Photo copyright Tim Nicholson.
Common Whelk, Buccinum undatum, laying eggs on a spider crab
Taken on the wreck of the Paddle Wheel, out of Douglas, Isle of Man in winter.
Great British Marine Animals, by Paul Naylor, Deltor (2011)
The Underwater Photographer: Digital and Traditional Techniques, by by Martin Edge, Paperback, 536 pages (2009)