Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation

Background: Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits...

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Autores principales: Araújo, M. S., Pérez, Sergio Iván, Magazoni, María Julia C., Petry, Ana C.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2014
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/85627
Aporte de:
id I19-R120-10915-85627
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
Divergent natural selection
Ecological gradients
Hoplias malabaricus
Morphometrics
Poeciliidae
spellingShingle Ciencias Naturales
Divergent natural selection
Ecological gradients
Hoplias malabaricus
Morphometrics
Poeciliidae
Araújo, M. S.
Pérez, Sergio Iván
Magazoni, María Julia C.
Petry, Ana C.
Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
topic_facet Ciencias Naturales
Divergent natural selection
Ecological gradients
Hoplias malabaricus
Morphometrics
Poeciliidae
description Background: Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits associated with changes in growth or absolute size, known as allometry. Livebearing fishes subject to predation gradients have been shown to repeatedly evolve larger caudal peduncles and smaller cranial regions under high predation regimes. Poecilia vivipara is a livebearing fish commonly found in coastal lagoons in the north of the state of Rio de Janeiro, Brazil. Similar to what is observed in other predation gradients, lagoons inhabited by P. vivipara vary in the presence of piscivorous fishes; contrary to other poeciliid systems, populations of P. vivipara vary greatly in body size, which opens the possibility of strong allometric effects on shape variation. Here we investigated body shape diversification among six populations of P. vivipara along a predation gradient and its relationship with allometric trajectories within and among populations. Results: We found substantial body size variation and correlated shape changes among populations. Multivariate regression analysis showed that size variation among populations accounted for 66% of shape variation in females and 38% in males, suggesting that size is the most important dimension underlying shape variation among populations of P. vivipara in this system. Changes in the relative sizes of the caudal peduncle and cranial regions were only partly in line with predictions from divergent natural selection associated with predation regime. Conclusions: Our results suggest the possibility that adaptive shape variation among populations has been partly constrained by allometry in P. vivipara. Processes governing body size changes are therefore important in the diversification of this species. We conclude that in species characterized by substantial among-population differences in body size, ignoring allometric effects when investigating divergent natural selection 's role in phenotypic diversification might not be warranted.
format Articulo
Articulo
author Araújo, M. S.
Pérez, Sergio Iván
Magazoni, María Julia C.
Petry, Ana C.
author_facet Araújo, M. S.
Pérez, Sergio Iván
Magazoni, María Julia C.
Petry, Ana C.
author_sort Araújo, M. S.
title Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
title_short Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
title_full Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
title_fullStr Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
title_full_unstemmed Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
title_sort body size and allometric shape variation in the molly poecilia vivipara along a gradient of salinity and predation
publishDate 2014
url http://sedici.unlp.edu.ar/handle/10915/85627
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