Axial skeletal divergence and body depth evolution in an adaptive radiation of crater lake cichlid fishes

Axial skeletal divergence and body depth evolution in an adaptive radiation of crater lake cichlid fishes | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 3 April 2026 V1 Latest version Share on Axial skeletal divergence and body depth evolution in an adaptive radiation of crater lake cichlid fishes Authors : Nicolás Ehemann 0000-0003-1259-1779 , Axel Meyer , and Darrin Hulsey 0000-0002-9653-6728 [email protected] Authors Info & Affiliations https://doi.org/10.22541/au.177521082.26065556/v1 161 views 111 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Fish body depth is a common axis of phenotypic diversification. We investigated the evolutionary relationships between postcranial skeletal divergence and body depth evolution in the Nicaraguan Midas cichlid fish species complex ( Amphilophus spp.). This lineage of at least 13 species has rapidly differentiated and repeatedly ecologically diverged across several crater lake habitats over the past <20,000 years. We used X-ray images to examine the osteological axial skeleton of all named Midas species, as well as several genetically distinct Midas populations endemic to isolated crater lakes. Vertebrae numbers and 14 linear size-adjusted axial skeletal measurements were used for phylogenetically controlled correlations to evaluate whether these traits were highly associated with body depth evolution. Vertebrae morphometric and meristic traits showed little correlation with body depth in these Central American cichlids. However, the depth of the pectoral girdle, several fin proximal pterygiophores, and the hemal and neural spines associated with the axial skeleton were all significantly correlated with Amphilophus body depth. These traits could reflect functional axes along which the Midas cichlid species complex has rapidly and adaptively diversified. Supplementary Material File (figure 1.docx) Download 519.91 KB File (figure 2.docx) Download 760.55 KB File (figure 3.docx) Download 706.92 KB File (figure 4.docx) Download 599.52 KB File (graphical abstract.docx) Download 608.47 KB File (main_document.docx) Download 140.52 KB Information & Authors Information Version history V1 Version 1 03 April 2026 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords evolutionary ecology freshwater natural history vertebrate Authors Affiliations Nicolás Ehemann 0000-0003-1259-1779 University of Konstanz View all articles by this author Axel Meyer University of Konstanz View all articles by this author Darrin Hulsey 0000-0002-9653-6728 [email protected] University College Dublin View all articles by this author Metrics & Citations Metrics Article Usage 161 views 111 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Nicolás Ehemann, Axel Meyer, Darrin Hulsey. Axial skeletal divergence and body depth evolution in an adaptive radiation of crater lake cichlid fishes. Authorea . 03 April 2026. DOI: https://doi.org/10.22541/au.177521082.26065556/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . 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