Geography of speciation affects rate of trait divergence in haemulid fishes

Abstract

Speciation and the interactions between recently diverged species are thought to be major causes of ecological and morphological divergence in evolutionary radiations. Here, we explore the extent to which geographical overlap and time since speciation may promote divergence in marine species, which represent a small fraction of currently published studies about the patterns and processes of speciation. A time-calibrated molecular phylogeny of New World haemulid fishes, a major radiation of reef and shore fishes in the tropical West Atlantic and East Pacific, reveals 21 sister species pairs, of which eight are fully sympatric and 13 are allopatric. Sister species comparisons show a non-significant relation between most of the phenotypic traits and time since divergence in allopatric taxa. Additionally, we find no difference between sympatric and allopatric pairs in the rate of divergence in colour pattern, overall body shape, or functional morphological traits associated with locomotion or feeding. However, sympatric pairs show a significant decrease in the rate of divergence in all of these traits with increasing time since their divergence, suggesting an elevated rate of divergence at the time of speciation, the effect of which attenuates as divergence time increases. Our results are consistent with an important role for geographical overlap driving phenotypic divergence early in the speciation process, but the lack of difference in rates between sympatric and allopatric pairs indicates that the interactions between closely related species are not dominant drivers of this divergence.

Morphological and genetic divergence supports peripheral endemism and a recent evolutionary history of Chrysiptera demoiselles in the subtropical South Pacific

“…Nonetheless, similar to our findings, a recent study of haemulid fishes found that the level of divergence in phenotypic traits and colour of sister species, including those that occur in allopatry, was uncorrelated with time since divergence (Tavera and Wainwright 2019). Furthermore, studies focused on individuals within fish populations have suggested that morphological change and associated diet specialisation occurs at an early ecological and evolutionary stage of divergence, and before lineage diversification (Kusche et al 2014).…”

Widespread sympatry in a species-rich clade of marine fishes (Carangoidei)

“…Most comparable analyses of marine fishes have found a higher prevalence of allopatry between sister species, from 62% in New World haemulid fishes (N = 42 spp. ; Tavera and Wainwright 2019), to 64% in parrotfishes (N = 61 spp. ; Choat et al 2012), to 88% in Halichoeres wrasses (N = 24 spp.…”

“…Few studies have applied analyses of age-range correlation and range symmetry in large and taxonomically inclusive lineages of vertebrates, particularly marine fishes (Fitzpatrick and Turelli 2006; Phillimore et al 2008; Wollenberg et al 2011; Mora et al 2012; Anacker and Strauss 2014; Hodge and Bellwood 2015; Tavera and Wainwright 2019). The use of such approaches is hindered by lack of comprehensive taxon sampling and availability of range data for many species.…”

Overview on Karyotype Stasis in Atlantic Grunts (Eupercaria, Haemulidae) and the Evolutionary Extensions for Other Marine Fish Groups

“…Analysis of the extensive geographic distribution, with a marked spatial overlap of sibling species, has revealed that besides vicariant events, ecological speciation also participates in the evolutionary diversification of this family of fishes . In fact, in this family, recurrent sympatric speciation processes occurring in short periods of time (∼5 M.a), especially in species of the genus Haemulon, have been observed (Tavera et al, 2012;Tavera and Wainwright, 2019); recent events of genetic introgression have also been observed in some cases (Bernal et al, 2017). In ecological speciation processes, with the fragmentation of ecological niches, in general, the split of the gene pool occurs without remarkable genetic changes or high selection pressures (Rocha and Bowen, 2008), thereby producing less propitious conditions to fix conspicuous chromosome rearrangements.…”

“…Grunts are smallto-medium-sized carnivorous fishes that predominantly inhabit rocky substrates at a low depth (Nelson et al, 2016). This group has conservative karyotypes (Motta-Neto et al, 2012), a wellknown phylogenetic relationship Tavera et al, 2012), and several examples of sibling-species divergence in the New World (Tavera et al, 2018;Bernal et al, 2019;Tavera and Wainwright, 2019), making it a good model for the evaluation of slow chromosome changes in a space-temporal context.…”