Modulation of prey‐capture behavior in Plethodon cinereus (Green) (Amphibia: Caudata)

Abstract

Many feeding kinematic studies do not identify sources of mechanical variation related to the type or size of prey. Studies of salamanders have concentrated on determining the morphological basis of feeding mechanics or on phylogenetic comparisons; few have examined variability within a species. A series of feeding trials was designed to test whether PZethodon cinereus of different agelsize classes exhibits stereotypic patterns in capturing prey of differing type and size. Stopframe video analyses of feedings were made using 19 salamanders of varying body size and four prey types chosen to resemble items in the natural diet of the species. Five morphological features of each salamander, length and width of prey items, and 15 kinematic variables were used to describe each feeding trial.Statistical analyses of kinematic and morphological variables show that the feeding behavior of this species varies significantly with prey type. Effects of salamander size and prey size within prey types were a source of variation in some kinematic variables; among-individual variation partitioned with salamander body size. Different feeding modes resulted from distinctive combinations of distances from prey, amount of tongue protrusion, body movements, and duration of mouth closure, which varied with the use of jaw prehension and lingual prey capture. Presence of a repertoire of behaviors, composed of versatile combinations of movements, suggests that Plethodon cinereus modulates feeding mechanics to capture different types of prey. Consideration of natural prey in experiments, and of prey type in comparisons made across taxa, are necessary to investigations of the evolution of feeding behaviors.

Dynamics and thermal sensitivity of ballistic and non-ballistic feeding in salamanders

“…These values are low compared with those of plethodontids with elastically powered tongue projection (Deban, 1997;Wake and Deban, 2000;Deban et al, 2007;Deban and Richardson, 2011;Anderson et al, 2014), but consistent with previous studies of Plethodon feeding (Maglia and Pyles, 1995) and similar to other species with attached tongues (Wake and Deban, 2000). The maximum tongue reach observed in Plethodon was 15.6% of SVL.…”

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).…”

Ecological character displacement inPlethodon: Biomechanical differences found from a geometric morphometric study

“…This association can be explained from a functional morphological perspective. Although during prey capture most prey are initially contacted with the tongue, prey size is known to affect feeding mechanics in salamanders (34,35), and in Plethodon in particular (36,37). Large prey items are usually immobilized through rapid closure of the jaws, whereas small prey items continue to the rear of the oral cavity, where they are immobilized through pressure between the tongue and the palatal teeth (33,35).…”