ECOLOGICAL DETERMINANTS OF BIOECONOMICS IN 3 INTERTIDAL CHITONS (ACANTHOPLEURA SPP)

Organization of foraging in time and space was assessed in 3 species of chitons (Mollusca: Polyplacophora)<>9d\Acanthopleura gemmata, Indian and Pacific Ocean; A. brevispinosa, Western Indian Ocean; A. granulata, Caribbean Sea<>9d\which experience different intertidal conditions. The species exhibit a different bioeconomical organization: central place foraging based on homing and zonal shuttling (A. gemmata), alternance of homing and dispersive movements (A. brevispinosa), and prevalence of ranging pattern (A. granulata). Both spatial variables (mainly related to the amplitude of tidal oscillations and exposure to waves) and temporal ones (related to diel and tidal environmental oscillations) account for the observed interspecific differences in movement patterns. The utmost importance of spatial parameters (and related modification in shelter availability and exposure to predators) in shaping the specific foraging behaviour is revealed. -from Authors