Developmental plasticity reveals hidden fish phenotypes and enables morphospace diversification

Abstract

The establishment of a given phenotype is only one expression from a range of hidden developmental possibilities. Developmental plasticity at hidden reaction norms might elicit phenotypic diversification under new developmental environments. Current discussion benefits from empirical analyses that integrate multiple environmental stimuli to evaluate how plastic responses may shape phenotypic variation. We raised Megaleporinus macrocephalus fish in different environmental settings to address contributions of developmental plasticity for emergence of new phenotypes and subsequent morphospace diversification. Plastic morphotypes were evaluated at two complementary scales, the M. macrocephalus morphospace and the higher taxonomic level of Anostomidae family. Morphospace analyses demonstrated that developmental plasticity quickly releases distinct head morphotypes that were hidden in the parental monomorphic population. Plastic morphotypes occupied discrete and previously unfilled morphospace regions, a result obtained from comparisons with a control population and in analyses including several Anostomidae species. Plastic responses involved adjustments in shape and relative position of head bonesets, and fish raised under specific environmental combinations rescued phenotypic patterns described for different genera. Therefore, developmental plasticity possibly contributes to adaptive radiation in Anostomidae. Results illustrate how plastic responses enable morphospace diversification and contribute to evolution.

Phenotypic plasticity guidesMoricandia arvensisdivergence and convergence across the Brassicaceae floral morphospace

“…This is not surprising, considering that the floral forms of this polyphenic species switch between two extremes (G omez et al, 2020). Plasticity-mediated movements across the morphospace have been reported for several other organisms (Pfennig, 2021), like fish (Muschick et al, 2011;Lofeu et al, 2021), ants (Oettler et al, 2019), nematodes (Susoy et al, 2015) and even plants (Barnett et al, 2018). Our case is remarkable because, in contrast to the findings of b) Floral disparity between each of the two phenotypes (i.e.…”

“…Several studies have shown that plasticity may cause the colonization of unfilled regions of the morphospace, contributing to the emergence of morphological novelties (Muschick et al, 2011;Levis et al, 2018;Lofeu et al, 2021). In our case, because Brassicaceae floral morphospace is dense and does not have many empty regions, plasticity allowed M. arvensis to colonize a region of the morphospace already occupied by other species.…”

Phylogeography of Hypomasticus copelandii (Teleostei, Anostomidae) Reveals Distinct Genetic Lineages along Atlantic Coastal Drainages of Eastern Brazil

“…A recent macroevolution study of Characiformes detected a shift to higher speciation rates at the base of the Anostomidae that may have contributed to high levels of modern species diversity in the family [5]. This is also supported by extreme phenotypic plasticity that may have potentialized family speciation processes [81]. Indeed, molecular investigations have found several independent lineages inside Megaleporinus conirostris, M. macrocephalus, M. obtusidens, M. piavussu, M. trifasciatus [38], Laemolyta taeniata [33], Schizodon nasutus, S. vittatus [82], and within the Leporinus desmotes and L. friderici complexes [34,83].…”

Understanding Organisms Using Ecological Observatory Networks

“…To date, comparable work on the drivers of individual phenotypic variation in fish have tended to focus on one or a few specific environmental axes (e.g., Colosimo et al. 2005 ; Lofeu et al. 2021 ; Ronco et al.…”