Photo copyright Tim Nicholson.
Female or juvenile Dragonet, Callionymus lyra
Taken in Port Erin, Isle of Man.

A broad, triangular head together with a long snout distinguishes the dragonet from gobies. The female or juvenile seen here blends in with the sandy bed. Males are thought to only breed once in a lifetime and courtship includes the male pulling a face as part of an elaborate display. The fish feed on small animals in the sand like worms and crustaceans.

Read more on diving the Isle of Man
More dragonet photos

Further Reading
Dive sites and marine life of the Calf of Man and neighbouring area by Bill Sanderson, Bruce McGregor and Andrew Brierley, Immel Publishing Ltd, 1994, Paperback.
Great British Marine Animals, by Paul Naylor, Deltor (2011)
The Underwater Photographer: Digital and Traditional Techniques, by by Martin Edge, Paperback, 536 pages (2009)