| Species | Recipient region | Date of the first record | |
|---|
| Oithona davisae | Greece / Eastern Mediterranean | 2018 |  |
| Oithona davisae | Bulgaria | 2009 | |
| Oithona davisae | Georgia | 2007 | |
| Oithona davisae | Romania | 2010 | |
| Oithona davisae | Russia / Black Sea | 2003 | |
| Oithona davisae | Ukraine / Black Sea | 2001 | |
| Oithona davisae | Germany / North Sea | 2008 | |
| Oithona davisae | Italy / Central Mediterranean | 2014 | |
| Oithona davisae | Italy / Western Mediterranean | 2014 | |
| Oithona davisae | Italy / Adriatic Sea | 2014 | |
| Oithona davisae | Denmark / North Sea | 2023 | |
| Oithona davisae | Denmark / Baltic Sea | 2023 | |
