Photographer: Trish Murphey Affiliation: NC Department of Environment ad Natural Resources Source:www.bugwood.org Copyright: CC BY-NC 3.0
Phyllorhiza punctata is a large jellyfish with a rounded and somewhat flattened gelatinous bell that is clear or tinted brown with many small reflective areas that look like white spots. This spotted jellyfish averages about 18-20 inches in bell diameter however, researchers have found one with a 28 inch bell diameter off of the coast of North Carolina.
Though the original description published by von Lendenfeld in 1884 originally described Port Jackson, Australia as the ‘type’ locality, it actually occurs throughout the Indo-Pacific Ocean including the Philippine archipelago, Thailand and Japan.
In the Gulf, this invader has formed huge swarms in recent years. Each jellyfish can clear 50 cubic meters of water filled with plankton in one day, making dense aggregations of Australian spotted jellyfish dangerous because they can alter food webs in the water column. Gulf fisheries have been affected by P. punctata for the following reasons: they eat larval fish, compete with suspension feeding fish & shrimp for food, and they clog the fishing nets.
The polyp stage of this species, which buds off to develop juvenile jellyfish, could be transported to our region on ship hulls. With this jellyfish being found in California waters over to the Gulf of Mexico and Atlantic waters it is a threat to Texas' coastal ecosystems.
This is a true jellyfish that goes through the juvenile polyp stage and the adult medusa stage. Jellyfish can live for up to five years in the polyp stage and up to two years in the medusa stage. Like most jellyfish they feed on zooplankton, which is an important animal for all aquatic ecosystems. When found in warm waters these jellyfish flourish, they are mostly salt tolerant but low salinities may have a negative effect on the species. In times of low salinity these jellyfish exhibit loss of their zooxanthellae, which are symbiotic algae. Zooxanthellae use nutrients not vital to the jellyfish to create energy for the jellyfish via photosynthesis. Not all jellyfish have symbiotic algae and whenever the zooxanthellae are lost in low salinity waters it lowers the jellyfish’s ability to survive in nutrient poor waters.
They have only a mild sting and their venom isn’t toxic or a threat to humans. However, their ability to consume massive amounts of zooplankton makes them a threat to water column ecosystems all over the world.
The species has been found in the waters off the Hawaiian Islands since at least 1945 and in large numbers in the Gulf of Mexico since 2000. It has been hypothesized that budding polyps may have attached themselves to ships, or were carried in a ship's ballast tank which was subsequently dumped. As an invasive species, it has become a threat to several species of shrimp. In Gulf waters, the medusa grow to unusually large sizes, upwards of 24 inches across.
In July 2007 small individuals were seen in Bogue Sound much further north along the North Carolina coast and all the way south to Florida. It has also been spotted off the Southern California coast, but its presence there has not yet been confirmed.
West Pacific from Australia to Japan
U.S. Present: West Coast, Gulf of Mexico and Atlantic Coast near North Carolina
U.S. Habitat: Warm seas and tend to aggregate in near-shore waters. Phyllorhiza punctata has become an issue in the Northern Gulf of Mexico near the Mississippi Sound affecting zooplankton levels. It is highly possible that this jellyfish has started to occupy the region of the Gulf bordering Texas.
In the Pacific region, there are snails that eat the budding polyp stage of the jellyfish but in the North American waters these snails are not present to keep the jellyfish populations lower. Besides knowing that low salinity causes P. punctata to lose their symbiotic algae, there isn’t much known on how to manage these jellyfish populations; especially since they are found in wide open ocean areas. Capturing live jellyfish can help lower the population, but there could be millions of them in one area and fishermen can only devote so much time to an animal that generates no revenue for them. Vigilant eyes on ocean waters and continual reports of Australian spotted jellyfish sightings can help estimate how many there are within the Gulf of Mexico and further measures can be taken to erdaicate is invasive animal.
Graham W.M., Martin D.L., Felder D.L., Asper V.L., and H.M. Perry. 2003. Ecological and economic implications of a tropical jellyfish invader in the Gulf of Mexico. Biological Invasions 5:53-69.
Heeger T, Piatkowski U and Moeller H. 1992. Predation on jellyfish by the cephalopod Argonauta argo. Marine Ecology Progress Series 88:293–296
Larson R.J. and A.C. Arneson. 1990. Two medusae new to the coast of California: Carybdea marsupialis (Linnaeus, 1758), a cubomedusa and Phyllorhiza punctata von Ledenfeld, 1884, a rhizostome scyphomedusa. Bulletin of the Southern California Academy of Sciences 89:130-136.
Mianzan HW and Cornelius PFS .1999. Cubomedusae and Scyphomedusae. In: BoltovskoyD(ed) South Atlantic Zooplankton, pp 513–559. Backhuys Publishers, Leiden,The Netherlands
Verity, Peter G., J. E. Purcell, and M. E. Frischer. 2011. Seasonal patterns in size and abundance of Phyllorhiza punctata: an invasive scyphomedusa in coastal Georgia (USA). Marine biology 158(10):2219-2226.
Woodward, Susan L., and Joyce Ann. Quinn. 2011. Australian Spotted Jellyfish. Encyclopedia of Invasive Species: From Africanized Honey Bees to Zebra Mussels. Santa Barbara, CA: Greenwood. 45-47. Print.
Internet Sources
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