title: Convergence of life-history phenotypes in a Trinidadian killifish (Rivulus hartii).
abstract: Convergent evolution is characterized by the independent evolution of similar phenotypes within similar selective environments. Previous work on Trinidadian killifish, Rivulus hartii, demonstrated repeatable life-history differences across communities that differ in predation intensity. These studies were performed in rivers located on the south slope of Trinidad's Northern Range Mountains. There exists a parallel series of rivers on the north slope of these mountains. As on the south slope, Rivulus is found across a gradient of fish predation. However, the predatory fish species in north-slope rivers are derived from marine families, whereas south-slope rivers contain a predatory fish fauna characteristic of the South American mainland. If predator-induced mortality and the associated indirect effects are the causal factors selecting for life-history patterns in Rivulus, and these are similar in north- and south-slope rivers, then the specific predatory species should be interchangeable and we would expect convergence of life-history phenotypes across slopes. Here, we characterize the life-history phenotypes of Rivulus from north-slope communities by measuring number of eggs, egg weight, reproductive allotment, reproductive tissue weight, and size at maturity. We find similar patterns of life-history divergence across analogous predator communities. Between slopes, minor differences in Rivulus life-history traits exist and one potential cause of these differences is the abundance of Macrobrachium prawns in north-slope rivers.
authors.affiliation: Department of Biology, University of California, Riverside, CA 92521, USA. andrew.furness@email.ucr.edu
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Furness
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Walsh
authors.forename: David N
authors.initials: DN
authors.lastname: Reznick
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003532:Cyprinodontiformes / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D005260:Female; D020387:Food Chain; D010641:Phenotype; D012098:Reproduction; D045483:Rivers; D012641:Selection, Genetic; D014300:Trinidad and Tobago