NEMESIS Bioregion Distribution:

Native  Introduced  Cryptogenic  Failed

First Non-native North American Marine/Estuarine Record: 2001
First Non-native West Coast Marine/Estuarine Record: 2001
First Non-native East/Gulf Coast Marine/Estuarine Record: 2011

General Invasion History:

Hydroides elegans was originally described from Port Jackson, Sydney, Australia. It is now distributed in tropical-to-warm temperate marine waters throughout the world (Zibrowius 1971; ten Hove 1974; Keough, and Ross 1999; Bastida-Zavala and ten Hove 2002). Its origin is unknown, but is usually presumed to be somewhere in the Indo-Pacific. Molecular studies indicate a high degree of similarity among global populations, probably due to extensive genetic exchange from ship transport (Pettengill et al. 2007). The known global distribution of this tubeworm is additionally complicated by the fact that it was long confused with the Northeast Atlantic species Hydroides norvegica (Zibrowius 1971). Hydroides elegans is considered introduced on both sides of the Atlantic, the Mediterranean Sea, the Northeast Pacific (Mexico-California), Hawaii, Russia, Japan, and New Zealand. In most localities, it is restricted to, or concentrated in, polluted harbors (Zibrowius 1971; Bastida-Zavala 2008).

North American Invasion History:

Invasion History on the West Coast:

On the west coast of North America, Hydroides elegans was first reported from San Francisco Bay, at Mare Island Naval Station, on the hull of the submarine U.S.S. 'Narwhal' (in 1929, Carlton 1979). Established populations were first found in 1931 in Los Angeles-Long Beach Harbors (Zibrowius 1970, cited by Carlton 1979). In southern California, H. elegans was collected from San Diego Bay (1st record 1948) and Marina del Rey (in 1972), and is locally abundant (Carlton 1979; Bastida-Zavala 2008, Ruiz et al., unpublished data). This tubeworm was also collected in the Gulf of California at Bahia de La Paz, Mexico in 1991, where it was abundant (Bastida-Zavala 2008). The southward extent of its range in the Eastern Pacific is not known. In 2001, H. elegans was found on settling plates in Richmond Marina, San Francisco Bay (Blum et al. 2007), extending the northward range of this species in the Eastern Pacific. Live specimens have been found in ship fouling, in Vancouver, British Columbia (Sylvester et al. 2011), but are unlikely to survive that far north.

Invasion History on the East Coast:

Hydroides elegans was found on a boat in 'southern Florida' in 1951 (identified as H. norvegica, Hartman 1952). There are scattered records from Biscayne Bay and Indian River Lagoon (Walters 2001; 2004, Ruiz et al., unpublished data). In 2011, this subtropical worm was surprisingly discovered in Eel Pond, Woods Hole, Massachusetts, in November and December.  It developed extensive colonies and survived the winter of 2011-2012 (ICES Advisory Committee on the Marine Environment 2012; James T. Carlton, personal communications, 2011-2013).

Invasion History on the Gulf Coast:

Hydroides elegans (as H. norvegica) was found on the hull of a boat in Corpus Christi Bay, Texas (Hartman 1952). A specimen was collected from Safe Harbor, Key West, Florida (in 1970, USNM 45242, U.S. National Museum of Natural History 2007). This worm was collected on fouling plates in Tampa Bay in 2002 (Ruiz et al. unpublished data). In Mexican waters, H. elegans was collected in Veracruz, Mexico in 1960 and 1996, and in Campeche in 1999 (Bastida-Zavala and ten Hove 2002).

Invasion History in Hawaii:

Hydroides elegans was first collected in Pearl Harbor, Oahu in 1929 (Straughan 1969 as H. norvegica; Coles et al. 1999) and subsequently found in Kanaohe Bay in 1935 (Straughan 1969).

Invasion History elsewhere in the World:

The earliest record of Hydroides elegans in the Western Atlantic, of which we're aware, is from San Juan, Puerto Rico, in 1942 (Bastida-Zavala and ten-Hove 2002). Hydroides elegans is also introduced and established in Guanabara Bay, Rio de Janeiro, Brazil and Mar del Plata, Argentina (Orensanz et al. 2002). In the Eastern Atlantic, it is known from the Azores (Morton and Britton 2000), Senegal (in 1954, Sourie 1954; Fauvel and Rullier 1957, both cited by Zibrowius 1971), Ghana, (Zibrowius 1971), Luanda, Angola (Kirkegard 1959, cited by Zibrowius 1971), and Cape Town, South Africa (Zibrowius 1971). In England and the Netherlands, H. elegans has occurred only in thermal effluents and heated docks (ten Hove 1974; Zibrouwius and Thorp 1989). Hydroides elegans was an early invader of the Mediterranean, collected in 1888 in the Bay of Naples (Lo Bianco 1893, cited by Zibrowius 1971). It now occurs in harbors throughout the Mediterranean, from France, Spain, Israel, Egypt, and Turkey (Zibrowius 1971; Cornelio and Manzoni 1999; Pancuci-Papadopoulou et al. 2005; Cinar 2006; Galil 2007; US National Museum of Natural History 2008).

Hydroides elegans may be of Indo-Pacific origin (Zibrowius 1971; Pettengill et al. 2007) and is widely distributed in the Indian Ocean and West Pacific, from Mozambique, the Red Sea, and the Persian Gulf, to Indonesia, the Philippines, Australia, China, and Polynesia (Zibrowius 1971; Wang and Huang 1993; Rajagopal et al. 1997; Keough and Ross 1999; US National Museum of Natural History 2000). It is considered to be an introduction in New Zealand (first recorded in 1952, Cranfield et al. 1998), Japan (first record 1932, Asakura 1992), and the Vladivostok area of Russia (reported in 2000, Bagaveeva and Zvyagintsev 2000; Zvyagintsev 2003), where it is confined to thermal effluents. In the Galapagos Islands, it was confined to an Ecuadoran Navy dock on Baltra Island, where it is apparantly introduced (Keppel et al. 2019).