PERSISTENT TIDAL CYCLES OF SPONTANEOUS MOTOR ACTIVITY IN THE FIDDLER CRAB, UCA PUGNAX

Abstract

The spontaneous running activity of groups of U. pugnax, was recorded under constant laboratory conditions during the summers of 1955 and 1956. This sp. shows an overt rhythm of activity of tidal frequency which remains precise on a day-to-day basis for at least a week. This rhythm seems an excellent one with which to study experimental modifications of persistent tidal rhythms.