New shrimp from unusual place

Octopuses, we know, eat shrimp. So what was going on when a new species of shrimp was found living in the den of a common octopus (Octopus vulgaris)? In False Bay, South Africa, local divers, a filmmaker, and a scientist collaborated to find three new shrimp species, but the first was the most interesting. In addition to dwelling with the octopus and, for some reason, not being devoured, 
Also of note: the scientist involved, Charles Griffiths, is no newcomer to new species, He has, in fact, described over 100!  Leave some for the rest of us, Charles...

Common octopus (NOAA)