| Aponchiidae
| | Synonema triadenophorum | 1 |
| Desmodoridae
| | Acanthopharynx affinis, Acanthopharynx micramphis, Acanthopharyngoides quintus, Zalonema megalosoma | 20 |
| Draconematidae
| | Draconema cephalatum, Draconema ophicephalum, Draconema claparedii | 3 |
| Epsilonematidae
| | Epsilonema cygnoides | 1 |
| Microlaimidae
| | Aponema torosa, Calomicrolaimus parahonestus, Calomicrolaimus honestus, Microlaimus marinus | 4 |
| Monoposthiidae
| | Rhinema exquisitum, Monoposthia costata, Monoposthia mirabilis | 3 |
| Richtersiidae
| | Richtersia iberica, Richtersia vincxae, Richtersia inaequalis | 3 |