Invasion History

First Non-native North American Tidal Record: 2009
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 2009

General Invasion History:

Rhizostome jellyfish of the genus Mastigias are widespread in the Indo-Pacific. They are most abundant and notable in marine lakes on islands, with underground connections to ocean waters. Mastigias sp. 1 was identified from 'Halimeda Lagoon', in the interior of Kakaban Island, off Borneo, Indonesia (2°N, 118°E), where the jellyfish are a tourist attraction for divers. The marine lake is connected to the Celebes Sea through fissures in the bedrock (Tomascik and Mah 1994). The taxonomy of the genus is confused, owing to its similarity with the genus Phyllorhiza, especially the widespread invader P. punctata. A molecular comparison of 12 Mastigias populations found that Mastigias sp. 1 was most similar to introduced populations on No Name Key, Florida, and Laguna Joyuda, Puerto Rico (Bayha and Graham 2011). Possible vectors include medusae in ballast water or polyps in fouling on ships or oil platforms. However, medusae or planaulae would have to enter the quarry through cracks in the coral rocks of the key. Another possibility is discarded 'live rock’, pieces of coral with live organisms, used as decorations in marine aquariums. Living polyps of the medusa Cassopeia sp. have been found on pieces of live rock imported from the Indo-Pacific (Bolton and Graham 2006).

North American Invasion History:

Invasion History on the Gulf Coast:

In October 2009, Bayha and Graham (2011) sampled a jellyfish population in a flooded quarry on No Name Key, Florida, in the Gulf of Mexico. According to the quarry operators, the jellyfish had been present for over 20 years. Morphologically, these jellyfish had the characteristics of the genus Mastigias and were most similar to Mastigias sp. 1 from Indonesia.

Invasion History Elsewhere in the World:

Introduced rhizostomid jellyfish have been present in Laguna Joyuda, Puerto Rico since the 1970s (Cutress 1971, cited by Larson and Arneson 1990), but their identity has been uncertain. All of them were initially identified as Phyllorhiza punctata, but many specimens resembled Mastigias (Bolton and Graham 2004). Recent molecular sampling indicates that both Phyllorhiza punctata and Mastigias sp. 1 have been present in Laguna Joyuda, but the co-occurrence of the two species is uncertain (Bayha and Graham 2011).


Mastigias sp. 1 is a rhizostome scyphozoan, with a large, conspicuous medusa. Molecular analysis indicated that Florida and Puerto Rican specimens were identical to a population from Indonesia, but none of these corresponded to a named species. Mastigias spp. have a tall, hemispherical bell, eight oral arms with mouths at the extremities, and lack marginal tentacles. Minute tentacles are present around the lips of the mouths. In the genus Mastigias, the oral arms have three edges or wings along their length, and end in club-shaped projections. The upper surfaces of the arms are covered with masses of filaments with stinging cells. Numerous mouths are located on the lower surfaces of the arms. There are eight rhopalia (sense organs containing an eye and statocyst) on the margin of the bell, with canals connected to the marginal canal, and running inward to the stomach (Mayer 1910; Bayha and Graham 2011). Between each pair of rhopalia, the rim of the umbrella is divided into small rectangular projections, called lappets. Among species in the genus, the number of lappets ranges from 5 X 8 to 16 X 8- the number isn't clear from Bayha and Graham's photograph, but appears to be about 6 X 8 (Bayha and Graham 2011).

Mastigias sp. 1, based on photographs by Bayha and Graham (2011), is olive-brown, with circular white spots on the bell, and masses of whitish filaments on the upper parts of the oral arms. Bell diameters of two photographed specimens were 4 and 6 cm (Bayha and Graham 2011). Mastigias, presumably this species, from Jellyfish Lake, Kakaban, Indonesia, are 10-20 cm wide ( Mastigias sp. 1 is known so far from Kakaban, Indonesia, a quarry on No-Name Key, Florida, and Laguna Joyuda, Puerto Rico. Molecular comparisons (DNA, COI) were made using M. papuensis from Palau, Mastigias sp. 2 from Papua New Guinea, and Mastigias sp. 1 from Indonesia (Bayha and Graham 2011).

