Meeting Abstract
P1.74 Friday, Jan. 4 Predicting three-dimensional predator accuracy during dynamic capture events in centrarchid fishes KANE, E.A.*; HIGHAM, T.E.; University of California, Riverside; University of California, Riverside ekane001@ucr.edu
Strike accuracy is likely a key aspect of prey capture success and can be altered by both the predator and prey. Accuracy is commonly measured using methods that do not account for hydrodynamics, use immobile prey, or constrain predators to a small area. Using data from a PIV analysis of accuracy in centrarchids, the shape of the ingested volume of water (IVW) was predicted in 2D using predator ram speed and peak gape. We have expanded this model to 3D kinematics, and applied it to dynamic prey capture events where both predators and prey are able to perform more natural feeding and escape behaviors. A 3D diamond shape, with the predicted length and height (height was also used as depth) of the IVW, approximated the rounded shape of the parcel of water. The center of the IVW was determined, and distance to the prey (dp) and the boundary (db) were used to calculate accuracy index as AI = 1 – (dp/db). Compared to published 2D data for centrarchids, predator ram speeds determined from 3D kinematics were greater when capturing live, untethered fish prey in an unconstrained environment. These factors resulted in lower AI scores than those published previously. However, the shape of the ingested volume became longer and narrower with increased speed, representing a continuation of the relationship found at lower ram speed in 2D. Therefore, the predicted accuracy determined from 3D unconstrained trials is valid. This method represents an innovative way to determine predator accuracy that not only accounts for the hydrodynamics of suction, but can also be used in the absence of PIV techniques. Predicting accuracy during natural feeding events offers the ability to relate functional consequences to behavior, and is important for future analyses of predator-prey interactions in fishes.
