Practical information to identify and manage non-native, invasive plants and animalsThe Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
Australian spotted jellyfish|
Human HealthThe Australian spotted jellyfish has a mild sting which can be treated with vinegar.
Prohibited ListsAs of 2010, this species is not prohibited by the TPWD.
Introduction PathwaysP. punctata was transported to the Caribbean from the Pacific Ocean over 45 years ago (Graham et al. 2003) via ship hull fouling by attached sessile polyps. Transport into the Gulf of Mexico from the Caribbean in 2000 likely occurred via an intrusion of the Loop Current onto the Mississippi Shelf through eddy-shedding processes (Johnson et al. 2005). Ship hull fouling and ship ballast water are other possible introduction pathways for these jellyfish into the Gulf of Mexico (Perry 2006b).
Geographic DistributionThis species was first reported in the U.S. off the coast of California in 1981. A cryptic population may have existed in the northern Gulf of Mexico since 1993 (Graham et al. 2003). In the spring and summer of 2000, millions were found in coastal regions of Mississippi and Louisiana in the northern Gulf of Mexico (Graham et al. 2003; Johnson et al. 2005). One juvenile was collected in West Galveston Bay in June 2006.
Specific Primary HabitatsThe Australian spotted jellyfish prefers the warm, temperate waters in estuaries and the open sea. This jellyfish has been shown to undergo large population increases. This species is not extremely tolerant of low salinity conditions, however, and can experience population declines in coastal areas during periods of heavy stormwater runoff (Masterson 2007b).
Ecological, Economic, or Social ImpactThe Australian spotted jellyfish is believed to feed on the planktonic eggs and larvae of fish, crab, and shrimp, and thus, may alter food webs and commercial fisheries in the Gulf of Mexico. High densities of these jellyfish can clog shrimp nets and boat intakes as well, and in the past have caused the temporary closure of fishing areas (Perry 2006b). This species may also have an effect on zooplankton by changing the physicochemical properties of waters in which the jellyfish were highly concentrated (ISSG 2006g).
Physical DescriptionPhyllorhiza punctata is characterized by a round and flattened bell which appears clear (Gulf of Mexico) or light brown (other worldwide populations) in color. Gulf of Mexico species are clear because they lack symbiotic zooxanthellae (Graham et al. 2003) present in other populations. The bell contains many crystalline refractive spots, just beneath the surface. The average bell diameter ranges from 45-50 cm and up to 62 cm in the Gulf of Mexico. This jellyfish has eight oral arms which protrude from the central mouth area with bundles of brown nematocysts (stinging cells) attached to the ends (Graham and Bolton 2004).
Reproduction CharacteristicsThe life cycle of this species can be divided into two stages. The medusoid, or "jellyfish" stage, is the free-living, dominant life stage of P. punctata which reproduces sexually, via external fertilization. The other stage is the polyp, or stationary life stage, which reproduces asexually via budding and lives attached to hard surfaces. Polyp stages produce new free-living medusa. Alternation between sexual and asexual stages is believed to aid in the dispersal of this species (ISSG 2006g; Masterson 2007b).
FeedingP. punctata continuously forages for zooplankton, including eggs and larvae of some commercially important species.
ControlEarly detection is key to preventing the spread and establishment of this species and regional/local monitoring or surveillance is essential. Nonnative jellyfish should not be released in local waterways. If found in local waters, note the location and notify the TPWD.
This species belongs to the following lists:
ImagesTo view a larger version of an image, click on the thumbnail.
Page Updated/Reviewed: 09/07/2010 10:20 AM |