The Effect of Photoperiod on the Orientation and Shell Selection Behavior of the Persian Gulf Hermit Crab, Diogenes avarus (Heller, 1865)

The aim of this study was to investigate the orientation and shell selection behavior of hermit crab Diogenes avarus under different photoperiod situations (6L: 18D, 12L: 12D, 18L: 6D) after 48 hours. The results showed that the light affected the orientation and shell selection behavior of hermit crab Diogenes avarus. This means that the orientation of the control group were uniform (P >0.05), but their orientation in different lighting regimes compared with control, were non-uniform (P0.05). However, by increasing the time of lighting 18L: 6D, hermit crab orientation toward the target was significantly decreased (P