Skip to main content
Dryad logo

Data from: Where Am I? Niche constraints due to morphological specialisation in two Tanganyikan cichlid fish species

Citation

Widmer, Lukas; Indermaur, Adrian; Egger, Bernd; Salzburger, Walter (2021), Data from: Where Am I? Niche constraints due to morphological specialisation in two Tanganyikan cichlid fish species, Dryad, Dataset, https://doi.org/10.5061/dryad.9w0vt4bcf

Abstract

Food resource specialisation within novel environments is considered a common axis of diversification in adaptive radiations. Feeding specialisations are often coupled with striking morphological adaptations and exemplify the relation between morphology and diet (phenotype-environment correlations), as seen in, for example, Darwin finches, Hawaiian spiders and, in particular, the cichlid radiations in East Africa. The cichlids’ potential to rapidly exploit and occupy a variety of different habitats has previously been attributed to the variability and adaptability of their trophic structures including the pharyngeal jaw apparatus. Here we report a reciprocal transplant experiment designed to explore the adaptability of the cichlid’s trophic structures in highly specialised cichlid fish species. More specifically, we forced two common but ecologically distinct cichlid species from Lake Tanganyika, Tropheus moorii (rock-dweller) and Xenotilapia boulengeri (sand-dweller), to live on their preferred as well as on an un-preferred habitat (sand and rock, respectively). We measured their overall performance on the different habitat types and explored whether adaptive phenotypic plasticity is involved in adaptation. We found that, while habitat had no effect on the performance of X. boulengeri, T. moorii performed significantly better in its preferred habitat. Despite an experimental duration of several months we did not find a shift in the morphology of the lower pharyngeal jaw bone that would be indicative of adaptive phenotypic plasticity in this trait.