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Title: Cophylogeny and specificity between cryptic coral species ( Pocillopora spp.) at Mo′orea and their symbionts (Symbiodiniaceae)
Abstract

The congruence between phylogenies of tightly associated groups of organisms (cophylogeny) reflects evolutionary links between ecologically important interactions. However, despite being a classic example of an obligate symbiosis, tests of cophylogeny between scleractinian corals and their photosynthetic algal symbionts have been hampered in the past because both corals and algae contain genetically unresolved and morphologically cryptic species. Here, we studied co‐occurring, crypticPocilloporaspecies from Mo′orea, French Polynesia, that differ in their relative abundance across depth. We constructed new phylogenies of the hostPocillopora(using complete mitochondrial genomes, genomic loci, and thousands of single nucleotide polymorphisms) and their Symbiodiniaceae symbionts (using ITS2 and psbAncrmarkers) and tested for cophylogeny. The analysis supported the presence of fivePocilloporaspecies on the fore reef at Mo′orea that mostly hosted eitherCladocopium latusorumorC. pacificum.OnlyPocilloporaspecies hostingC. latusorumalso hosted taxa fromSymbiodiniumandDurusdinium. In general, theCladocopiumphylogeny mirrored thePocilloporaphylogeny. WithinCladocopiumspecies, lineages also differed in their associations withPocilloporahaplotypes, except those showing evidence of nuclear introgression, and with depth in the two most commonPocilloporaspecies. We also found evidence for a newPocilloporaspecies (haplotype 10), that has so far only been sampled from French Polynesia, that warrants formal identification. The linked phylogenies of thesePocilloporaandCladocopiumspecies and lineages suggest that symbiont speciation is driven by niche diversification in the host, but there is still evidence for symbiont flexibility in some cases.

 
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Award ID(s):
2224354 1829867
NSF-PAR ID:
10373439
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Molecular Ecology
Volume:
31
Issue:
20
ISSN:
0962-1083
Page Range / eLocation ID:
p. 5368-5385
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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