The Crawford Park District invites you to come out to Lowe-Volk Park. The freshwater jellyfish are once again swimming in the Lowe-Volk Park pond. First observed a couple of years ago, the small, bell-shaped jellyfish, known as hydromedusae are five-25 mm in diameter (about the size of a nickel). They are translucent with a whitish or greenish tinged X on their body. Freshwater jellyfish have four very long tentacles which give stability for swimming and shorter tentacles to facilitate feeding.

The total number of tentacles varies from 50 to 500. Like most jellyfish, hydromedusae have stinging cells for stunning prey. Freshwater jellyfish apparently do not sting humans because the stinging cells cannot penetrate human skin even though some have claimed otherwise.

Freshwater jellyfish originated in China. They were first discovered in the U.S. in 1880 and have been recorded living in 44 states. They are most commonly seen in August and September when the waters are warm and food is plentiful. They are easy to see with the naked eye, especially on sunny days. They will rise to the surface in large numbers called "blooms."

Jellyfish eat tiny, microscopic animals called zooplankton that are found throughout the water. Freshwater jellyfish appear in a range of aquatic habitats. They are most commonly found in shallow, slow moving or stagnant artificial bodies of water. They have occurred in large river systems (Allegheny, Ohio and Tennessee River systems), natural lakes, and ornamental ponds. They also can be seen in Lake Erie and the surrounding islands.

Some scientists believe that the resting bodies, called podocysts, are one way in which the jellyfish are transported from lake to lake. It is believed that the podocysts may be transported on aquatic plants, by aquatic animals, or perhaps on the feet of birds. When conditions become favorable, the podocysts develop into polyps, and the life cycle is continued.

The appearance of the jellyfish is described a sporadic and unpredictable. They will appear in a body of water even though they were never reported there before. The following year they may be absent and may not reappear until several years later. Don't miss your chance to see freshwater jellyfish. Come visit Lowe-Volk Park's handicap accessible fishing dock. If it's a sunny day, you just might peer down into the water and see a jellyfish swim to the surface.

For more information or to contact the park district office, call 419-683-9000.