Invasion History

First Non-native North American Tidal Record: 1991
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1991

General Invasion History:

Eualetes tulipa was described from Panama in 1843, and is considered probably native to the tropical Eastern Pacific. Most Panama collections are from the Panama Bay region (Hughes 1985; U.S. National Museum of Natural History 2019), but records are also known from the Veraguas Province (Gonzalez 2002), and  offshore on Cocos Island, Costa Rica (Cortes 2012). Since E. tulipa has been found in several widely separated locations around the world (Florida, Venezuela, Brazil, Hawaii, India), there is some uncertainty about its native region. Eualetes tulipa has brooded larvae, so anthropogenic dispersal is largely by hull-fouling of ships (Spotorno-Oliveira et al. 2018).

North American Invasion History:

Invasion History on the East Coast:

Eualetes tulipa was noticed by Michael Hadfield on Rickenbacker Causeway, Miami, Florida, some time before 1991 (Carlton and Eldredge 2009; James T. Carlton, personal communication 2/11/2019). The first published collection of Eualetes tulipa in U.S. waters was on Peanut Island, Palm Beach County, Florida, in Lake Worth in 1997. Additional collections were made in 2010 in the Indian River Lagoon at Port Canaveral and Fort Pierce Inlet (Golding et al. 2014; Florida Museum of Natural History 2019). It is likely that this worm-shell has been introduced at other locations in Florida, or elsewhere in the southeastern US.

Invasion History in Hawaii:

Eualetes tulipa was described from Coconut Island, Kaneohe Bay, Oahu in 1972, under the name Vermetus alii (Hadfield et al. 1972). It occurs intertidally on sea walls and coral heads, and is often found in marinas, in Pearl Harbor, Honolulu Harbor, and harbors and marinas in Kauai, Molokai, Maui, and Hawaii (Coles et al. 1999b; Coles et al. 2001; Carlton and Eldredge 2004).

Invasion History Elsewhere in the World:

Eualetes tulipa was described from Panama, and is presumed to be native there. Its first record in the Atlantic Ocean was in a powerplant in Carabobo State, Venezuela in 1986 (Miloslavich et al. 2010). In 2005, E. tulipa was found on fouling plates in one port of Fortaleza, Ceara State, northeast Brazil, and at another port in the same city in 2009. In 2015, it was found at a port further south in northeastern Brazil, in Natal, Rio Grande (Barroso et al. 2018; Spotorno-Oliveira et al. 2018). 

In 2014, Eualetes tulipa was found on breakwaters in Royapuram fishing harbour, in Chennai, Tamil Nadu State, India, on the Strait of Mannar (Jebakumar et al. 2015). It has also been found in Singapore, by DNA barcoding of museum vermetid specimens, with 16 records from 1992 to 2016 (Tan et al. 2021).


Eualetes tulipa is a vermetid (worm-shell), a sessile gastropod, whose shell are long, coiling tubes attached to hard surfaces. The protoconch (initial larval shell) is at right angles to the following whorls (Abbott 1974). The protoconch is inflated and globose, with 1.5 whorls, buried by the whorls of the protoconch. The coils are flattened where they are attached to the substrate. The shell grows in 6–10 loose or tight spiral coils, piled up, with the feeding-tube and its circular aperture often rising several centimeters above the substrate. The feeding-tube is ringed with growth scars. Eualetes tulipa has a disc-shaped operculum, formed of spiral lamellae. The length of the shell ranges from 15 to 70 mm, with reported means of 33–38 mm (Brazil, Spotorno-Oliveira et al. 2018; Hawaii, Hadfield et al. 1972), but wider (60–70 mm) in Panama and Venezuela (Keen 1971, cited by Spotorno-Oliveira et al. 2018; Miloslavich et al. 2010). The feeding-tube is 7–30 mm long (Hadfield et al. 1972; Spotorno-Oliveira et al. 2018). The colors of the shell vary from white to gray to reddish-brown (Keen 1971, cited by Spotorno-Oliveira et al. 2018 (Panama); Hadfield et al. 1972 (Hawaii); Miloslavich et al. 2010 (Venezuela); Jebakumar et al. 2015 (India); Spotorno-Oliveira et al. 2018 (Brazil)).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Gastropoda
Order:   Neotaenioglossa
Family:   Vermetidae
Genus:   Eualetes
Species:   tulipa


