PLoS ONE (Jan 2013)

Functional diversification within a predatory species flock.

  • Edward D Burress,
  • Alejandro Duarte,
  • Wilson S Serra,
  • Marcelo Loueiro,
  • Michael M Gangloff,
  • Lynn Siefferman

DOI
https://doi.org/10.1371/journal.pone.0080929
Journal volume & issue
Vol. 8, no. 11
p. e80929

Abstract

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Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate the ecological and morphological diversification of a recently discovered lotic predatory Neotropical cichlid species flock in subtropical South America. We document morphological and functional diversification using geometric morphometrics, stable C and N isotopes, stomach contents and character evolution. This species flock displays species-specific diets and skull and pharyngeal jaw morphology. Moreover, this lineage appears to have independently evolved away from piscivory multiple times and derived forms are highly specialized morphologically and functionally relative to ancestral states. Ecological speciation played a fundamental role in this radiation and our data reveal novel conditions of ecological speciation including a species flock that evolved: 1) in a piscivorous lineage, 2) under lotic conditions and 3) with pronounced morphological novelties, including hypertrophied lips that appear to have evolved rapidly.