| Common name | Gwyniad |
| Language | Welsh |
| Type | Vernacular |
| Official trade name | No |
| Rank | 2 - (Preferred common name (unique)) |
| Country | England and Wales (UK) |
| Locality | |
| Ref. | Wheeler, A., 1992 |
| Life stage | juveniles and adults |
| Sex | females and males |
| Core | color pattern(s) |
| 1st modifier | |
| 2nd modifier | |
| Remarks | 'gwyn', i.e., 'white' (Tristan Hatton-Ellis, freshwater ecologist, Countryside Council for Wales; Email: t.hatton-ellis@ccw.gov.uk). |