Meeting Abstract

77.4  Sunday, Jan. 6  Prey capture throughout the seasons: functional demands of a multiphasic lifestyle in the Alpine newt Ichthyosaura alpestris (Salamandridae) HEISS, E*; VAN WASSENBERGH, S; University of Antwerp, Belgium; University of Antwerp, Belgium Egon.Heiss@ua.ac.be

Evolutionary transitions between aquatic and terrestrial environments were – and still are – significant steps in vertebrate evolution. These transitions require major changes in most biological functions, including feeding. The Alpine newt, Ichthyosaura alpestris is known to show a “multiphasic lifestyle” where the adult newt changes from a terrestrial to an aquatic life, and again to its terrestrial habitat every year due to its breeding activity. These seasonal transitions induce dramatic changes in morphology, resulting in a distinct aquatic and terrestrial morphotype. We hypothesized that the morphological change between both phases goes along with changes in prey-capture mechanics to maintain performance in both environments. We provide a reconstruction of the complex cranio-cervical myo-skeletal system and simulate its movements during prey-capture. We also analyze the prey capture kinematics in two natural modes (aquatic strike in aquatic phase, terrestrial strike in terrestrial phase) and two induced modes (aquatic strike in terrestrial phase, terrestrial strike in aquatic phase) and perform a multivariate comparison between all 4 modes. In the terrestrial phase, I. alpestris uses its quickly protruding tongue to capture prey, but a suction mechanism when feeding in water. In the aquatic phase, it uses a jaw-based grasping mode on land, but suction feeding underwater. We conclude that I. alpestris shows a so far unknown amount of behavioral plasticity during prey-capture, and that the functioning of its prey-capture system is tuned to seasonal performance demands.