Direct measurement and inferred model of rapid growth in a bathyal stalked crinoid from Bahamas Islands

Several specimens of the isocrinid crinoid Neocrinus decorus were collected from a depth of 420 m off Bahamas Islands with the research submersible Johnson Sea Link. To study growth rates, these specimens were ragged, deployed and then recovered 250 days later. The average growth rate of stalk length is 10.8 cm.year(-1) with a maximum value ar 14.3 cm.year(-1). These results allow us to propose a model of growth and regeneration for stalked crinoids in which the energy allocation is modulated through time to the arms and the stalk. Following arm autotomy, in order to re-establish optimum filtration capacity, the animal allocates most of its growth to the crown. (C) Academie des sciences/Elsevier, Paris.