Does color matter? Molecular and ecological divergence in four sympatric color morphs of a coral reef fish

Abstract

Non‐sex‐linked color polymorphism is common in animals and can be maintained in populations via balancing selection or, when under diversifying selection, can promote divergence. Despite their potential importance in ecological interactions and the evolution of biodiversity, their function and the mechanisms by which these polymorphisms are maintained are still poorly understood. Here, we combine field observations with life history and molecular data to compare four sympatric color morphs of the coral reef fish Paracirrhites forsteri (family Cirrhitidae) in the central Red Sea. Our findings verify that the color morphs are not sex‐limited, inhabit the same reefs, and do not show clear signs of avoidance or aggression among them. A barcoding approach based on 1,276 bp of mitochondrial DNA could not differentiate the color morphs. However, when 36,769 SNPs were considered, we found low but significant population structure. Focusing on 1,121 FST outliers, we recovered distinct population clusters that corresponded to shifts in allele frequencies with each color morph harboring unique alleles. Genetic divergence at these outlier loci is accompanied by differences in growth and marginal variation in microhabitat preference. Together, life history and molecular analysis suggest subtle divergence between the color morphs in this population, the causes for which remain elusive.

DNA reconciles morphology and colouration in the drunk blenny genusScartichthys(Teleostei: Blenniidae) and provides insights into their evolutionary history

“…The same reasoning applies for the "two bar front head uncovered" colour pattern. Specimens displaying the "uniform orangebrown" colour pattern are frequently observed in the subtidal kelp, Lessonia trabeculata, down to 20 m depth, and we thus hypothesize that this colouration is involved in camouflage (Gaither et al, 2020). In line with Gaither et al (2020), different colour morphs of S. viridis have been observed together inhabiting the same environments.…”

“…Specimens displaying the "uniform orangebrown" colour pattern are frequently observed in the subtidal kelp, Lessonia trabeculata, down to 20 m depth, and we thus hypothesize that this colouration is involved in camouflage (Gaither et al, 2020). In line with Gaither et al (2020), different colour morphs of S. viridis have been observed together inhabiting the same environments. This colour polymorphism could thus be related to either juvenile stages or microhabitat preferences as both colour morphs are more algae associated (Pérez-Matus et al, 2017;Riquelme-Pérez et al, 2019).…”

DNA reconciles morphology and colouration in the drunk blenny genus Scartichthys (Teleostei: Blenniidae) and provides insights into their evolutionary history

“…In line with Gaither et al . (2020), different colour morphs of S. viridis have been observed together inhabiting the same environments. This colour polymorphism could thus be related to either juvenile stages or microhabitat preferences as both colour morphs are associated with algae (Pérez‐Matus et al ., 2017a; Riquelme‐Pérez et al ., 2019).…”

“…Specimens displaying the “uniform orange‐brown” colour pattern are frequently observed in the subtidal kelp, Lessonia trabeculata , down to 20 m depth. Thus, the authors of this study hypothesize that this colouration is involved in camouflage (Gaither et al ., 2020). In line with Gaither et al .…”

Genome-wide markers reveal differentiation between and within the cryptic sister species, sunset and vermilion rockfish

“…Additionally, RADseq has proven to be an effective tool in identifying and assessing intraspecific differentiation, especially in 1 Vermilion and sunset rockfish are scheduled for a stock assessment in 2021 under the auspices of the PFMC where the two species will be assessed collectively as a complex. cases where traditional markers (i.e., mtDNA and microsatellites) failed to detect signals of structure (Bohling et al 2019;Gaither et al 2020;Longo et al 2020;Morgan et al 2018;Vaux et al 2021;Vendrami et al 2019). Although distinguishing between clear taxonomic units at the level of species is paramount, the identification of significant intraspecific population genetic structure is also important for species-specific management (Bernatchez et al 2017;Hauser and Seeb 2008;Spies and Punt 2015;Waples et al 2008).…”