We hypothesise that the body shapes of three mudskipper species (Boleophthalmus dussumieri, Periophthalmus waltoni, and Scartelaos tenuis) are ecomorphological adaptations to different epi- and infaunal habitats. We investigated: (i) the association between burrow density and selected ecological variables; (ii) the phylogenetic relationships among these species, based on two mtDNA and one nDNA markers; (iii) their geometric morphometrics and ancestral shape reconstructions, based on two-dimensional landmark configurations; and (iv) their body surface-to-volume ratios (SAV), based on a geometric model. Boleophthalmus dussumieri and S. tenuis are more closely related, and more elongated than P. waltoni; the body of S. tenuis also has a higher SAV, and its elongated shape appears to be a divergent trait. P. waltoni is found in a wide range of conditions, including vegetated habitats; B. dussumieri is associated with low-energy conditions and fine unvegetated deposits; and S. tenuis is associated with high-energy conditions and coarser, non-cohesive sediments. These results suggest that body elongation in Scartelaos species is a divergent locomotory adaptation to marine habitats characterised by semi-liquid and less cohesive sediments. The more compact body shape of Periophthalmus species is hypothesised to have evolved from a gobionelline ancestor, and is proposed to be a preadaptation to subaerial locomotion in semi-terrestrial habitats.
Mudskipper image data
Original images of the specimens used (n=9 for Boleophthalmus dussumieri; n=10 for Periophthalmus waltoni; n=12 for Scartelaos tenuis).
mudskipper_image_data.zip
Mudskipper TPS data
Landmark coordinate data of mudskipper digital images obtained using tpsDig v. 2.16.
mudskipper_tpsdata.zip
Mudskipper maximum likelihood and Bayesian phylogenetic trees
RAxML_bipartitions.persian_mudskippers.TRE contains the maximum likelihood phylogenetic tree of 19 fish species. BIpersian_mudskippers.TRE contains the Bayesian phylogenetic tree for the same 19 fish species. mudskipper_three_species_ML_tree.NWK contains the maximum likelihood phylogenetic tree for Boleophthalmus dussumieri, Periophthalmus waltoni, and Scartelaos tenuis inferred from the tree given in RAxML_bipartitions.persian_mudskippers.TRE. All tree data are specified in Newick tree format.
mudskipper_phylogeny_ML_Bayesian.zip
Mudskipper ecological data
The ecological data given in Table 1 of the manuscript. Column 1 gives the abbreviated location name of the study plots; Column 2 gives their geographic coordinates. Abbreviations for the ecological variables: B, P, S = number of burrows per square metre of each species; B = B. dussumieri; P = P. waltoni; S = S. tenuis; F = fluvial action; Sc = weight percent fraction of sand; Sd = sediment type; T = tidal action; V = density of the root network; W = wave action.
mudskipper_ecological_data.csv
Mudskipper morphometric data
The file contains data of morphometric variables for all 31 mudskipper specimens. Column 1: specimen label identification; Column 2: species name. Abbreviations: BD = body depth; LPD = least depth of caudal peduncle; HD = head depth; PAL = post-anal tail length; PDL = predorsal length; INT = internal length; SL = standard length; Sa = surface area of region a; Sb = surface area of region b; Sc = surface area of region c; St = total surface area; Va = volume of region a; Vb = volume of region b; Vc = volume of region c; Vt = total volumel; SAVa = surface area to volume ratio of region a; SAVb = surface area to volume ratio of region b; SAVc = surface area to volume ratio of region c; SAVt = total surface area to volume ratio
morphometric_data.csv
Mudskipper Procrustes shape variable matrix
The matrix of Procrustes shape variables after application of Generalized Procrustes Analysis as implemented via the gpagen function of the geomorph R package (version 3.0.0). The dimension of the matrix is 31x28 (31 specimens, 14 landmarks).
mudskipper_Procrustes_shape_variable_matrix.csv
Mudskipper outline TPS data file
The TPS data file containing the coordinates of the 14 landmarks from the mean shape configuration followed by semi-landmarks defining the outlines of the body, the mouth, and the eye.
consensusBPS.TPS
Mudskipper concatenated multiple sequence alignment
Concatenated multiple sequence alignment of cox1-cytb-rag1 DNA sequences from 19 species of fish in Nexus file format.
Persian_mudskippers_MSA.nxs
Mudskipper project R codes I
Major R codes for reproducing analyses in the manuscript.
mudskipper_analysis.R
Mudskipper project R codes II
Minor R code for generating the outline of the mudskipper.
outline_generation.R
Raw sediment analysis results
The analyses in this file form the bases for subsequent construction of the sediment-related ecological variables Sd = sediment type, and Sc = weight percent fraction of sand, which are ordinal.
Sediment analysis raw.xlsx
Categorisation of sediment-related ecological variables
This file explains how the ordinal scales of the sediment-related ecological variables were ascertained for each sampling site, based on the results of the raw sediment analysis.
Sediment analysis ordinal variable.xlsx