| Lampreys (Petromyzontidae) | ||
|---|---|---|
| # | characteristics | results |
| 1a | Sucking disk larger than head, length up to 15 in, may be attached to another fish) | Ichthyomyzon castaneus (Chestnut Lamprey) |
| 1b | Smaller sucking disk length no longer than 7 in | Ichthyomyzon gagei (Southern Brook Lamprey) |