| antarctica | | hydractinia sp. pc-2009d | species | 1 | 0 |
| belgium | | hydractinia polyclina | species | 5 | 0 |
| canada | british columbia | hydractinia milleri | species | 2 | 0 |
| chile | | hydractinia sp. mmm-2015 | species | 1 | 0 |
| chile | | hydractinia sp. mmm-2016 | species | 2 | 0 |
| france | bretagne region | hydractinia echinata | species | 3 | 0 |
| france | languedoc-roussillon region | podocoryna pruvoti | species | 42 | 0 |
| france | provence-alpes-cote d'azur region | hydractinia minuta | species | 2 | 0 |
| germany | | hydractinia echinata | species | 2 | 0 |
| iceland | | podocoryna borealis | species | 3 | 0 |
| iceland | southern ppeninsula | hydractinia allmanii | species | 256 | 0 |
| iceland | southern ppeninsula | podocoryna borealis | species | 15 | 0 |
| italy | apulia region | hydractinia cf. calderi mpm-2009 | species | 3 | 0 |
| italy | apulia region | stylactaria fucicola | species | 2 | 0 |
| italy | apulia region | stylactaria inermis | species | 4 | 0 |
| japan | | hydractinia carcinicola complex sp. 3 | species | 1 | 0 |
| japan | | hydractinia epiconcha | species | 1 | 0 |
| japan | | hydractinia multigranosi | species | 1 | 0 |
| japan | hokkaido prefecture | hydrissa sodalis | species | 117 | 0 |
| new zealand | | hydractinia rubricata | species | 1 | 0 |
| new zealand | | podocoryna australis | species | 3 | 0 |
| new zealand | otago | podocoryna australis | species | 2 | 0 |
| new zealand | otago | podocoryna bella | species | 2 | 0 |
| norway | hordaland county | podocoryna borealis | species | 1 | 0 |
| south africa | kwazulu-natal province | hydractinia cf. altispina mpm-2009 | species | 9 | 0 |
| south africa | the western cape province | hydractinia cf. altispina mpm-2009 | species | 2 | 0 |
| spain | balearic islands | hydractinia aculeata | species | 2 | 0 |
| united kingdom | scotland | podocoryna borealis | species | 1 | 0 |
| united states | alaska | hydractinia allmanii | species | 6 | 0 |
| united states | alaska | hydractinia antonii | species | 2 | 0 |
| united states | alaska | hydractinia serrata | species | 2 | 0 |
| united states | california | hydractinia hooperi | species | 1 | 0 |
| united states | california | hydractinia hooperi complex sp. 2 | species | 1 | 0 |
| united states | california | hydractinia laevispina | species | 1 | 0 |
| united states | california | hydractinia milleri | species | 2 | 0 |
| united states | california | hydractinia sp. 1 mpm-2009 | species | 2 | 0 |
| united states | california | hydractinia sp. 3 mpm-2009 | species | 2 | 0 |
| united states | connecticut | hydractinia symbiolongicarpus | species | 59 | 0 |
| united states | florida | hydractinia sp. g.m. | species | 17 | 0 |
| united states | maine | hydractinia polyclina | species | 9 | 0 |
| united states | massachusetts | hydractinia hooperi | species | 1 | 0 |
| united states | massachusetts | hydractinia hooperi complex sp. 1 | species | 1 | 0 |
| united states | massachusetts | hydractinia polyclina | species | 18 | 0 |
| united states | massachusetts | hydractinia symbiolongicarpus | species | 1 | 0 |
| united states | massachusetts | podocoryna americana | species | 8 | 0 |
| united states | new york | hydractinia echinata | species | 3 | 0 |
| united states | new york | hydractinia polyclina | species | 3 | 0 |
| united states | new york | hydractinia symbiolongicarpus | species | 1 | 0 |
| united states | new york | podocoryna americana | species | 1120 | 0 |
| united states | north carolina | hydractinia symbiolongicarpus | species | 2 | 0 |
| united states | washington | hydractinia serrata | species | 1 | 0 |