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Flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newt Lissotriton vulgaris.

Heiss E, Aerts P, Van Wassenbergh S - Org. Divers. Evol. (2014)

Bottom Line: 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.Our results indicate that newts exhibit a high degree of seasonal flexibility of the prey-capture behavior.

View Article: PubMed Central - PubMed

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.

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 newt Lissotriton 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.

No MeSH data available.


Related in: MedlinePlus

Significant correlation plots of kinematic variables. The feeding modes are color-coded: blue (a, b) suction feeding in the aquatic stage, light brown (c, d), jaw prehension in the aquatic stage, and green (e–l) tongue prehension. Note that the second peak hyoid (in h–j) and second peak gape (in h and i) correspond to maximum hyoid depression and maximum gape opening, respectively
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Fig5: Significant correlation plots of kinematic variables. The feeding modes are color-coded: blue (a, b) suction feeding in the aquatic stage, light brown (c, d), jaw prehension in the aquatic stage, and green (e–l) tongue prehension. Note that the second peak hyoid (in h–j) and second peak gape (in h and i) correspond to maximum hyoid depression and maximum gape opening, respectively

Mentions: Similar to timing, we further tested for correlations between peak magnitudes of the above listed kinematic variables of gape and hyoid excursions and found significant correlations between magnitudes of maximum gape opening and maximum hyoid depression in suction feeding in the aquatic stage (r25 = 0.64; P = 0.001), jaw prehension (r25 = 0.56; P = 0.004), and tongue prehension (r25 = 0.76; P < 0.001), but not in suction feeding in the terrestrial stage (r5 = 0.81; P = 0.1). In tongue prehension, we further found significant magnitude correlations between the first gape peak and the first hyoid peak (r25 = 0.56; P = 0.004) and between local minimum gape and maximum tongue protraction (r25 = 0.54; P = 0.005), but there was no correlation between local minimum gape and local minimum hyoid (r25 = 0.17; P = 0.42). All significant correlation plots are shown in Fig. 5. In sum, movements of gape and hyoid (plus tongue and gape movements in tongue prehension) might be regarded as “well-coordinated” in suction feeding in the aquatic stage, jaw prehension, and tongue prehension as movements correlate both chronologically and in magnitudes (though in the latter mode, one variable, local minimum gape and local minimum hyoid, did not correlate in magnitude). By contrast, movements of gape and hyoid in suction feeding in the terrestrial stage were not coordinated.Fig. 5


Flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newt Lissotriton vulgaris.

Heiss E, Aerts P, Van Wassenbergh S - Org. Divers. Evol. (2014)

Significant correlation plots of kinematic variables. The feeding modes are color-coded: blue (a, b) suction feeding in the aquatic stage, light brown (c, d), jaw prehension in the aquatic stage, and green (e–l) tongue prehension. Note that the second peak hyoid (in h–j) and second peak gape (in h and i) correspond to maximum hyoid depression and maximum gape opening, respectively
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4470538&req=5

Fig5: Significant correlation plots of kinematic variables. The feeding modes are color-coded: blue (a, b) suction feeding in the aquatic stage, light brown (c, d), jaw prehension in the aquatic stage, and green (e–l) tongue prehension. Note that the second peak hyoid (in h–j) and second peak gape (in h and i) correspond to maximum hyoid depression and maximum gape opening, respectively
Mentions: Similar to timing, we further tested for correlations between peak magnitudes of the above listed kinematic variables of gape and hyoid excursions and found significant correlations between magnitudes of maximum gape opening and maximum hyoid depression in suction feeding in the aquatic stage (r25 = 0.64; P = 0.001), jaw prehension (r25 = 0.56; P = 0.004), and tongue prehension (r25 = 0.76; P < 0.001), but not in suction feeding in the terrestrial stage (r5 = 0.81; P = 0.1). In tongue prehension, we further found significant magnitude correlations between the first gape peak and the first hyoid peak (r25 = 0.56; P = 0.004) and between local minimum gape and maximum tongue protraction (r25 = 0.54; P = 0.005), but there was no correlation between local minimum gape and local minimum hyoid (r25 = 0.17; P = 0.42). All significant correlation plots are shown in Fig. 5. In sum, movements of gape and hyoid (plus tongue and gape movements in tongue prehension) might be regarded as “well-coordinated” in suction feeding in the aquatic stage, jaw prehension, and tongue prehension as movements correlate both chronologically and in magnitudes (though in the latter mode, one variable, local minimum gape and local minimum hyoid, did not correlate in magnitude). By contrast, movements of gape and hyoid in suction feeding in the terrestrial stage were not coordinated.Fig. 5

Bottom Line: 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.Our results indicate that newts exhibit a high degree of seasonal flexibility of the prey-capture behavior.

View Article: PubMed Central - PubMed

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.

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 newt Lissotriton 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.

No MeSH data available.


Related in: MedlinePlus