Researchers investigate the evolutionary and biogeographic histories of the early-diverging Herichthyine cichlids, ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐ .
๐(Preprint)
biorxiv.org/content/10.64898โฆ
Results provide evidence of a) unrecognised diversity within ๐๐๐๐โ๐๐๐๐๐ ๐ ๐๐๐ฃ๐๐๐, b) uncertainty in species boundaries in ๐โ๐๐๐๐โ๐กโ๐ฆ๐ , and c) the first report of ghost introgression* in fishes of the northern Neotropics.
* (where genetic material is transferred into a species or population through interbreeding with an extinct or unsampled ancient lineage).
๐ช๐ต๐ฎ๐ ๐ถ๐ ๐ฎ ๐ฃ๐ฟ๐ฒ๐ฝ๐ฟ๐ถ๐ป๐ ๐ฃ๐๐ฏ๐น๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป?
biorxiv.org/content/what-unrโฆ
๐ฅ๐ฒ๐๐ฒ๐ฎ๐ฟ๐ฐ๐ต ๐ง๐ถ๐๐น๐ฒ
Diversifying the Northern Neotropics: Phylogenomics and Evolutionary History of the Early-Diverging Herichthyine Cichlids ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐
๐๐ถ๐๐ฎ๐๐ถ๐ผ๐ป
Diego J. Elรญas, Fernando Alda, Isaรญ Betancourt-Resendes, Alejandro Dรญaz-Flores, Omar Domรญnguez-Domรญnguez, Sheila Rodrรญguez-Machado, Ernesto Velรกsquez-Velรกsquez, Kyle R. Piller, Wilfredo A. Matamoros, Susan F. Mochel, Kevin A. Swagel, Prosanta Chakrabarty, Caleb D. McMahan, Diversifying the Northern Neotropics: Phylogenomics and Evolutionary History of the Early-Diverging Herichthyine Cichlids ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐
bioRxiv 2026.06.05.730467; doi:
doi.org/10.64898/2026.06.05.โฆ
๐๐ฏ๐๐๐ฟ๐ฎ๐ฐ๐
Among Neotropical cichlids the tribe Heroini exhibits substantial ecological diversity and is one of the dominant fish groups across northern Neotropical riverscapes. The majority of studies on heroine cichlids have focused on macroevolutionary patterns but the role of geological and ecological factors shaping lineage diversification within the tribe remains poorly understood.
Here we used ultraconserved elements (UCEs) to infer a taxonomically complete and geographically comprehensive phylogenomic framework of the early-diverging herichthyine sister genera ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐ and to comparatively investigate their evolutionary and biogeographic histories. All our phylogenomic hypotheses support the monophyly of both genera and two species subgroups within ๐โ๐๐๐๐โ๐กโ๐ฆ๐ .
Our results provide evidence of a) unrecognized diversity within ๐๐๐๐โ๐๐๐๐๐ ๐ ๐๐๐ฃ๐๐๐, b) uncertainty in species boundaries in ๐โ๐๐๐๐โ๐กโ๐ฆ๐ , and c) the first report of ghost introgression in fishes of the northern Neotropics. Additionally, our results demonstrate the importance of the Papaloapan and Coatzacoalcos watersheds for fish diversification in the region.
Finally, we show patterns consistent with ecological divergence during the evolution of this group, particularly among sympatric species. Altogether, these patterns suggest that lineage diversification in northern Neotropical cichlids has been driven by the interaction of geological restructuring, climatic and sea-level oscillations, and heterogeneous ecological pressures.
๐ฃ๐ต๐ผ๐๐ผ ๐๐ฟ๐ฒ๐ฑ๐ถ๐
A) Species tree cladogram of the early divergent Herichthyine genera ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐ . A.1-A.3) Alternative phylogenetic relationships between ๐โ๐๐๐๐โ๐กโ๐ฆ๐ ๐ ๐๐๐๐๐๐๐, ๐. โ๐๐๐๐๐๐, and ๐. ๐๐. โ๐๐๐๐๐๐ and support values (UFB: IQTREE 2; LPP: ASTRAL-IV and wASTRAL; bs: Caster-pairs and Caster-sites) recovered for the contentious branch (in light grey) A.4) Normalised quartet scores (NQS) for the alternative relationships between ๐. ๐ ๐๐๐๐๐๐๐, ๐. โ๐๐๐๐๐๐, and ๐. ๐๐. โ๐๐๐๐๐๐. B ) Chronogram of the early diverging herichthyines. * denotes nodes where secondary calibrations were placed for the dating analyses.
ยฉ 2026 the Author(s). Published on the bioRxiv Preprint Server. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence.
creativecommons.org/licensesโฆ
#Herichthyine #Cichlids #Thorichthys #Trichromis #Phylogenomics #EvolutionaryHistory #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Cichlidae #Neotropics #Cichlid #Buntbarsch #Buntbarsche #Heroine #Watersheds #Papaloapan #Coatzacoalcos #Mexico #Belize #YucatanPeninsula #Biogeography
ALT Diego J. Elรญas, Fernando Alda, Isaรญ Betancourt-Resendes, Alejandro Dรญaz-Flores, Omar Domรญnguez-Domรญnguez, Sheila Rodrรญguez-Machado, Ernesto Velรกsquez-Velรกsquez, Kyle R. Piller, Wilfredo A. Matamoros, Susan F. Mochel, Kevin A. Swagel, Prosanta Chakrabarty, Caleb D. McMahan, Diversifying the Northern Neotropics: Phylogenomics and Evolutionary History of the Early-Diverging Herichthyine Cichlids ๐โ๐๐๐๐โ๐กโ๐ฆ๐ and ๐๐๐๐โ๐๐๐๐๐
bioRxiv 2026.06.05.730467; doi: https://doi.org/10.64898/2026.06.05.730467