| Species | Recipient region | Date of the first record | |
|---|
| Hydroides elegans | Israel | 1955 |  |
| Hydroides elegans | Greece / Central Mediterranean | 2012 | |
| Hydroides elegans | Greece / Eastern Mediterranean | 1976 | |
| Hydroides elegans | France / Western Mediterranean | To 1944 | |
| Hydroides elegans | Netherlands | 1973 | |
| Hydroides elegans | Italy / Adriatic Sea | 1934 - 1938 | |
| Hydroides elegans | United Kingdom (Britain) / English Channel | 1937 | |
| Hydroides elegans | Italy / Western Mediterranean | To 1850 | |
| Hydroides elegans | Italy / Central Mediterranean | 1964 | |
| Hydroides elegans | Portugal / Azores | To 2000 | |
