Reference : Facultative paedomorphosis as a mechanism promoting intraspecific niche differentiation
Scientific journals : Article
Life sciences : Aquatic sciences & oceanology
Life sciences : Environmental sciences & ecology
http://hdl.handle.net/2268/215147
Facultative paedomorphosis as a mechanism promoting intraspecific niche differentiation
English
Lejeune, Benjamin mailto [Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Biologie du comportement - Ethologie et psychologie animale >]
Sturaro, Nicolas mailto [Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Océanographie biologique >]
Lepoint, Gilles mailto [Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Océanographie biologique >]
Denoël, Mathieu mailto [Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Biologie du comportement - Ethologie et psychologie animale >]
Mar-2018
Oikos
Blackwell Publishing
127
3
427-439
Yes (verified by ORBi)
International
0030-1299
1600-0706
[en] trophic ecology ; food web ; feeding ecology ; resource partitioning ; isotopic niche ; stable isotope ; facultative paedomorphosis ; polyphenism ; polymorphism ; Alps ; Lac de la Cabane ; alpine lake ; alpine newt ; Ichthyosaura alpestris ; Shannon index ; mixing model ; biomass ; diet ; stomach flushing ; predation ; prey ; amphibian ; triton alpestre ; régime alimentaire ; carbon ; nitrogen ; SIBER ; SIAR ; heterogeneous environment ; open niche ; vacant niche ; sexual difference ; sex ; heterochrony ; foraging
[en] Organisms with complex life cycles are characterized by a metamorphosis that allows for a major habitat shift and the exploitation of alternative resources. However, metamorphosis can be bypassed in some species through a process called paedomorphosis, resulting in the retention of larval traits at the adult stage and is considered important at both micro- and macroevolutionary scales. In facultatively paedomorphic populations of newts, some individuals retain gills and a fully aquatic life at the adult stage (paedomorphs), while others undergo complete metamorphosis (metamorphs), allowing for a terrestrial life-stage. Because facultative paedomorphosis affects trophic structures and feeding mechanism of newts, one hypothesis is that it may be maintained as a trophic polymorphism, with the advantage to lessen intraspecific competition during the shared aquatic life-stage. Here, we tested this hypothesis combining stomach content data with stable isotope techniques, using carbon and nitrogen stable isotopes, in facultatively paedomorphic alpine newts Ichthyosaura alpestris. Both stomach content and stable isotope analyses showed that paedomorphs had smaller trophic niches and were more reliant on pelagic resources, while metamorphs relied more on littoral resources, corresponding to a polyphenism along the littoral-pelagic axis and the extension of the population's trophic niche to otherwise ‘underused’ pelagic resources by paedomorphs. Interestingly, stable isotopes revealed that the trophic polyphenism was less marked in males than in females and potentially linked to sexual activity. Although paedomorphosis and metamorphosis are primarily seen as results of tradeoffs between the advantages of using aquatic versus terrestrial habitats, this study provides evidence that additional forces, such as intraspecific trophic niche differences between morphs and trophic niche expansion, may play an important role in the persistence of this dimorphism in heterogeneous environments. Moreover, the different patterns found in males and females show the importance of considering sex to understand the evolutionary ecology of trophic polymorphisms.
Applied and Fundamental FISH Research Center - AFFISH-RC ; Freshwater and OCeanic science Unit of reSearch - FOCUS
F.R.S.-FNRS - Fonds de la Recherche Scientifique ; Fonds Spéciaux de la Recherche (FSR) - Université de Liège
Researchers ; Professionals ; Students
http://hdl.handle.net/2268/215147
10.1111/oik.04714
http://www.oikosjournal.org/blog/forever-young-strategy-niche-differentiation
The paginated published version of this paper is available on Wiley Online Library (see DOI link). The author version is available in open access hereunder.

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