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Generalisation within specialization: inter-individual diet variation in the only specialized salamander in the world.

Costa A, Salvidio S, Posillico M, Matteucci G, De Cinti B, Romano A - Sci Rep (2015)

Bottom Line: Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones.Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent.At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

View Article: PubMed Central - PubMed

Affiliation: Consiglio Nazionale delle Ricerche, Istituto di Biologia Agroambientale e Forestale (CNR-IBAF), Area di Ricerca Roma 1, Via Salaria km 29, 300-00015. Monterotondo (RM) (Italy).

ABSTRACT
Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

No MeSH data available.


Related in: MedlinePlus

Vanderploeg and Scavia’s (1979) electivity index E* for the most representative prey categories in autumn (a) and spring (b). n.s. = not significant values.
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f2: Vanderploeg and Scavia’s (1979) electivity index E* for the most representative prey categories in autumn (a) and spring (b). n.s. = not significant values.

Mentions: Salamandrina positively selects only few prey categories, within a relatively large array of available taxa (Fig. 2). In both seasons, Collembola and Araneae are positively selected, while all other prey categories are clearly used less than expected based on their availability (e.g. Acarina). In Autumn, Salamandrina showed a positive selection for more prey categories (Collembola, Coleoptera larvae, Araneae) compared to Spring (Aranea, Collembola).


Generalisation within specialization: inter-individual diet variation in the only specialized salamander in the world.

Costa A, Salvidio S, Posillico M, Matteucci G, De Cinti B, Romano A - Sci Rep (2015)

Vanderploeg and Scavia’s (1979) electivity index E* for the most representative prey categories in autumn (a) and spring (b). n.s. = not significant values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543951&req=5

f2: Vanderploeg and Scavia’s (1979) electivity index E* for the most representative prey categories in autumn (a) and spring (b). n.s. = not significant values.
Mentions: Salamandrina positively selects only few prey categories, within a relatively large array of available taxa (Fig. 2). In both seasons, Collembola and Araneae are positively selected, while all other prey categories are clearly used less than expected based on their availability (e.g. Acarina). In Autumn, Salamandrina showed a positive selection for more prey categories (Collembola, Coleoptera larvae, Araneae) compared to Spring (Aranea, Collembola).

Bottom Line: Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones.Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent.At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

View Article: PubMed Central - PubMed

Affiliation: Consiglio Nazionale delle Ricerche, Istituto di Biologia Agroambientale e Forestale (CNR-IBAF), Area di Ricerca Roma 1, Via Salaria km 29, 300-00015. Monterotondo (RM) (Italy).

ABSTRACT
Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

No MeSH data available.


Related in: MedlinePlus