Vermetus tulipa (Rousseau in Chenu, 1843)
Serpulorbis angulatus (Chenu, 1844)
Serpulorbis panamensis (Chenu, 1844)
Thylacodes angulatus (Rousseau in Chenu, 1844)
Thylacodes effusus (Valenciennes in Chenu, 1844)
Vermetus alii (Hadfield & Kay in Hadfield et al, 1972)
Vermetus angulatus ( Rousseau in Chenu, 1844)
Trypsycha tulipa (None, None)
Vermetus sp. (Miloslavich and Penchaszadeh, 1992)

Potentially Misidentified Species

'Hadfield's vermetid'
Unidentified vermetid resembling the Mediterranean Thylacodus rugulosus found in Kewalo Basin, Oahu (Strathmann and Strathmann 2006).

Petaloconchus varians
Native, North Carolina to Brazil (Abbott 1974)

Thylacodes decussatus
Native, Mexico-Venezuela (Rosenberg 2019)

Thylacodes vandyensis
Described from shipwrecks off Florida, unknown origin (Bieler et al. 2017)



Eualetes tulipa has been found on tropical and subtropical shores. They have colonized shores in the Cabo Frio area, where temperatures can drop to 12 °C during upwelling, but also on the shores of northeast Brazil, where temperatures reach 28 °C (Spotorno-Olivieira et al. 2018). This worm-shell settles on rocky substrates, coral heads, and artificial substrates, including metal and concrete walls, breakwaters, and buoys (Miloslavach et al. 2010; Jebakumar et al. 2018; Spotorno et al. 2018). Eualetes tulipa does not settle on wood, but can settle on bivalves attached to wood, so dispersal on rafted wood is possible (Spotorno-Olivieira et al. 2018). It primarily feeds by spreading mucus threads in the water, and reeling them in to trap suspended particles, but also feeds by direct ciliary feeding, retaining particles attached to the cilia (Hadfield et al. 1972; Hughes 1985; Miloslavach and Penchaszadeh 1992). In Venezuela, this gastropod can become very abundant in areas with heavy sewage and sediment discharges and phytoplankton blooms (Miloslavach et al. 2010).


Phytoplankton, Detritus

Trophic Status:

Suspension Feeder



General HabitatMarinas & DocksNone
General HabitatRockyNone
General HabitatVessel HullNone

Life History

Eualetes tulipa is a vermetid (worm-shell), a sessile, suspension-feeding gastropod, living in an elongated, coiled, attached shell. Sexes are separate and eggs are brooded. Lecithotrophic larvae are briefly planktonic. Spawning occurs year-round in Venezuela. Females brood up to 54 egg capsules containing up to 290 eggs, which develop into briefly swimming veligers. Larvae settle in less than 24 hours (Miloslavach et al. 2010).

Tolerances and Life History Parameters

Minimum Temperature (ºC)12During upwelling, Cabo Frio region, Brazil (Spotorno et al. 2018)
Maximum Temperature (ºC)28northeast Brazil (Spotorno et al. 2018)
Minimum Length (mm)50Body length of animal extracted from tube (Miloslavich et al. 2010)
Maximum Length (mm)140Body length of animal extracted from tube (Miloslavich et al. 2010)
Broad Temperature RangeNoneSubtropical-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

The worm-shell Eualetes tulipa appears to be capable of rapid dispersal in ship fouling, and is a potential competitor with other fouling organisms, especially in polluted areas (Miloslavich et al. 2010; Spotorno-Olivieira et al. 2018).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 1991 Def Estab
S190 Indian River 2010 Def Estab
S186 _CDA_S186 (Cape Canaveral) 1997 Def Estab
SEP-H None 0 Native Estab
SP-XXI None 1972 Def Estab
CAR-III None 1986 Def Estab
SA-IV None 2005 Def Estab
SA-III None 2015 Def Estab
SA-II None 2009 Def Estab
CIO-II None 2014 Def Estab
S200 Biscayne Bay 1991 Def Estab
EAS-VI None 1992 Def Estab
CMAR1 Isla del Coco / Cocos Island 0 Native Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Abbott, R. Tucker (1974) American Seashells, Van Nostrand Reinhold, New York. Pp. <missing location>

