Meeting Abstract
Suction feeding has evolved independently in two highly disparate systems, aquatic vertebrates and carnivorous bladderworts. Incidentally, bladderworts are the smallest and fastest known suction feeders. Body size has profound effects on aquatic organismal function, including suction feeding. Surprisingly, plant suction feeders appear to have a lower size limit than animal suction feeders. We review how organisms’ solutions to functional challenges is affected by their energy budget. Suction feeding at small size takes enormous energy investment, and as a consequence a minority of tiny organisms can afford to suction feed while most cannot. We address two hypotheses that emerge from this core idea: (1) autotrophic organisms (plants) can afford to pay the price that suction feeding requires because they obtain energy through photosynthesis and feed only for nutrients, and (2) heterotrophic organisms (animals) may not be able to suction feed at a comparable scale as plants due to the energetic costs, and furthermore, may be able to feed at the small end of their size range only by employing supplementary mechanisms such as ram and mouth protrusion. Here we review current knowledge of suction feeding to explore energetic and biomechanical performance limits for aquatic feeders based on morphology and kinematics. The performance outcomes of the complex interplay of size, energetics, and biomechanics can be used to produce a causal, predictive framework for suction feeders that is generalizable beyond the focal organisms.
