Public domain: Introduction events' accounts (50 / 5493)
| Species |
Recipient region |
Date of the first record |
|
| Acrothamnion preissii | Italy / Western Mediterranean | 1969 |  |
| Acrothrix gracilis | France / Western Mediterranean | 1993 | |
| Actaea savignyii | Israel | 2010 | |
| Actaeodes tomentosus | Greece / Eastern Mediterranean | 2013 | |
| Acteocina mucronata | Greece / Eastern Mediterranean | 1991 | |
| Acteocina mucronata | Israel | 1986 | |
| Adelosina carinatastriata | France / Biscay Gulf | To 2007 | |
| Aeolidiella indica | Italy / Western Mediterranean | 1968 | |
| Aequorea macrodactyla | Israel | 2013 | |
| Aerococcus viridans | Ireland | 1961 | |
| Aerococcus viridans | United Kingdom (Britain) / Celtic seas | 1985 | |
| Aeromonas salmonicida salmonicida | Norway / Barents Sea | 1986 | |
| Aeromonas salmonicida salmonicida | Norway / North Sea | 1986 | |
| Aeromonas salmonicida salmonicida | Norway / Norwegian Sea | 1986 | |
| Aetea anguina | Australia / Bass strait | 1887 | |
| Aetea anguina | Spain / Canary Islands | To 2003 | |
| Aetea ligulata | Spain / Canary Islands | To 2003 | |
| Aetea longicollis | Spain / Canary Islands | To 2003 | |
| Aetea sica | Iceland | From 1991 | |
| Aetea sica | Spain / Canary Islands | To 2003 | |
| Aetea truncata | Iceland | From 1991 | |
| Aetea truncata | Spain / Canary Islands | To 2003 | |
| Afrocardium richardi | Israel | 1997 | |
| Afropinnotheres monodi | Portugal / Iberian Coastal | To 2019 | |
| Afropinnotheres monodi | Spain / Iberian Coastal | 1995 | |
| Agardhiella subulata | France / Western Mediterranean | 1984 | |
| Agardhiella subulata | Italy / Adriatic Sea | 2003 | |
| Agardhiella subulata | Italy / Central Mediterranean | 1987 | |
| Agardhiella subulata | Italy / Western Mediterranean | 2007 | |
| Agardhiella subulata | Netherlands | 1998 | |
| Agetus flaccus | Romania | 1994 | |
| Agetus typicus | Romania | 2020 | |
| Aglaothamnion cordatum | Portugal / Azores | 2005 - 2007 | |
| Aglaothamnion feldmanniae | France / Western Mediterranean | 1979 | |
| Aglaothamnion feldmanniae | Italy / Adriatic Sea | 2003 | |
| Aglaothamnion feldmanniae | Italy / Western Mediterranean | 1975 | |
| Aglaothamnion feldmanniae | United Kingdom (Britain) / English Channel | | |
| Aglaothamnion halliae | Denmark / Baltic Sea | 2003 | |
| Aglaothamnion halliae | Denmark / North Sea | 2003 | |
| Aglaothamnion halliae | Germany / North Sea | 1960 | |
| Aglaothamnion halliae | Italy / Adriatic Sea | 2016 | |
| Aglaothamnion halliae | Norway / North Sea | 1980 - 1989 | |
| Aglaothamnion halliae | Sweden / North Sea | 2003 | |
| Ahnfeltiopsis flabelliformis | France / Western Mediterranean | 1995 | |
| Aiptasia diaphana | Portugal / Madeira | 1994 | |
| Aiptasia pulchella | France / Biscay Gulf | 1973 | |
| Aiptasia pulchella | France / Celtic seas | 1974 | |
| Akashiwo sanguinea | Denmark / Baltic Sea | 1983 | |
| Akashiwo sanguinea | Denmark / North Sea | 1982 | |
| Akashiwo sanguinea | Georgia | 2001 | |
