title: Divergent ontogenies of trophic morphology in two closely related haplochromine cichlids.
abstract: Fish develop morphological specializations in their trophic and locomotor systems as a result of varying functional demands in response to environmental pressures at different life stages. These specializations should maximize particular performances in specialists, adapting them to their trophic and habitat niches at each ontogenetic stage. Because differential growth rates of the structural components comprised in the head are likely to be linked to the diet of a fish throughout its development, we investigated the ontogenetic development of two haplochromine cichlid species belonging to different trophic guilds. We employed geometric morphometric techniques to evaluate whether starting from morphologically similar fry they diverge into phenotypes that characterize trophic guilds and locomotor types. Our examination of overall body shape shows that certain specialized morphological features are already present in fry, whereas other traits diverge through ontogeny due to differences in species-specific allometric variation. Allometric shape variation was found to be more relevant for the biter specialist than for the sucker morphotype. Our results confirm that phenotypic changes during ontogeny can be linked to dietary and habitat shifts in these fish. Furthermore, evidence for an integrated development of trophic and locomotor specializations in morphology was observed.
authors.affiliation: Evolutionary Morphology of Vertebrates, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000, Gent, Belgium.|Integrative Biogeography and Global Change Department, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (MNCN-CSIC), 28006, Madrid, Spain.
authors.forename: Javier H
authors.initials: JH
authors.lastname: Santos-Santos
authors.affiliation: Operational Direction, Taxonomy, and Phylogeny Vertebrates, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000, Brussels, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: Audenaert
authors.affiliation: Operational Direction, Taxonomy, and Phylogeny Vertebrates, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000, Brussels, Belgium.|Evolutionary Ecology Group, Biology Department, University of Antwerp, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Verheyen
authors.affiliation: Evolutionary Morphology of Vertebrates, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000, Gent, Belgium.
authors.forename: Dominique
authors.initials: D
authors.lastname: Adriaens
mesh_terms: D000818:Animals; D005075:Biological Evolution; D023681:Cichlids / Q000033:anatomy & histology* / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D004032:Diet; D017753:Ecosystem; D060106:Lakes; D008124:Locomotion; D013045:Species Specificity
keywords: adaptive radiation; allometry; cichlids; functional morphology; ontogeny