None described.Invasion History: P. punctata was recorded only from Indo-Pacific waters prior to the 1950s. In 1955, an Atlantic basin population was discovered in Brazil (Haddad and Nogueira 2006). A large population there persisted briefly in coastal waters off the southern half of the country but disappeared within a few years. At the time, the organism was identified as Mastigias scintillae, another mastigiid jellyfish similar in appearance to Phyllorhiza (Moreira 1961, in Haddad and Nogueira 2006). Three decades later, around 1991, a second established population of P. punctata was reported from Brazil, this time off of the northeastern coastline (Silveira and Cornelius 2000). Ten years later (2001), evidence pointed to a new southern population of this non-indigenous jellyfish (Fuller 2005, Haddad and Nogueira 2006). This population may be the result of a natural range extension of the established northern population, or alternatively, accidental transport by the shipping industry, or perhaps an irruptive event within an extant cryptic population. Regardless of the mechanism, Haddad and Nogueira (2006) believe that P. punctata is now widespread in Brazil, occurring in both northern and southern waters. Since 2001, the established P. punctata population in Brazil undergoes a large summer bloom, and then declines and disappears the subsequent winter and spring (Haddad and Nogueira 2006).An established population of spotted jellyfish in a mangrove lagoon in Bonqueron Bay, Puerto Rico was reported by Cutress (1973). The first report of the animal in U.S. waters dates to California in 1981 (Carlton and Geller 1993). These Phillorhiza invasions pale in magnitude to one recorded in the northern Gulf of Mexico off Louisiana, Alabama and Mississippi in the summer of 2000. At that time, an estimated 10 million P. punctata medusae invaded the region and persisted at very high numbers between June and September before rapidly declining (graham et al. 2003). Interestingly, despite the magnitude of the population explosion, northern Gulf of Mexico P. punctata entirely lacked symbiotic zooxanthellae.In 2001, P. punctata was identified from collected specimens occurring in Florida in the central Indian River Lagoon near the city of Melbourne. Aerial and boat-based surveys undertaken at that time revealed only a handful of individuals. Even fewer individuals were detected the following year, and no irruptive events have been detected subsequent to this.Natural ocean circulation patterns may have been sufficient to transport P. punctata up into the northern Gulf of Mexico from established Caribbean Sea populations, as has occurred in other species (Graham 1998). Circulation set up by the Loop Current (part of teh Gulf Stream; a warm ocean current in the Gulf of Mexico that flows northward between Cuba and the Yucatan peninsula) and eddies spun off from it may have effected such transport (Johnson et al. 2004).The precise mechanisms of invasion in each of the above cases remain a matter of speculation. Invasions into new locales may occur via attachment of the sessile polyp stages to ship hulls or other submerged and towed structures. Larson and Arneson (1990) have proposed hull-fouling as the likely dispersal method transporting spotted jellyfish between the Pacific Ocean and the Caribbean Atlantic. Transport of free-swimming stages in ballast water has probably also led to some of the invasions (Carlton and Geller 1993). Passage of vessels through the Panama Canal probably facilitated introduction from the Pacific into the Atlantic basin (e.g., Graham et al. 2003, Bolton and Graham 2004).The fact that the first documented occurrence of the species in Brazil dates back to 1955 suggests that P. punctata was first transported between ocean basins at least 50 years ago (Silveira and Cornelius 2000)Putative transport routes and vectors may be critically examined through comparative molecular or morphological analyses among various populations. In fact, a recent comparative molecular study by Bolton and Graham (2004) concluded that the Brazillian population examined was not Phyllorhiza, but rather a member of genus Mastigias. Potential to Compete With Natives: Non-native jellyfish species like P. punctata have the capacity to compete with native species for food resources. To what extent such competition occurs is unknown, as are its ecological ramifications. P. punctata may also compete with other taxa for food resources (see below). Possible Economic Consequences of Invasion: Direct negative economic impact of the 2000 Gulf of Mexico P. punctata population explosion included several million dollars of fishery losses, primarily due to net damage. Some evidence also points to a greater than 25% reduction in the northern Gulf of Mexico white shrimp (Penaeus setiferus) harvest at that time, attributable to competition between the shrimp and jellyfish for food resources. (Graham et al. 2003). Predation on pelagic fish eggs and bivalve larvae was also pronounced (Graham et al. 2003).