Unidentified species

After photographing an Anemone Hermit crab (Dardanus pedunculatus) I noticed a large number of Amphipods ( I think they are Amphipods) in the image on the back of the crab. Some are in the tentacles of the anemone ( Verrillactis paguri) where they seem quite at home.

I checked through all my images of the Anemone Hermit crab and in the images taken in the shallows of Anemone Hermit crabs, the same Amphipods are in the anemones and on the shell but not as many as on this specimen. In the images taken in the deeper waters I cannot see any of them. Would be interested to know if anyone has heard of these Amphipods or if they can be identified.