Taxonomic name: Phyllorhiza punctata Von Lendenfeld, 1884
Synonyms: Cotylorhiza pacifica Mayer, 1915, Cotylorhizoides pacificus Light, 1921, Mastigias albipunctatus Stiasny, 1920, Mastigias andersoni Stiasny, 1926, Mastigias ocellatus Modeer, 1791, Mastigias scintillae Soares Moreira, 1961
Common names: Australian spotted jellyfish, spotted jellyfish, white-spotted jellyfish
Organism type: jellyfish
The jellyfish, Phyllorhiza punctata, has been introduced to North America from the Western Pacific Ocean and is threatening large commercial fisheries by feeding on the eggs and larvae of fish, crab and shrimp; clogging fishing nets; damaging boat intakes and fishing gear; and causing the closure of productive areas to fishing activities.
The umbrella or bell of Phyllorhiza punctata is nearly semi-spherical; about half as high as broad and punctuated by white crystalline inclusions, giving the appearance of spots. The eight radial canals communicate directly with the stomach and there are 8 thick transparent branching rhopalia (oral arms) which terminate with large brown bundles of stinging cells. 14 lappets are found in each octant of the umbrella. P. punctata average 45-50cm in bell diameter but there has been a maximum reported size of 62cm. Sub-genital ostia are wider than they are high, and the circular sub-umbrella muscles are interrupted by the 8 radial canals. (Hawaii Biological Survey, 2001; and Perry, 2005 in Graham et al. 2003).
There are several differences between Gulf of Mexico populations of P. punctata and others found globally. The two most obvious differences are pigmentation and size. Most populations of P. punctata are very deep brown, owing to the presence of zooxanthellae (algal symbionts). However, the Gulf of Mexico population does not host zooxanthellae. Populations in the Gulf of Mexico are also larger than those found elsewhere (A maximum size of 65cm rather than 35-40cm) (Graham et al. 2001).
coastland, estuarine habitats, marine habitats
Phyllorhiza punctata prefers warm temperate seas and is often abundantly aggregated in nearshore waters (Elkhorn Slough Foundation, undated). P. punctata is indigenous to the tropical western Pacific Ocean. It can often be found swimming near the surface in murky waters near estuaries in harbours and embayments. P. punctata has a wide distribution along Australian coastal and lagoon waters and range throughout the Indo-Pacific Ocean including the Philippine archipelago (Graham et al. 2003; Hawaii Biological Survey, 2001; and Perry, 2005).
Phyllorhiza punctata threatens large commercial fisheries of shrimp and crab in the Gulf of Mexico. It is feared this species will feed directly on the eggs and larvae of fish, crab and shrimp, having serious economic implications for commercial fishing. Similar invasive jellyfish have been known to cause major disruptions in marine fisheries in Europe and in some instances have driven out certain marine species. Whether or not P. punctata has this potential is yet to be determined (Martin, 2000). P. punctata's greatest economic impact thus far has been the clogging of shrimp nets. Estimated economic losses range in the millions of dollars. The indirect effect of predation on eggs and larvae of commercially important finfish and shellfish remains intangible (Graham et al. 2003). P. punctata also damages boat intakes and fishing gear, and have caused the closure of productive areas to fishing activities (Perry, 2005).
In their research, Graham et al. (2003) believe that P. punctata may have had an indirect effect on zooplankton production through changes in chemical or physical properties of the water. The manifestation of surface foam streaks down-wind of a super-swarm were likely due to high dissolved organic material (DOM) loading by the swarm. Mucus shed into the water when jellyfish are concentrated increases the viscosity of the water and may also elevate toxins as mucus-bound nematocysts are discharged (Graham et al. 2003).
Native range: Bolton and Graham (2004) state that Phyllorhiza punctata "was first described from Port Jackson, Australia (von Lendenfeld 1884). Kramp (1965, 1970) reported the species from Cairns, Queensland, Australia, and from Thailand: therefore, its native habitat
probably extends north from the south-central coast of eastern Australia, across northern Australia, and perhaps throughout SE Asia".
