Weird Things

by Dr. Jerry Skinner, Woodbourne Preserve Resident Naturalist

August 12, 2006

It’s the time of year when the calls start coming and jars of peculiar things start showing up at my office at Keystone College. 

“Weird Things are appearing in my lake!”  “What is this thing?”  “Can this hurt me?  Is it dangerous?”  These are the usual questions.

It is in August as waters warm that often overlooked creatures grow large enough to be seen by swimmers, boaters, and fishermen.

Weird Thing #1was a jar brought to my doorstep with a quarter-sized jellyfish in it.  It was one of hundreds seen swimming about in a pond in northern Lackawanna County.  They’d never been seen there previously, but now the water was thick with them.

The identification was easy because there is only freshwater jellyfish in the US, Craspedecusta sowerbii which was probably introduced from Europe in the early 1900s.  Like its relatives, it feeds using stinging cells to capture microscopic prey.  Can they sting people?  Personally, I’ve never had a problem handling them, but I’m not sure I’d go swimming into a swarm of them!  We can only guess how this rare creature made its way to this isolated pond in Covington Township.  Dr. Terry Peard at Indiana University of Pennsylvania studies Craspedacusta and has a website at http://www.jellyfish.iup.edu/ where you can learn more and report sightings.

Weird Thing #2 required a bucket to carry it.  It was a basketball-sized ball of hardened gelatin that had come from a pond in Dimock Township, Susquehanna County.  My friend was amazed to learn that it was a living colony of animals known as bryozoans.  They are completely harmless and having them in his pond may be seen as a sign of good water quality because these filter-feeders don’t do well in turbid water.  I see them most often in fairly clear, undeveloped ponds.  They are usually attached to a branch in the water close to shore.  Sometimes large ones break off and float at the surface.

A field trip to a stream at Woodbourne Forest & Wildlife Preserve in Susquehanna County turned up Weird Thing #3, freshwater sponges.  They were growing on the underside of many rocks in the water.  Most folks don’t know that some sponges live in freshwaters in PA.  This one was tan although many are green, harboring algae in a symbiotic relationship.  I always smell a suspected sponge to confirm its identity.  Lacking defenses such as spines or teeth, sponges resort to chemical warfare for protection, making an array of noxious chemicals that leave it unpalatable and with a distinctive odor.

I’ve always enjoyed it when someone brings an oddity to me.  One of my professors at Ohio State University told me that if I wanted to be a real aquatic biologist, I should know everything that might be found in the water.  I took those words to heart.  So keep them coming…I haven’t been stumped in a while.