(Click on the blue bar for each question to reveal the answer.)
Do freshwater jellyfish sting?
Can I raise freshwater jellyfish in my aquarium?
What is the recommended temperature, pH, and food supply for captive jellyfish? Can they reproduce in captivity?
What shape tank, lighting, and environment is preferable for a captive jellyfish habitat?
How can I catch freshwater jellyfish?
Is the appearance of the freshwater jellyfish related to water quality or the quality of fishing in a lake?
The matter of the jellyfish impacting the fishing is a complicated one to answer. The jellyfish could be having an effect on the zooplankton population on which some fish or fish larvae normally feed, thus affecting the growth of the fish or the overall size of the fish population. Some research has addressed this and related issues (see Jankowski and Ratte, 2000 and Jankowski, et. al. , 2005 in the References section of this website). In studies by Jankowski it was suggested that a decrease in some zooplankton could be correlated with an increase of medusa. There are, however, several impacting/interacting factors in the environment: size of pond, size and type of fish, timing of the fish-zooplankton-jellyfish populations maturing and interacting, zooplankton present, interacting food webs, etc. Another possibility is that the larger fish may be feeding on the jellies and therefore not interested in the bait or lures that are being used for fishing. I cannot verify this latter idea, since we have not observed fish eating jellyfish.
How can you tell if the jellyfish is male or female?
Can freshwater jellyfish harm small or young fish?
Do fish eat freshwater jellyfish?
How do freshwater jellyfish enter a pond?
Do freshwater jellyfish have any natural predators?
It is noted that the best way to preserve specimens for DNA analysis is in a jar of 70% isopropyl (rubbing) alcohol. What is the best way to preserve jellyfish for species identification?
Could you provide literature on or an annotated bibliography about freshwater jellyfish life history and distribution?
Where/what is the origin of freshwater jellyfish?
Another story that can be found in the literature is that they originated in South America and made their way to the U.S. in bilge water of ships. About the same time (late 1800’s), the polyp form was discovered in Tacony Creek near Philadelphia, PA. The records of the organism in the U.S. have been sparse over the years (perhaps leading to the belief that they were rare), although we do have verified sighting information from most states.
Please also see the distribution section of the website.
Is there a connection between weather conditions and the appearance of blooms?
Is it thought that the 'resting stage' is polyphyletic in the Hydrozoans? That is, did C. sowerbii evolve a separate resting stage from Hydra?
What is the size and shape of the resting stages? Do they exhibit any apparent adaptations such as burrs or hooks?
Is there any case known where a hydrozoan 'resting stage' has been revived from the intestinal contents of the animal?
What affect do freshwater jellyfish have on us and what affect do we have on them?
Our affect on jellyfish is unknown. We have discovered them in pristine waters as well as heavily polluted waters. In a study we did of over 20 chemical and physical parameters in about 6 dozen known jellyfish sites across PA, we found that the only factor significantly impacting their presence was the level of chlorine in the water.