This week’s image is of an Australian Spotted Jelly (Phyllorhiza punctata ), seen at the Houston Zoo:
This jelly is native to the southwestern Pacific Ocean, but was accidentally introduced into the waters of the Gulf of Mexico and the Western Atlantic Ocean around 1950. They’ve done so well in their adopted new home that the largest one ever recorded was found on a beach in North Carolina in 2007.
Fortunately for swimmers, the spotted jelly has only a mild venom and isn’t seen as a threat to humans in the water. But the spotted jelly’s explosive population growth in the Caribbean and Gulf of Mexico poses a huge threat to local fisheries. Each jelly filters more than 10,000 gallons of water each day — ingesting plankton in competition with native species, as well as the eggs of many native fish species. It’s felt that this species of jellyfish, likely introduced to the region via ship hull fouling or in in ballast water, has caused millions of dollars of losses to fisheries over the years.