Polyps of Mastigias sp. 1 have not been described. Those of the related Phyllorhiza punctata are ~2 mm in diameter, with tentacles up 10 mm long (Rippingale and Kelly 1995). It's likely that such polyps would be easily overlooked. A key, describing and showing ephyrae of Mastigias papuaei is in Straelher-Pohl and Jarms (2010).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Cnidaria
Class:   Scyphozoa
Order:   Rhizostomeae
Suborder:   Kolpophorae
Family:   Mastigiidae
Genus:   Mastigias
Species:   sp. 1


Potentially Misidentified Species

Mastigias papuae
Native to Indonesia

Phyllorhiza punctata
Introduced to Gulf, East Coast (FL-SC), and San Diego Bay

Rhopilema verrilli
Native, Caribbean to NC, occasionally to MA

Stomolophus meleagris
Native, Caribbean to NC



Scyphozoan jellyfish have a life-cycle including a conspicuous medusa and a small polyp (scyphistoma) stage. The planktonic medusae have two sexes. Fertilized eggs develop into planula larvae, which appear to be brooded on the surface of the medusa. In the related Phyllorhiza punctata, shaking jars of water with the medusae resulted in the release of planulae, which settled to grow into small (~2mm in diameter) polyps. The polyps feed on zooplankton and grow, and bud off single, disc-shaped ephyrae, which grow into medusae (Rippingale and Kelly 1995).

Many and maybe all Mastigias medusae contain zooxanthellae, symbiotic algae, which provide much of their nutrition through photosynthesis. In lagoons and marine lakes, these jellyfish show patterns of vertical and horizontal migration, sinking to acquire nutrients at night, and moving horizontally to stay in sunlight by day (Dawson et al. 2001; Dawson and Hamner 2003). Zooxanthellae are not mentioned in Bayha and Graham's (2011) article, but the color of medusae in their photographs match those with zooxanthellae. However, the medusae apparently do feed on zooplankton, and young M. papuensis (Mastigias spp.) are especially abundant in anchialine ('marine') lakes, with underground connections to the ocean (Dawson et al. 2001; Dawson and Hamner 2003; Bayha and Graham 2011).



Trophic Status:

Primary Producer



General HabitatUnstructured BottomNone
General HabitatMangrovesNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone
Vertical HabitatPlanktonicNone

Tolerances and Life History Parameters

Broad Temperature RangeNoneSubtropical-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Impacts have not been reported for the introduced populations in Florida and Puerto Rico. However, the Mastigias populations in the 'jellyfish lakes' in Palau, Kakaban, and other islands have become tourist attractions, drawing divers and people riding in glass-bottomed boats to see the swarms of stingless jellyfish migrating into sunlit waters (Dawson et al. 2001; Dawson and Hamner 2003).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 2009 Def Estab
S206 _CDA_S206 (Vero Beach) 2009 Def Estab
CAR-IV None 2009 Def Unk
EAS-III None 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Barnes, Robert D. (1983) Invertebrate Zoology, Saunders, Philadelphia. Pp. 883

Bayha, Keith M.; Graham, William M. (2011) First confirmed reports of the rhizostome jellyfish Mastigias (Cnidaria: Rhizostomeae) in the Atlantic basin, Aquatic Invasions 6(3): 461-466

Bolton, Toby F.; Graham, William M. (2006) Jellyfish on the rocks: bioinvasion threat of the international trade in aquarium live rock., Biological Invasions 8: 651-653

Bolton, Toby F.; Graham, William M. (2004) Morphological variation among populations of an invasive jellyfish., Marine Ecology Progress Series 278: 125-139

Dawson, Michael N.; Hamner, William M. (2003) Geographic variation and behavioral evolution in marine plankton: the case of Mastigias (Scyphozoa, Rhizostomeae), Marine Biology 143: 1161-1174

Dawson, Mike N.; Martin, Laura E.; Penland, Lolita K. (2001) Jellyfish swarms, tourists, and the Christ-child, Hydrobiologia 451: 131-144

Johnson, William S.; Allen, Dennis M. (2005) <missing title>, Johns Hopkins Press, Baltimore. Pp. <missing location>

Larson, Max R.; Foreman, Michael G. G.; Levings, Colin D.; Tarbotton, Michael R. (2003) Dispersion of discharged ship ballast water in Vancouver Harbour, Juan de Fuca Strait, and offshore of the Washington Coast, Journal of Environmental Engineering and Science 2(3): 163-176

Mayer, A. G. (1910) Medusae of the World., In: (Eds.) . , Washington, D.C.. Pp. 231, 276-278

Rippingale, R.J.; Kelly, S.J. (1995) Reproduction and survival of Phyllorhiza punctata (Cnidaria: Rhizostomeae) in a seasonally fluctuating salinity regime in Western Australia., Marine and Freshwater Research 46: 1145-1151

Straehler-Pohl, L.; Jarms, G. (2010) An identification key for young ephyrae: a first step for early detection of jellyfish blooms, Hydrobiologia 645: 3-21

Tomascik, Tomas; Mah, Annamarie J. (1994) The ecology of Halimeda lagoon: An anchiahaline lagoon of a raise atoll, Kakaban Island, East Kalimantan, Indonesia, Tropical Biodiversity 2(3): 385-398