Morphology and behavior of the feeding apparatus in Cryptobranchus alleganiensis (Amphibia: Caudata)

Abstract

Cine and high-speed videographic analyses of feeding in Cryptobranchus alleganiensis demonstrate that prey are captured by either inertial suction or a strike combined with suction. Movements of cephalic elements during capture are generally similar to those of other suction-feeding vertebrates but more variable than those of most aquatic salamanders. Following capture, prey frequently are manipulated and transported into and out of the buccal cavity across the teeth. Specific features of the skull, mandibles, hyoid apparatus, and cephalic musculature of Cryptobranchus correlate directly with behavior. Although the skull is massive, sutures of the anterior braincase permit limited torsion, the maxillae move on their attachments to the braincase, and left and right mandibles are separated by elastic connective tissues. These features provide flexibility and permit asynchronous and asymmetric movements of the mandibles. Equivalent asymmetry and asynchrony of hyobranchial movements are also correlated with specific structural arrangements that may be neither paedomorphic nor primitive. Its feeding mechanics suggest that Cryptobranchus represents a unique and highly derived condition among salamanders. Its ability to modulate movements of the left and right sides of its head argues strongly for the existence of bilaterally asynchronous motor patterns, and patterns of force generation, similar to but much faster than those employed in mammalian mastication. © 1994 Wiley-Liss, Inc.

Activation patterns of the tongue-projector muscle during feeding in the imperial cave salamanderHydromantes imperialis

“…Modulation of prey-capture behavior has been observed previously in many groups of salamanders (Erdman and Cundall, 1984;Shaffer and Lauder, 1985;Miller and Larsen, 1990;Lauder, 1989, 1992;Elwood and Cundall, 1994) plethodontid salamanders (Larsen and Beneski, 1988;Maglia and Pyles, 1995;Deban, 1997), which have extremely fast and long-distance tongue protraction. Bolitoglossine plethodontids were previously thought to be highly stereotyped in their feeding movements, based on morphology and on EMG and force recordings in Bolitoglossa occidentalis (Thexton et al, 1977).…”

Masters of change: seasonal plasticity in the prey-capture behavior of the Alpine newtIchthyosaura alpestris(Salamandridae)

“…Suction feeding is used by all larval salamanders to capture prey and is likely the most ancestral aquatic prey-capture mode for salamanders (Lauder and Reilly, 1994;Reilly, 1996). In adult metamorphosed salamanders that retain an aquatic lifestyle and rely on suction feeding, tongues are small or completely absent to increase oropharyngeal volume that can be filled with water and reduce the turbulence of inflowing water, which is advantageous for hydrodynamics in suction feeding (Özeti and Wake, 1969;Miller and Larsen, 1989;Elwood and Cundall, 1994;Deban and Wake, 2000;Deban, 2003). In contrast, the tongue systems in terrestrial salamanders are well developed and large, as the tongue plays a central role in terrestrial feeding.…”

Linking Morphology and Motion: A Test of a Four‐Bar Mechanism in Seahorses

“…Suction feeding is present in most vertebrate groups, including frogs (Dean 2003), salamanders (Elwood and Cundall 1994), turtles (Van Damme and Aerts 1997), and even mammals (Bloodworth and Marshall 2005). However, suction feeding is ubiquitous in some groups, such as teleost fish (Muller and Osse 1984;Lauder 1985) and elasmobranchs (Wilga et al 2007).…”