at the Quinte Conservation office with an object that he had found in the Moira River, right within the city. His curiosity was quite understandable as the object we were now staring at in the plastic pail was semi floating in the water like some creature from a horror movie. It was the size of a basketball, round and translucent, somewhat textured, but so slimy as to defy touching. Finally, it was I who volunteered to close my eyes and gently lift the object from the water for a closer look. As a dairy farmer from way back, my hands had already experienced many questionable textures, and had probed numerous dark recesses where most hands seldom venture. The gelatinous object I now held in my hand was attached to a decaying piece of vegetation and trembled noticeably as I rotated it for some clue as to what it might be. The sensation was not unlike holding a quivering ball of Jell-O, the only difference being, that it was decidedly sticky.

A little research and I was soon able to give the object a name, at least, but still had a long way to go before I fully understood what it was, and how they functioned. Since that memorable day, I have encountered them in several areas including Fourth Depot Lake and the Napanee River east of the Colebrook Dam. They are called Bryozoans and are actually aquatic organisms, but are classified as animals. Some of us know them better as “moss animals.” These little aquatic organisms live in colonies of interconnected individuals forming masses such as we have found in recent years. Sometimes they float freely, other times they attach themselves to rocks, or to plant material in the water. One large cluster of Bryozoans was found a few years ago attached to a dock at Wellers Bay.

The Bryozoans that turn up at this time of the year are mostly the soft and gelatinous variety, but they do occur as tufted leaf-like fronds or even hard calcified skeletons, not unlike coral. Almost all Bryozoans are colonial, composed of anywhere from a few to millions of individuals. The one I held in my hand likely contained millions of individuals, all amassed to form the globulus gel I pulled out of the pail. Although an animal they don’t really move around, although some species do to a certain degree.

How do they reproduce? Bryozoans are able to propagate both sexually and asexually, the latter occurring by budding off new zooids (individual functioning units) as the colony grows. If a piece of the colony breaks off, this piece can continue to grow and form a new colony. Most are hermaphroditic – that is, individuals possessing both ovaries and testes. Some shed both eggs and sperm into the water where they fuse, but the majority brood their eggs in tiny chambers, capturing free-swimming sperm with their tentacles to fertilize the eggs. The eggs divide, develop into free-swimming larvae, escape from the brood chamber, and swim away to settle on an object somewhere to metamorphose into a new zooid, thus starting a new colony. Of course, we can’t see this unless we were to somehow view the whole process under a microscope. All we get to see is the mass of millions that have united to form something we can observe floating in the water – or hold in our hand, for those who dare to experience the sensation.

At first glance, Bryozoans superficially appear to have more in common with coral, but Bryozoans and corals belong to quite different phyla and are unrelated. A glob that we may find is actually a colony of zooids, not polyps as in corals. And each of these zooids has whorls of delicate feeding tentacles gently swaying in the water catching food. Bryozoans feed on minute organisms, including diatoms and other unicellular algae. In turn, they are fed upon by grazing organisms such as small fish and are subject to competition from algae. Who knows what daily routine in their lives we interrupt by lifting specimens out of the water. And these little critters have been around for awhile. They have a fossil record extending back some 500,000,000 years, to the upper Cambrian period.

Identifying a mass as a Bryozoa (or plural Bryozoan since there are millions of them in one cluster) is enough for us. To identify the exact species would be a painstaking job as there are about 5,000 living species in the world. And in some cases, they can be down right nuisances as they often clog water intakes. Yet, they produce an incredible variety of chemical compounds, some of which may possibly find uses in modern medicine. As an example, one compound produced by a marine species of Bryozoa, the drug bryostatin 1, is currently under serious testing as an anti-cancer drug.