Department of Fish and Wildlife Says Freshwater Jellyfish Exist in Kentucky

Not all jellyfishes can be found in the sea because, according to the Department of Fish & Wildlife (KDFW), there are freshwater jellyfishes in Kentucky.

Are they dangerous?

Fortunately, their stings cannot harm humans, because their tentacles' cells are not able to puncture our skin, and so they are not as painful as the notorious marine or sea jellyfishes. One should, therefore, have no worries about being hurt by these creatures.

The Department of Fish & Wildlife said that these jellyfishes could be observed starting in the late summer up to the early autumn in various calm freshwater bodies such as rivers, ponds, and lakes.

READ: Pheromone Chemical Triggers Locust Swarms and Can Be Used to Prevent Plagues

Sightings of Jellyfishes Surprised Many

The department's post garnered hundreds of comments who also recounted their encounters with the animal in the states of Indiana and Kentucky. From the public's comments, the animals can be seen in the areas of Utica, Erlanger, and Owensboro.

Many of the reports also mentioned that their loved ones did not believe them when they said that they saw the animals, perhaps because people usually associate jellyfishes only with the sea.

One of those who saw the jellyfishes said that they were present in Indiana's Deam Lake, but everyone they knew was skeptical about it. Another commenter stated that they thought they were going insane when they had the sighting.

The Natural History of Freshwater Jellyfish

The USGS or US Geological Survey says that these freshwater jellyfish have tentacles numbering 50 up to 500. They were first seen in the state of Kentucky in the year 1916. Currently, they have been recorded as present in Washington, DC, and 44 other states.

Its scientific name is Craspedacusta sowerbyi, and they were first described in 1880 from specimens in tanks of water lilies in London's Regents Park. They were brought there together with plants imported from Southeast Asia.

The animal is what is known as a hydrozoan; it can be recognized once it takes on the form of the usually-known bell-shaped configuration, a stage in its life when it is called a hydromedusa.

It can reproduce sexually or asexually. The mature hydromedusa engages in sexual activity through the release of sperm and eggs into the water. Fertilization occurs, then cleavage, after which its embryo grows and elongates to form the larva or planula. This goes to the substrate, settles there, and soon becomes a polyp.

Polyps can propagate by budding. These can form colonies, metamorphose to new polyps, and finally make buds that ultimately become a medusa. In its hydromedusa form, the jellyfish can reach a maximum of 25 millimeters or roughly one inch in diameter.

Diet

Craspedacusta sowerbyi feeds on various small organisms which approaches it. It opportunistically preys on these creatures as they come within reach. It uses cnidocytes to catch its food.

Movement

The freshwater jellyfish swims in an up & down motion, with expansion and contraction of its bell structure and its velum. The latter is a circular, thin membrane on its underside which separates it from true, scyphozoan jellyfishes.

Habitat

Craspedacusta sowerbyi jellyfishes can be usually found in ponds, flooded quarries, river backwaters, and various calm waters. They have already colonized and are already quite common in most areas all over the world that have temperate climates.