Phylogenetic relationships among the clownfish-hosting sea anemones

Abstract

32The clownfish-sea anemone symbiosis has been a model system for understanding fundamental 33 evolutionary and ecological processes. However, our evolutionary understanding of this 34 symbiosis comes entirely from studies of clownfishes. A holistic understanding of a model 35 mutualism requires systematic, biogeographic, and phylogenetic insight into both partners. Here, 36we conduct the largest phylogenetic analysis of sea anemones (Order Actiniaria) to date, with a 37 focus on expanding the biogeographic and taxonomic sampling of the 10 nominal clownfish-38 hosting species. Using a combination of mtDNA and nuDNA loci we test 1) the monophyly of 39 each clownfish-hosting family and genus, 2) the current anemone taxonomy that suggests 40 symbioses with clownfishes evolved multiple times within Actiniaria, and 3) whether, like the 41 clownfishes, there is evidence that host anemones have a Coral Triangle biogeographic origin. 42Our phylogenetic reconstruction demonstrates widespread poly-and para-phyly at the family and 43 genus level, particularly within the family Stichodactylidae and genus Sticodactyla, and suggests 44 that symbioses with clownfishes evolved minimally three times within sea anemones. We further 45 recover evidence for a Tethyan biogeographic origin for some clades. Our data provide the first 46 evidence that clownfish and some sea anemone hosts have different biogeographic origins, and 47 that there may be cryptic species of host anemones. Finally, our findings reflect the need for a 48 major taxonomic revision of the clownfish-hosting sea anemones. 49 50 488 (Live Aquaria) and Laura Simmons (Cairns Marine) provided anemone samples from Tonga and 489

Variation on a theme: pigmentation variants and mutants of anemonefish

“…Recent phylogenetic analyses of Amphiprioninae with molecular clock analyses show that a large majority of anemonefish species have also evolved within the last 5 Myr, likely due to biogeography combined with ecological speciation related to host-anemone associations [30,32]. This Amphiprioninae phylogenetic framework combined with recent phylogenetic data on anemones [62] and the analyses of coloration and patterning as suggested in this review promise to open exciting new avenues of research that will allow a better understanding of the evolution of anemonefish pigmentation diversity.…”

Phylogenomics reveals coincident divergence between giant host sea anemones and the clownfish adaptive radiation

“…We assembled a phylogenomic dataset for sea anemones that included representative samples from the 10 clownfish-hosting species (Table S1), which have recently undergone a major nomenclatural revision [5]. Because the clownfish-hosting species have been previously recovered to belong to three clades that are hypothesized to have evolved symbiosis with clownfishes independently [4,5], we included >50 species of sea anemones across Order Actiniaria to re-evaluate this hypothesis using genomic data (Table S1). Genomic DNA from newly collected samples was extracted, quantified, and prepared for sequencing using baitcapture probes for Class Anthozoa targeting ultra-conserved element (UCE) and exon loci [6].…”

“…The mutualism between clownfishes (or anemonefishes) and their giant host sea anemones are among the most immediately recognizable animal interactions on the planet and have attracted a great deal of popular and scientific attention [1-5]. However, our evolutionary understanding of this iconic symbiosis comes almost entirely from studies on clownfishes-a charismatic group of 28 described species in the genus Amphiprion Far from being mere habitat space, the host sea anemones also receive substantial benefits from hosting clownfishes, making the mutualistic and co-dependent nature of the symbiosis well established [4,5]. Yet the evolutionary consequences of mutualism with clownfishes have remained a mystery from the host perspective.…”

“…The mutualism between clownfishes (or anemonefishes) and their giant host sea anemones are among the most immediately recognizable animal interactions on the planet and have attracted a great deal of popular and scientific attention [1][2][3][4][5]. However, our evolutionary understanding of this iconic symbiosis comes almost entirely from studies on clownfishes-a charismatic group of 28 described species in the genus Amphiprion [2].…”

“…Far from being mere habitat space, the host sea anemones also receive substantial benefits from hosting clownfishes, making the mutualistic and co-dependent nature of the symbiosis well established [4,5]. Yet the evolutionary consequences of mutualism with clownfishes have remained a mystery from the host perspective.…”