Reference : Size-related predation reduces intramorph competition in paedomorphic Alpine newts
Scientific journals : Article
Life sciences : Aquatic sciences & oceanology
Life sciences : Environmental sciences & ecology
Life sciences : Zoology
Size-related predation reduces intramorph competition in paedomorphic Alpine newts
Denoël, Mathieu mailto [Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Biologie du comportement - Ethologie et psychologie animale >]
Joly, Pierre [Université Claude Bernard - Lyon 1 - UCLB > > > > > >]
Canadian Journal of Zoology
NRC Research Press
Yes (verified by ORBi)
[en] Size-selective predation ; Food web ; Feeding habits ; Ecology ; Prey ; Alpine newt ; Food specialization ; Resource partitioning ; Diet ; Plankton ; Alpine lake ; Trophic chain ; Predation ; Cohort ; Gape size
[fr] Mesotriton alpestris ; Triton alpestre ; Amphibien
[en] Lac de la cabane ; Ichthyosaura alpestris ; Plankton
[en] Evolutionary theory assumes that facultative paedomorphosis in newts and salamanders is adaptive in allowing either a younger age at maturity or resource partitioning between the heterochronic morphs. In newt populations that only take the metamorphic ontogenetic pathway, juveniles are terrestrial and avoid food competition with larvae and breeding adults. In contrast, in populations where paedomorphosis occurs, branchiate newts of all sizes coexist in the aquatic habitats, posing the question of whether intramorph competition exists and its relationship with the evolution of paedomorphosis. We studied size-related predation in such a size-structured community of branchiate Alpine newts (Triturus alpestris) inhabiting a deep alpine lake. Although gape limitation may explain such size-related predation, individuals also exhibited selectivity according to prey size. Amongst small prey that were within the capture range of all newt size classes, smaller newts preyed on smaller items than did larger ones. We assume that such decisions favour the coexistence of different-sized individuals. It is suspected that such size-selective predation on items which are avoided by water-living metamorphs allows the maintenance of facultative paedomorphosis, in favouring resource partitioning between morphs.
Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS
This paper is published by NRC Research Press

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