DOI: 10.5061/dryad.280gb5mn7
title: Data from: Rapid generation of ecologically relevant behavioural novelty in experimental cichlid hybrids

description: The East African cichlid radiations are characterised by repeated and
 rapid diversification into many distinct species with different ecological
 specialisations and by a history of hybridization events between
 non-sister species. Such hybridization might provide important fuel for
 adaptive radiation. Interspecific hybrids can have extreme trait values or
 novel trait combinations and such transgressive phenotypes may allow some
 hybrids to explore ecological niches neither of the parental species could
 tap into. Here, we investigate the potential of second-generation (F2)
 hybrids between two generalist cichlid species from Lake Malawi to exploit
 a resource neither parental species is specialised on: feeding by sifting
 sand. Some of the F2 hybrids phenotypically resembled fish of species that
 are specialised on sand sifting. We combined experimental behavioural and
 morphometric approaches to test whether the F2 hybrids are transgressive
 in both morphology and behaviour related to sand sifting. We then
 performed a quantitative trait loci (QTL) analysis using RADseq markers to
 investigate the genetic architecture of morphological and behavioural
 traits. We show that transgression is present in several morphological
 traits, that novel trait combinations occur, and we observe transgressive
 trait values in sand sifting behaviour in some of the F2 hybrids.
 Moreover, we find QTLs for morphology and for sand sifting behaviour,
 suggesting the existence of some loci with moderate to large effects. We
 demonstrate that hybridization has the potential to rapidly generate novel
 and ecologically relevant phenotypes that may be suited to a niche neither
 of the parental species occupies. Interspecific hybridization may thereby
 contribute to the rapid generation of ecological diversity in cichlid
 radiations.
description: <strong>GenotypeTable_CALxTAE.vcf</strong> contains
 10’166 quality filtered SNPs / genotypes for 126 individuals (114 F2s
 (“CALTAEF2”), 7 CAL (“ASTCAL”) & 5 TAE (“PROTAE”) parental species
 individuals). These are then subset to loci fixed between the parental
 species (see Methods) for linkage map construction.
 <strong>LinkageMap_CALxTAE.txt</strong> gives the
 position of 931 loci on the linkage map.
 <strong>GenoPheno_CALxTAE.csv</strong> contains
 phenotypes and genotypes for 109 F2 individuals in the format for QTL
 mapping in R/qtl. Phenotypes: 5 size corrected linear distances (EpD, EyL,
 LJL, ML, HW), calculated mouth angle (MA), measured standard length (SL),
 shape principal component analysis (PCA) scores (PCs 1-10), strike counts
 for males (M) and females (F), log10(max efficiency) for males, and
 sex.
 <strong>SampleOverview_CALxTAE.csv</strong> lists all
 individuals that were used in this study and in which part of the study
 they were used. Individuals 1-73 and 221-223 are previously preserved
 individuals that had died of natural causes in the aquarium between
 2010-2016.
 <strong>all_fish_219.TPS</strong> and
 <strong>sandsifters_21.TPS</strong> contain the coordinates
 obtained by placing landmarks on photographs in TPSdig 2.10.
 all_fish_219.TPS contains all F2 hybrid and parental species individuals,
 sandsifters_21.TPS the 21 sand sifting species.