[2] This shrimp is usually found living in association with the sea anemone Stichodactyla helianthus or occasionally with Condylactis gigantea.

[3] In general it is clear and colourless, but there are many small orange and white spots on the appendages that sometimes lie close together and form bands.

[4] If its usual host is not available, P. rathbunae may associate with the giant Caribbean sea anemone (Condylactis gigantea).

[4] The tentacles of this anemone have a wide range of colouring including white, pink, orange, pale blue and tan, usually with paler tips,[5] and the shrimps associated with it exhibit a limited ability to match their host, with a greater degree of white spotting and with no greenish tinge.

A period of up to five hours is then required to re-establish the immunity, during which time cautious contact is made by the shrimp.