Invasion History

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

General Invasion History:


North American Invasion History:




Taxonomic Tree

Kingdom:   Animalia
Phylum:   Cnidaria
Class:   Hydrozoa
Subclass:   Hydroidolina
Order:   Leptothecata
Family:   Campanulariidae
Genus:   Clytia
Species:   paulensis


Campanularia paulensis (Vanhoffen, 1910)
Clytia ulvae (Stechow, 1919)
Obelia paulensis (Stechow, 1919)

Potentially Misidentified Species

Clytia cylindrica

Clytia edwardsi

Clytia hemispherica

Clytia kincaidi



General HabitatCoarse Woody DebrisNone
General HabitatUnstructured BottomNone
General HabitatOyster ReefNone
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone
Vertical HabitatPlanktonicNone

Tolerances and Life History Parameters

Minimum Salinity (‰)17None
Maximum Salinity (‰)40None
Broad Temperature RangeNoneWarm temperate-Tropical
Broad Salinity RangeNoneMesohaline-Euhaline (Calder 1976, field observationms

General Impacts

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NA-ET3 Cape Cod to Cape Hatteras 1968 Crypto Estab
CAR-VII Cape Hatteras to Mid-East Florida 1972 Crypto Estab
NEA-III None 1889 Crypto Estab
NEA-II None 1977 Crypto Estab
NEA-IV None 1935 Crypto Estab
MED-II None 1919 Crypto Estab
MED-III None 0 Crypto Estab
ANT-AU2 None 1903 Crypto Estab
RS-2 None 1964 Crypto Estab
WA-V None 1919 Crypto Estab
SA-III None 1993 Crypto Estab
AUS-III None 1924 Crypto Estab
AUS-VIII None 1985 Def Estab
MED-VI None 0 Crypto Estab
M130 Chesapeake Bay 0 Crypto Estab
MED-I None 0 Crypto Estab
NEA-V None 0 Crypto Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Calder, Dale R. (1971) Hydroids and hydromedusae of southern Chesapeake Bay., Virginia Institute of Marine Science, Special Papers in Marine Science 1: 1-125

Calder, Dale R. (1972) Phylum Cnidaria, Special Scientific Report, Virginia Institute of Marine Science 65: 97-102

Calder, Dale R. (1976) The zonation of hydroids along salinity gradients in South Carolina estuaries, In: (Eds.) Coelenterate Ecology and Behavior. , New York. Pp. 165-174

Calder, Dale R. (1997) Introduced hydroids in Chesapeake Bay, email, Zoologische Verhandlingen Leiden <missing volume>: <missing location>

Calder, Dale R.; Hester, Betty S. (1978) Phylum Cnidaria., In: Zingmark, Richard G.(Eds.) An Annotated Checklist of the Biota of the Coastal Zone of South Carolina. , Columbia. Pp. 87-93

Cornelius, P. F. S, (1982) Hydroids and medusae of the family Campanulariidae recorded from the eastern North Atlantic, with a world synopsis of genera., Bulletin of the British Museum, Natural History (Zoology) 42(2): 37-148

Haydar, Deniz (2012) What is natural? The scale of cryptogenesis in the North Atlantic Ocean, Diversity and Distributions 18: 101-110

Megina, Cesar; Gonzalez-Duarte, Manuel M.; Lopez-Gonzalez, Pablo J. Piraino, Stefano (2013) Harbours as marine habitats: hydroid assemblages on sea-walls compared with natural habitats, Marine Biology 160(2): 371-381

Mergner, H., Wedler, E. (1977) Uber die hydropolypenfauna des Roten Meeres und seiner Ausgange., 'Meteor' Forschungen-Ergebnisse 24(Reihe D.): 1-32

Millard, N. A. H. (1975) Monograph on the Hydroida of southern Africa, Annals of the South African Museum 68: 1-513

Watson, Jeanette E. (1995) New records and redescriptions of thecate hydroids from southern Australia, Proceedings of the Royal Society of Victoria 106: 147-162