Abstract
The importance of hydrodynamic lift to the autecology of stalked crinoids was evaluated by comparing the maximum hydrodynamic lift experienced by the crinoid crown to the weight of the crinoid in water. Results of the analysis suggest that even under optimum conditions a current velocity of over 20 cm/s would be required to produce enough lift to overcome the animals' weight in water. This implies that under normal conditions crinoids could not function as kites, using the stalk as a tether, unless they possessed some means of reducing their densities. Lift, however, may play a role in the reorientation of crinoids in response to current direction changes, and also in elevating the crown above the substrate following dislodgement or crawling.