title: Flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newtLissotriton vulgaris.
abstract: Transitions between aquatic and terrestrial habitats are significant steps in vertebrate evolution. Due to the different biophysical demands on the whole organism in water and air, such transitions require major changes of many physiological functions, including feeding. Accordingly, the capability to modulate the pre-programmed chain of prey-capture movements might be essential to maintain performance in a new environment. Newts are of special interest in this regard as they show a multiphasic lifestyle where adults change seasonally between an aquatic and a terrestrial stage. For instance, the Alpine newt is capable of using tongue prehension to feed on land only when in the terrestrial stage, but still manages to suction feed if immersed whilst in terrestrial stage. During the aquatic stage, terrestrial feeding always involved grasping prey by the jaws. Here, we show that this seasonal shift in feeding behavior is also present in a species with a shorter terrestrial stage, the smooth newtLissotriton vulgaris. Behavioral variability increases when animals change from aquatic to terrestrial strikes in the aquatic stage, but prey-capture movements seem to be generally well-coordinated across the feeding modes. Only suction feeding in the terrestrial stage was seldom performed and appeared uncoordinated. Our results indicate that newts exhibit a high degree of seasonal flexibility of the prey-capture behavior. The similarity between movement patterns of suction feeding and terrestrial feeding suggests that only relatively subtle neuromotoric adjustments to the ancestral, suction-feeding motor program are required to successfully feed in the new environment.
authors.affiliation: Institute of Systematic Zoology and Evolutionary Biology, Friedrich-Schiller-University Jena, Erbertstr. 1, 07743 Jena, Germany ; Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium ; Department of Integrative Zoology, University of Vienna, Althanstr. 14, 1090 Vienna, Austria.
authors.forename: Egon
authors.initials: E
authors.lastname: Heiss
authors.affiliation: Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium ; Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000 Ghent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Aerts
authors.affiliation: Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium ; Evolutionary Morphology of Vertebrates, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Van Wassenbergh
keywords: Amphibia; Behavioral plasticity; Feeding biology; Kinematics; Salamanader