Bite Force, Behavior, and Electromyography in the Teiid Lizard, Tupinambis teguixin

Abstract

Abstract We used electromyography (EMG) to investigate bite force production and feeding behavior in five individuals of the teiid lizard, Tupinambis teguixin. Three jaw adductor muscles were tested: pseudotemporalis superficialis (PST), adductor mandibulae externus superficialis (AMES) and pterygoideus (PTY). Force transducer tests determined that mean peak bite force in males (n = 3) was 79 N (22–105 N; n = 24). In females (n = 2), mean peak bite force was 60 N (14–90 N; n = 19). During high-intensity bites, the three muscles tested exhibited synchronous activation patterns, and these activities began before the onset of measured bite forces. Motor activities typically ceased at one-half of the total bite force duration. During natural feeding trials, initial capture bites and crushing bites exhibited motor activity patterns in all three muscles and were similar to those observed during high bite force development. In bites in which the lizards were picking up or moving prey, only the AMES exhibited mot...