Barroso, Cristiane Xerez; Rabay, Soraya Guimarães; Matthews-Cascon, Helena (2018) Mollusks on recruitment panels placed in an offshore harbor in tropical northeastern Brazil , Arquivos de ciencias do mar 51(1): 65-74

Carlton, James T.; Eldredge, Lucius (2009) Marine bioinvasions of Hawaii: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago., Bishop Museum Bulletin in Cultural and Environmental Studies 4: 1-202

Carlton, James T.; Eldredge, Lucius G. (2015) Update and revisions of the marine bioinvasions of Hawai‘i: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago, Bishop Museum Bulletin in Cultural and Environmental Studies 9: 25-47

Coles, S. L.; DeFelice, R. C.; Eldredge, L. G.; Carlton, J. T. (1999b) Historical and recent introductions of non-indigenous marine species into Pearl Harbor, Oahu, Hawaiian Islands., Marine Biology 135(1): 147-158

Coles, S. L.; DeFelice, R. C.; Minton, D. (2001) Marine species survey of Johnston Atoll, Central Pacific Ocean, June 2000, Bishop Museum Technical Report 19: 1-59

Coles, S. L.; Reath, P. R.; Longenecker, K.; Bolick, Holly; Eldredge, L. G. (2004) <missing title>, Hawai‘i Community Foundation and the U. S. Fish and Wildlife Service, Honolulu. Pp. 1-187

Cortes, Jorge (2012) Marine biodiversity of an Eastern Tropical Pacific oceanic island, Revista Biologia Tropical 60(Suppl. 3): 131-183

Florida Museum of Natural History 2009-2013 Invertebrate Zoology Master Database. <missing URL>

Golding, Rosemary E.; Bieler, Rüdiger; Rawlings, Timothy A.; Collins, Timothy M. (2014) Deconstructing Dendropoma: A systematic revision of a worldwide worm snail; group, with descriptions of new genera (Caenogastropoda; Vermetidae), Malacologia 57(1): 1-97

Gonzalez, Angel Javier Vega y Aida (2002) [Mollusks of the Pacific Coast of Veragua, Part II Gastropoda), Technociencia 4(1): 23-45

Hadfield, M. G.; Kay. E.M.; Gillete, M. U.; Lloyd, M. C. (1972) The Vermetidae (Mollusca: Gastropoda) of the Hawaiian Islands*, Marine Biology 11: 81-98

Jebakumar, Prince; Prakash ;Nandhagopal, Ganesan; Ragumaran, Shunmugavel; Rajanbabu, Bose; VRavichandran, Vijaya (2015) First record of alien species Eualetes tulipa (Rousseau in Chenu, 1843) from the Royapuram fishing harbour at Chennai,, BioInvasions Records 4(5): 201-204

Miloslavich, Patricia, Klein, Eduardo; Penchaszadeh, Pablo Miloslavich (2010) Gametogenic cycle of the tropical vermetids Eualetes tulipa and Dendropoma corrodens (Mollusca: Caenogastropoda: Vermetidae, Journal of the Marine Biological Association of the United Kingdom 90(3): 509-518

Rosenberg, Gary 1995-2023 Malacolog 4.1.

Spotorno-Oliveira, Paula; Coutinho, Ricardo; de Souza Tâmega, Frederico Tapajós (2018) Recent introduction of non-indigenous vermetid species (Mollusca, Vermetidae) to the Brazilian coast., Marine Biodiversity 48: 1931-1941
DOI 10.1007/s12526-017-0702-7

Stillman, R. A. ; Wood, K. A. Gilerson,W.; Elkinton, E. ; Black, J. M. ; Ward, ,D. H.; Petrie, M. (2015) Predicting effects of environmental change on a migratory herbivore, Ecosphere 6(7): Published online

Strathmann, Meguni F.; Strathmann, Richard R. (2006) A vermetid gastropod with complex intratracapsular cannibalism of nurse eggs and sibling larvae and a high potential for invasion., Pacific Science 60(1): 97-109

Tan, Siong Kiat; Loh, Rebecca K.; Ng, Ting Hui (2021) First record of the worm snail Eualetes tulipa (Rousseau in Chenu, 1843) in Southeast Asia, BioInvasions Records 10(3): 605-611

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database.

WoRMS Editorial Board 2022-2024 World Register of Marine Species.