Larval Fish Feeding: Strategies for Capturing Prey

It is estimated that over 90 percent of larval fish die due to starvation. Observations have shown that young larval fish, such as the clownfish Amphiprion ocellaris, progress though varying styles of capturing prey. Even over the span of 20 days, larvae of A. ocellaris transition through methods of charging, biting, and sucking-in prey. To aid in interpreting the fish’s behavioral adaptations for successfully capturing prey, we have developed a simplified model that accounts for the hydrodynamic disturbances generated by the fish and the reactivity of the prey to those disturbances. Given the physical parameters of a fish, centered mostly around experimentally-measured values, the model computes the positions of both fish and copepod over time. From these positions, it predicts when the copepod detects the attack and when the copepod gets captured. The results of the model suggest that, even if the fish achieves a relatively high acceleration, capture cannot occur without either jaw-protrusion or the generation of suction. Further evaluation may help quantify the morphological limitations a fish larva may face during development and propose an explanation as to how a larval fish optimizes.