Alex Mustard / Butterfish (Pholis gunnellus) portrait. Gardur, south west Iceland. North Atlantic Ocean.

Alex Mustard / Portrait of a butterfish (Pholis gunnellus) in seaweeds, on a chalk reef. Sheringham, north Norfolk, England, United Kingdom. North Sea

Graham Eaton / Two Shannies (Lipophrys pholis) in a tidepool with barnacles on rock, Nefyn, Gwynedd, Wales, July.

Andy Jackson / 2020VISION / Butterfish (Pholis gunellus) swimming alongside the wreck of the Endeavour, Kirkwall Bay, Orkney, Scotland, UK, June 2011.

Alex Mustard / Butterfish (Pholis gunnellus) portrait. Gardur, south west Iceland. North Atlantic Ocean.

Robert Thompson / Butterfish (Pholis gunnellus) in rock pool, St John's Point, near Kilough, County Down, Northern Ireland, February 2013

Alex Hyde / Butterfish / Gunnel (Pholis gunnellus) against white background. From the Isle of Skye, Inner Hebrides, Scotland, UK.

Todd Mintz / Penpoint gunnel (Apodichthys flavidus) Port Hardy, British Columbia, Canada.

Ingo Arndt / Butterfish (Pholis gunnellus) or Gunnell, fifteen centimeters long, Helgoland, Germany

David Fleetham / Longfin gunnel (Pholis clemensi) resting on tubeworm covered rock, British Columbia, Canada, Pacific Ocean.

Alex Mustard / Penpoint gunnel (Apodichthys flavidus) head portrait, Browning Pass, Vancouver Island, British Columbia, Canada, Pacific Ocean.

Terry Whittaker / Black guillemot (Cepphus grylle) brings butterfish (Pholis gunellus) prey to its nest within harbour wall, Portpatrick Harbour, Scotland, May.