22/07/2024
This study reveals how different goldfish are from their wild counterparts, with an exceptional morphological diversity among breeds. Divergence and innovations are found in their overall external morphology, skull, hearing structures, and brain, sometimes accompanied by physiological impairments. As with pigeons and dogs, artificial selection for ornamental purposes in goldfish has favoured the acquisition of unique morphologies nonviable in natural environments. However, how goldfish diverge from their wild counterparts is unique, highlighting also a lack of universality in the domestication process.
Open-access - https://academic.oup.com/evlett/advance-article/doi/10.1093/evlett/qrae032/7712283
"Using 21st century tools on a dataset comprising the 16 main goldfish breeds, 23 wild close relatives, and 39 cypriniform species, we show that Charles Darwin’s expressed wonder at the goldfish is justified."
"In goldfish as well, the intensity of breeding selection for ornamental purposes led to major morphological innovation. Some traits have never been recorded in wild specimens, such as the caudal bifurcation of the axial skeleton in twin-tail breeds. Goldfish do not include as many breeds as other domestic animals, but there is considerable morphological diversity in them. In contrast, there are hundreds of recognized breeds of dogs and pigeons. Concerning the time and mode of origin of such diversity, historical sources document how already the Song (960–1279) and Ming (1368–1598) Chinese dynasties record the major kinds of goldfish, including most of the breeds present in our sample from the 15th and 16th centuries."
𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Goldfish phenomics reveals commonalities and a lack of universality in the domestication process for ornamentation
𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Kévin Le Verger, Laurelle C Küng, Anne-Claire Fabre, Thomas Schmelzle, Alexandra Wegmann, Marcelo R Sánchez-Villagra, Goldfish phenomics reveals commonalities and a lack of universality in the domestication process for ornamentation, c, 2024;, qrae032, https://doi.org/10.1093/evlett/qrae032
𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
Domestication process effects are manifold, affecting genotype and phenotype, and assumed to be universal in animals by part of the scientific community. While mammals and birds have been thoroughly investigated, from taming to intensive selective breeding, fish domestication remains comparatively unstudied. The most widely bred and traded ornamental fish species worldwide, the goldfish, underwent the effect of long-term artificial selection on differing skeletal and soft tissue modules through ornamental domestication. Here, we provide a global morphological analysis in this emblematic ornamental domesticated fish.
We demonstrate that goldfish exhibit unique morphological innovations in whole-body, cranial, and sensory (Weberian ossicles and brain) anatomy compared to their evolutionary clade, highlighting a remarkable morphological disparity within a single species comparable to that of a macroevolutionary radiation. In goldfish, as in the case of dogs and pigeons in their respective evolutionary contexts, the most ornamented varieties are extremes in the occupied morphological space, emphasizing the power of artificial selection for nonadaptive traits. Using 21st century tools on a dataset comprising the 16 main goldfish breeds, 23 wild close relatives, and 39 cypriniform species, we show that Charles Darwin’s expressed wonder at the goldfish is justified.
There is a commonality of overall pattern in the morphological differentiation of domesticated forms selected for ornamental purposes, but the singularity of goldfish occupation and extension within (phylo)morphospaces, speaks against a universality in the domestication process.
𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Fully dichotomous phylogeny used in PCoA. We crafted the phylogeny based on the genera in our sample present in the robust molecular phylogeny of Stout et al. (2016), conserving branch lengths. We added goldfish and some Cyprininae to the tree based on the phylogenies of Tang et al. (2011) and Podlesnykh et al. (2015), duplicating the branch lengths of Gymnocypris from the phylogeny of Tang et al. (2011). We forced the dichotomy of incorporated taxa by following the phylogeny of Chen et al. (2020) and the diagrammatic genealogy of Smartt (2008). The production of this tree in addition to the tree shown in Supplementary Figure S2 is justified by the need to incorporate a fully resolved tree for PCoA. As a control test, we provide additional analyses without the incorporation of phylogeny (Supplementary Figure S3). Fish illustrations are not scaled, and references are available in Supplementary Table S7.
© The Author(s) 2024. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEN). Published in Evolution Letters. This paper is released under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. https://creativecommons.org/licenses/by/4.0/
