1 3/4 inch
(read in your best Attenborough voice) Translucent and jewel-like the amethyst nudibranch slowly moves across the sea floor. If you are lucky enough to see it swimming freely you will get a glimpse of its highly patterned foot and the feathery edge of its mantle, the organ its uses to extract oxygen from the water… this little guy keeps its lungs on the outside.