Diet induces phenotypic plasticity of Percichthys trucha (Valenciennes,1833) (Perciformes, Percichthyidae) in Patagonia

CRICHIGNO S.A., ; M. Á. BATTINI; V.E. CUSSAC

ZOOLOGISCHER ANZEIGER

ELSEVIER GMBH

Año: 2014 vol. 253 p. 192 - 202

0044-5231

The South American fish genus Percichthys, due to its great morphological variation, has included severalnominal species throughout a long history. However, current genetic analyses signal the existence of onlytwo extant species, Percichthys melanops Girard in Chile (west of the Andes) and P. trucha (Valenciennes) inChile and Argentina (west and east of the Andes). Here the morphological variation of free embryos, larvae,and juveniles of P. trucha was analyzed using linear measurements and geometric morphometrics. Earlymorphological variation and compensatory growth were examined using sibling free embryos and larva.Morphological consequences of experimentally controlled food treatments were explored in juveniles.Our results showed individual variation in the size of the yolk-sac of free embryos and in the duration ofthe mixed feeding period. Phenotypic convergence of the upper jaw length from larva to juveniles andadults, and the causal relationship between diet and head shape was found to change as a consequenceof controlled feeding. Embryonic, larval, and juvenile morphological variation and phenotypic plasticityobserved in P. trucha pinpoint a possible cause for the shape variation observed in the wild. Phenotypicplasticity allows P. trucha to exploit different trophic resources and to occupy different habitats in lowbiodiversity lakes of Patagonia, being a major factor taking part in the past and present success of P.trucha.