| Family | Aegidae White, 1850
| 14 272 | Genera Species |
| Family | Anuropidae Stebbing, 1893
| 1 10 | Genus Species |
| Family | Barybrotidae Hansen, 1890
| 1 2 | Genus Species |
| Family | Capitoniscidae Boyko & Williams, 2023
| 2 4 | Genera Species |
| Family | Corallanidae Nunomura, 2006
| 12 121 | Genera Species |
| Family | Cryptoniscidae Kossmann, 1880
| 15 60 | Genera Species |
| Family | Cumoechidae Boyko & Williams, 2023
| 1 1 | Genus Species |
| Family | Cymothoidae Leach, 1818 Fish Doctors, Tongue Biters | 75 672 | Genera Species |
| Family | Gastrodoridae van Bakel, Fraaije, Jagt & Artal, 2008
| 1 1 | Genus Species |
| Family | Gnathiidae Leach, 1814
| 21 391 | Genera Species |
| Family | Protognathiidae Wägele & Brandt, 1988
| 1 2 | Genus Species |
| Family | Stellatoniscidae Oanh & Boyko, 2020
| 1 2 | Genus Species |
| Family | Tridentellidae Bruce, 1984
| 2 28 | Genera Species |
| Genus | Chimaeroniscus Williams, Boyko & Moritaki, 2022
| 1 | Species |
| Genus | Thermaloniscus Bourdon, 1983
| 0 | Species |