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Suction feeding in Chinese giant salamander (free pdf + video)

From: Ben Creisler

A new non-dino paper that may be interest for tetrapod evolution. The
pdf is Open Access.

Egon Heiss, Nikolay Natchev, Michaela Gumpenberger, Anton
Weissenbacher and Sam Van Wassenbergh (2013)
Biomechanics and hydrodynamics of prey capture in the Chinese giant
salamander reveal a high-performance jaw-powered suction feeding
Journal of the Royal Society Interface 10(82) 20121028
doi: 10.1098/rsif.2012.1028

During the evolutionary transition from fish to tetrapods, a shift
from uni- to bidirectional suction feeding systems followed a
reduction in the gill apparatus. Such a shift can still be observed
during metamorphosis of salamanders, although many adult salamanders
retain their aquatic lifestyle and feed by high-performance suction.
Unfortunately, little is known about the interplay between jaws and
hyobranchial motions to generate bidirectional suction flows. Here, we
study the cranial morphology, as well as kinematic and hydrodynamic
aspects related to prey capture in the Chinese giant salamander
(Andrias davidianus). Compared with fish and previously studied
amphibians, A. davidianus uses an alternative suction mechanism that
mainly relies on accelerating water by separating the ‘plates’ formed
by the long and broad upper and lower jaw surfaces. Computational
fluid dynamics simulations, based on three-dimensional morphology and
kinematical data from high-speed videos, indicate that the
viscerocranial elements mainly serve to accommodate the water that was
given a sufficient anterior-to-posterior impulse beforehand by
powerful jaw separation. We hypothesize that this modified way of
generating suction is primitive for salamanders, and that this
behaviour could have played an important role in the evolution of
terrestrial life in vertebrates by releasing mechanical constraints on
the hyobranchial system.

 A video is also available: