Guillet's goby (Lebetus guilleti) is thought to be Europe's smallest marine fish. Records of Guillet's goby in the UK are limited with observations restricted to the Isle of Man, the Plymouth area and Lyme Bay in the English Channel. This species is described for the first time from the Shetland Isles, Scotland, UK where it was documented photographically on two separate occasions in June 2010. On both occasions male and female pairs were photographed on shell gravel in water depths of 10 m and 8 m. These are the first recorded field observations of Guillet's goby in Scotland and extend the known range of this species from 58°N (Kattegat, southern Scandinavia) to 60°N (Shetland). It is probable that species such as Guillet's goby are under-recorded due to their small size, cryptic coloration and behaviour.
