Multiple environmental cues impact habitat choice during nocturnal homing of specialized reef shrimp

Habitat selection is a critical process for animals throughout their life, and adult organisms that travel to forage or mate must reselect habitat frequently. On coral reefs, competition for space has led to a high proportion of habitat specialists. Habitat selection is especially vital for organisms that require specialized habitat; however, research has primarily focused on the initial habitat choice made during the larval/juvenile stage. Here, we analyze habitat selection in the adult sponge-dwelling reef shrimp, Lysmata pederseni. Using a mark-and-recapture technique, belt transects, patch reefs, and cue isolation experiments, this study reveals that adult L. pederseni diurnally reselect habitat and a natural preference exists for specific sponge species and shapes. This natural preference is a function of chemical and morphological cues as well as sponge distribution. As habitat specialists can drive biodiversity, understanding the mechanisms behind habitat selection can inform research and management practices. Is architecture more important than smell when choosing a home? Here, we investigate the external cues involved in habitat selection of a sponge-associated shrimp after nightly forays on the reef. By tracking shrimp locations through time and isolating environmental variables, we conclude that while both sponge shape and chemical cues play a role in habitat selection, shape may be a more critical factor for resident shrimp.