n = 7
| Scientific Name | Author | Valid Name | Family | English Name |
|---|---|---|---|---|
| Oligopus ater | Risso, 1810 | Grammonus ater | Bythitidae | |
| Oligopus claudei | (Torre y Huerta, 1930) | Grammonus claudei | Bythitidae | Reef-cave brotula |
| Oligopus diagrammus | (Heller & Snodgrass, 1903) | Grammonus diagrammus | Bythitidae | Purple brotula |
| Oligopus longhursti | Cohen, 1964 | Grammonus longhursti | Bythitidae | |
| Oligopus niger | Risso, 1827 | Grammonus ater | Bythitidae | |
| Oligopus robustus | (Smith & Radcliffe, 1913) | Grammonus robustus | Bythitidae | |
| Oligopus waikiki | Cohen, 1964 | Grammonus waikiki | Bythitidae |