Home Uncategorized Jellyfish a harmless, rare sight at area water bodies

Jellyfish a harmless, rare sight at area water bodies



NASHVILLE – Many lakes around the local area are home to freshwater jellyfish.
According to Professor of Biology at Henderson State University, James Engman, the freshwater jellyfish we find in Arkansas is the Craspedacusta Sowerbii. This jellyfish was spotted in Lake DeGray around this time last year, so it is likely that a current visitor to DeGray may also get the opportunity to observe one.
Having been a park ranger at Dierks Lake for four years and a current ranger at Lake Greeson, Devin Flemens has seen his fair share of these aquatic creatures. Flemens said they are translucent and look white or light green in the water. An observer may compare them to tiny umbrellas.
Awareness of these multi-cellular organisms is not common because they are small in size and not harmful. A casual swimmer may not even notice them. “They are about the size of a penny or nickel. They do have stinging cells, but they are too small to penetrate human skin,” said Flemens.
The Assistant Chief of Fisheries Management with the Arkansas Game and Fish Commission, Ben Batten, said that the jellyfish are not from the United States, but are indigenous to the Yangtze River Valley in China. They were first discovered in the United States in the 1880s, through accidental introduction.
Batten claims that the creature, in polyp form, was transported to the Philadelphia area on decorative plants from China.
Polyp form is the first form of the many life stages of the jellyfish. When in polyp form, they are attached to the ground or a rock and are nonmoving. Batten says they can stay in this shape for up to four years waiting for conditions to be suitable for bloom.
According to Batten, suitable conditions depend on the amount of algae in the body of water and the water temperature. They usually bloom in the hottest months of the year – mid to late summer- when algae plants are plentiful. When appropriate underwater circumstances are met, all the polyps bloom at once and create a large outpouring.
According to Batten, the size of the jellyfish after bloom ranges from 5-25 millimeters in diameter. The life cycle of the creature after bloom tends to be short.
Like saltwater jellyfish, freshwater jellyfish do have tentacles, but they are too small to sting humans.
The hydromedusae reproduce through asexual reproduction and eat algae, phytoplankton (microscopic plants), and zooplankton (mini crustaceans), said Batten.
The jellyfish have been documented in 57 locations in Arkansas, many locations having yet to be documented, said Batten. A few lakes in the area that are home to the jellyfish are Lake Ouachita, Lake Greeson, Lake DeGray, and Dierks Lake.
The existence of the animal commonly goes unnoticed because they “do not have a major effect on the environment,” said Batten.
Batten considers the underwater animals a “novelty because they come and go every few years.”