A direct response of the crab Carcinus to the movement of the sun

Abstract

ALTHOUGH it is at first sight unlikely that a crab should take note of the direction of the Sun's movement directly, two lines of evidence already suggest this conclusion. Crabs follow with their eyes the movements of a striped drum which is revolved around them at speeds even lower than one revolution per day1, and several species of lower Crustacea2 as well as the Pacific shore crab H emigrapsus3 utilize some feature of the path of the Sun as a basis for directional escape movements in relation to the local direction of the sea. Show more