This looks like the ventral surface of Holothuria mexicana after it was disturbed, to me.

On Fri, Mar 14, 2014 at 12:31 PM, Hal Koike <[log in to unmask]> wrote:
Hello everyone,

We are currently conducting a base line sea cucumber assessment in
Carribean, but we came across a Stichopus hermanni looking sea
cucumber. As far as I know S. hermanni is a Indo Pacific species, so I
was wondering what this species could be. If anybody recognize it, I
would greatly appreciate it.

Best wishes,
Hal Koike