Contrasting effects of environmental factors during larval stage on morphological plasticity in postmetamorphic frogs

TEJEDO, M.; MARANGONI. F.; PERTOLDI, C.; RICHTER-BOIX, ALEX; LAURILA, ANSSI; ORIZAOLA, GERMÁN; NICIEZA, A. G.; ÁLVAREZ, DAVID.; GOMEZ- MESTRE, IVÁN

CLIMATE RESEARCH

INTER-RESEARCH

Año: 2010 vol. 43 p. 31 - 39

0936-577X

In organisms with complex life cycles, environmentally induced plasticity across sequential stages can have important consequences on fitness related traits such as developmental and growth rates. However, also other related traits such as morphology can be also affected although previous research in amphibians and other ectothermic vertebrates suggested that size-independent metric shapes were generally insensitive to environmental inductions. We conducted a literature survey to examine the allometric responses in relative hind-leg length and head shape of postmetamorphic anuran amphibians to induced environmental (temperature, resource level, predation and desiccation risk) changes operating during the larval phase in 44 studies using 19 species. To estimate and compare plastic responses across studies we employed both an index of plasticity that provides a percentage of change, and effect sizes from a meta-analysis. We found contrasting responses to different environmental cues. Temperature increase induces smaller relative heads but not overall shifts in relative hind legs. An increment in resource availability results in longer hind legs and no change in head shape. Other environmental factors such as increase in predation and desiccation risk determine small but significant reductions in relative hind legs but no clear pattern in allometric plasticity of head. Both hind leg and head shape plasticity in postmetamorphic frogs was positively correlated with growth rate plasticity during the larval stage. However, plasticity of developmental rates was only correlated with head shape plasticity. Overall, the results suggest that environmental variation during the larval stage may significantly influence the morphology of hind legs and head that indirectly may affect the performance of postmetamorphic frogs and therefore, predicted induced changes by global warming both in both pond temperature and pond desiccation may have morphological consequences in metamorphic frogs.