Response curves and free-running period of the circadian locomotor rhythm of Talitrus saltator (Crustacea: Amphipoda)

The amphipod, Talitrus saltator is a supralittoral species inhabits non-permanent burrows along the sandy beach. Its locomotor activity rhythm is largely studied in several beaches and by several authors. The present study was performed in order to better understand the limits of entraining of the locomotor rhythm of this species. The recording was carried in 30 specimens maintained individually, for the first six days in continuous darkness followed by light pulses of 3 h in constant darkness entraining all hours of the day, six days of recording separates the two successive pulses. After the experiment, the phase response curve is constructed to determine the sensitivity of this nocturnal species to light pulses.