Anyone seen one of these before? Very small, only 1/4 inch at the most, yellow with a reddish patch in the center of the body. Seen regularily here in Roatan by a few instructors who know where to find them. Haven't changed in size or appearance for 5 months now. We find them near reddish clumps of algae in sandy or rubble areas at any depth. 

It moves similar to a leechhead shield slug, we've looked at it under a magnifying glass and can see no glands, gills or bumps of any kind.  

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