| anguilla | | ichthyocotylurus platycephalus | species | 0 | 1 |
| canada | ontario | ichthyocotylurus pileatus | species | 2 | 0 |
| canada | ontario | ichthyocotylurus sp. 3 sal-2008 | species | 3 | 0 |
| canada | quebec | ichthyocotylurus pileatus | species | 12 | 0 |
| canada | quebec | ichthyocotylurus sp. 2 sal-2008 | species | 3 | 0 |
| canada | quebec | ichthyocotylurus sp. 3 sal-2008 | species | 2 | 0 |
| canada | saskatchewan | ichthyocotylurus erraticus | species | 0 | 1 |
| czech republic | | ichthyocotylurus pileatus | species | 3 | 0 |
| finland | | ichthyocotylurus erraticus | species | 3 | 0 |
| finland | | ichthyocotylurus pileatus | species | 2 | 0 |
| finland | | ichthyocotylurus platycephalus | species | 3 | 0 |
| finland | | ichthyocotylurus variegatus | species | 3 | 0 |
| united kingdom | england | ichthyocotylurus erraticus | species | 2 | 0 |
| united kingdom | northern ireland | ichthyocotylurus erraticus | species | 1 | 0 |
| united kingdom | scotland | ichthyocotylurus erraticus | species | 0 | 1 |
| united kingdom | scotland | ichthyocotylurus variegatus | species | 3 | 0 |