The energy cost of migration of the bivalveDonaxon tropical sandy beaches

Abstract

1. The energy cost involved in tidal migration on tropical sandy beaches by the bivalves Donax incarnatus Gmelin and D. denticulatus L. is estimated from observations and recordings of the burrowing movements involved. >2. The maintenance of position between migratory movements requires expenditure of more energy than does emergence and re‐burial during migration. Together these two components of activity require in an animal of 2 cm shell length, 6 cal/day for D. denticulatus and 6.6 cal/day for D. incarnatus. 3. In D. incarnatus the daily oxygen consumption of an animal of this size is 0.25 mg O2/animal which is equivalent to a maintenance requirement of 20.4 cal/day, so that migration may add about one‐third to the daily maintenance requirement. 4. For the mole crab, Emerita holthuisi Sankolli from the same beach as D. incarnatus, comparable figures for the energy requirements of migration and maintenance are 1.14 cal/day and 27.2 cal/day.