Known introduced range: Populations of P. punctata have been reported from Western Australia, Phillipines, Hawaii, the Atlantic Basin, Brazil, Puerto Rico, the eastern Meditteranean (Bolton and Graham, 2004; Graham et al. 2001). Populations from the Caribbean and the Gulf of Mexico are geograpically closer to each other than those populations on the west coast of the United States and Australia. Analyses show that populations from the Caribbean and the Gulf of Mexico are the least similar to each other and it is most likely that P. punctata in the Gulf of Mexico orginate from either Australia or the West Coast (Bolton and Graham, 2004).
Introduction pathways to new locations
Other: The coastal invasion was initially reported with biologists theorising that the jellyfish broke off the Loop Current that circulates through the Gulf and ended up in an eddy south of the Alabama and Florida panhandle. The Naval Research Laboratory at the Stennis Space Center confirmed this through satellite imagery (Martin, 2000).
Among invasive marine species, P. punctata has a relatively well-documented history of invading tropical and subtropical environments. Despite this, there is no direct evidence of translocation routes or the mechanisms by which translocation has occurred. The invasion of the Northern Gulf of Mexico has been theorised to represent an inevitable distributional shift of an invasive hub population in the Caribbean Sea facilitated by periodic oceanographic connections between the regions, or by the transportation of benthic scyphistomae on the hulls of ships (Bolton and Graham, 2004).
Ship ballast water: P. punctata are thought to be introduced as ship-fouling scyphistomae or as ephyrae in ballast water (Hawaii Biological Survey, 2001).
Ship/boat hull fouling: Bioinvasions of scyphozoans usually occur in the sessile polyp stage with ships or other seagoing infrastructure (e.g. towed oil or gas platforms) as vectors. Spread of P. punctata throughout the Pacific Ocean and between the Pacific Ocean and Caribbean Sea has been attributed to hull-fouling transport of polyps (Larson and Arneson 1990; Perry, 2005).
Local dispersal methods
Water currents: Transport of P. punctata from the Caribbean Sea to the northern Gulf of Mexico may be the result of natural ocean circulation processes. Similar transport of other Caribbean medusae has occurred via this method. Origin of the medusae that invaded northern Gulf of Mexico waters in the summer of 2000 was attributed to circulation processes associated with the Loop Current and its spin-off eddies by Johnson et al. (2004) (Perry, 2005).
During the creation of this profile of Phyllorhiza punctata, no information about prevention, eradication, control, containment or mitigation was found
Fluid enters the sub-umbrella space of Phyllorhiza punctata during the relaxation phase and flows over clusters of mouthlets near the base of the oral arm disk and in the centre of the fused oral arm cylinder. The pulsing contraction and relaxation phases of the bell transports prey to different capture surfaces within. Prey is ingested by small polyp-like mouthlets. Swimming activity, and the creation of fluid flows used for prey capture, is continuous, as is feeding, and is central to P. punctata's foraging behaviour (Ambra et al. 2001).
Basic cnidarian reproduction involves an asexually reproducing polyp stage, alternating with a sexually reproducing medusoid stage. This reproductive strategy is known as "alternation of generations". The scyphozoan reproductive cycle is typically dominated by the medusoid stage. The adult planktonic medusa is commonly referred to as a jellyfish. The planktonic planula larvae of the sexually reproducing medusa typically settles to the bottom where it attaches and grows (scyphistoma stage). It may then either directly form additional scyphistoma via a process of budding, and/or develop into a strobila, a benthic form which asexually produces and releases young medusa known as ephyrae. This alternation of generations may facilitate the transport of P. punctata by shipping through ballast water (planktonic planula, ephyrae or medusa) or fouling (benthic scyphistoma or strobila) (Hawaii Biological Survey, 2001).
Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Wednesday, 24 May 2006