Contrasting patterns in species boundaries and evolution of anemonefishes (Amphiprioninae, Pomacentridae) in the centre of marine biodiversity

Abstract

Many species of coral reef fishes are distinguished by their colour patterns, but genetic studies have shown these are not always good predictors of genetic isolation and species boundaries. The genus Amphiprion comprises several species that have very similar colouration. Additionally, morphological characters are so variable, that sibling species can show a considerable overlap, making it difficult to differentiate them. In this study, we investigated the species boundaries between the sibling species pair A. ocellaris and A. percula (Subgenus Actinicola) and three closely related species of the subgenus Phalerebus (A. akallopisos, A. perideraion, A. sandaracinos) by phylogenetic analysis of mitochondrial cytochrome b and control region sequences. These two subgenera show strong differences in their patterns of species boundaries. Within the A. ocellaris/A. percula complex, five clades were found representing different geographic regions. Two major divergences both with genetic distances of 4-7% in cty b and 17-19% in the d-loop region indicate the presence of three instead of two deep evolutionary lineages. The species of the subgenus Phalerebus show three monophyletic clades, independent of the geographical location of origin, but concordant to the morphological species classification. The genetic distances between the Phalerebus species were 2-5% in cty b and 10-12% in the control region.

Phylogeography unplugged: comparative surveys in the genomic era

“…While evolutionary radiations can be inferred from temporal patterns of diversification (exemplified by "early bursts"), adaptive radiations are associated with ecological opportunity (Losos 2010), which is often revealed through selection on morphological traits. For example, color is a very important taxonomic character in many groups, and can indicate underlying genetic differentiation (e.g., Meyer et al 2005, Drew et al 2008, Timm et al 2008, Malay and Paulay 2009). However, coloration is not always a reliable taxonomic character; the brightly-colored pygmy angelfishes (Centropyge spp.)…”

Hybridisation and diversification in the adaptive radiation of clownfishes

“…One recent hybridisation event likely occurred around node 41 ( Figure 2) between A. percula and A. ocellaris. The distribution of those two species is mostly allopatric, but they share a common boundary and may overlap at some locations [26] possibly leading to gene exchange. Yet, despite similar behaviour and ecology, the species of the percula clade seemingly failed to radiate [19].…”

Genetic identification and phylogenetic relationships of Indian clariids based on mitochondrial COI sequences

“…Mitochondrial DNA has been extensively studied in fish phylogenetics since mitochondrial 16S rRNA gene and the protein coding cytochrome C Oxidase subunit I (COI) genes are highly conserved (Lakra et al, 2009). Mitochondrial DNA (mtDNA) has been generally employed in phylogenetic studies because it evolves much more rapidly than nuclear DNA, which will result in the accumulation of differences between closely related species (Timm et al, 2008). The present investigation is an attempt to estimate the phylogenetic relationships among clariid catfishes seen in India, i.e., C. dussumieri, C. magur, and C. gariepinus, and also to relate this phylogeny to the wider context of the genus worldwide which is very important from the point of view of their utilization in conservation and management plan of these commercially important species.…”