Predator associated morphology in Galaxias platei in Patagonian lakes
MILANO, DANIELA; CUSSAC, VÍCTOR. E.; MACCHI, PATRICIO J.; RUZZANTE, DANIEL E.; ALONSO, MARCELO F.; VIGLIANO, PABLO H.; DENEGRI, MARÍA A.
JOURNAL OF FISH BIOLOGY
Blackwell Publishing Ltd (www.blackwellpublishing.com)
Lugar: Inglaterrra; Año: 2002 vol. 61 p. 138 - 156
Among 158 Galaxias platei individuals, collected from nine deep Andean lakes and from oneshallow lake on the Patagonian steppe, morphological characters associated with caudal finlength were negatively correlated with predation intensity as measured by the incidence ofpiscivory. Fish from lakes with high rates of piscivory had relatively short caudal fins and thosefrom lakes with low piscivory had long caudal fins. It is hypothesized that in this species caudalfin length affects swimming ability and thus, ability to escape from predators. The populationof G. platei from Lake Espejo with an intermediate level of piscivory contained individuals withboth long and short caudal fins. Morphological variation within this lake was related to theexploitation of food resources and habitat; individuals with shorter tails ate more amphipodsand inhabited shallower habitats. The results indicated that while the among-lakes morphologicalvariation in G. platei was influenced largely by differences in predation intensity,within-lake morphological variation, where predation was intermediate, appeared to be affectedby both predation and differences in the exploitation of food resources.