40-9 Sat Jan 2 Effects of free versus tethered food presentation on axolotl strike velocity Panessiti, C E*; Albert, A; Konow, N; University of Massachusetts Lowell; University of Massachusetts Lowell; University of Massachusetts Lowell Caitlin_Panessiti@student.uml.edu
Aquatic animals used in feeding biomechanics studies are often trained to strike at and procure food that is presented via forceps, instead of catching free-moving food as they would in the wild. It has been suggested that forceps-training of subjects may influence their feeding kinematics, especially movement velocities because as the animals learn that the food is unable to escape, they may not strike at it as fast as they would if the food item was free to move and escape. We sought to determine if forceps-trained axolotls would strike faster at food items that appeared to be free-moving as compared to food items presented via forceps. High speed video recordings were taken of three axolotls feeding on crickets that were presented either via forceps or tied to thin (0.12 mm) and clear weighted monofilament line, and thus appeared untethered to the Axolotl. Recordings of Axolotls feeding on untethered fish were also taken to determine how prey that can easily escape would affect gape velocities during strikes. Mean and peak gape opening and closing velocities were extracted for each food type and presentation and compared using ANOVA. We found no statistically significant differences between the mean and peak gape opening and closing velocities when axolotls fed from forceps as compared to on food that appeared to be untethered (p-values ranged from 0.158 to 0.717). Surprisingly, strikes on goldfish were significantly slower than strikes on crickets, but more data are needed to verify this result as only a few trials were analyzed. These data are important as they show that training aquatic Axolotls to eat off of forceps does not alter movement velocities during feeding but suggest that there may be a kinematics response when different food types are used.