Our most common nudibranch (sea slug)
Ceratosoma brevicaudatum is a beautiful creature. It is very hard to capture all of its detail in a single image due to its size and the depth of field challenges of macro imaging.
This rear view end shows the detail and complexity of its branchial plume, the organ it uses to breathe with.
Photo: Robert Rath, 'Branchial Fire' 1/200 f/29 ISO100 100mm