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Abstract While the presence of morphologically cryptic species is increasingly recognized, we still lack a useful understanding of what causes and maintains co‐occurring cryptic species and its consequences for the ecology, evolution, and conservation of communities. We sampled 724Pocilloporacorals from five habitat zones (the fringing reef, back reef, and fore reef at 5, 10, and 20 m) at four sites around the island of Moorea, French Polynesia. Using validated genetic markers, we identified six sympatric species ofPocillopora, most of which cannot be reliably identified based on morphology:P. meandrina(42.9%),P. tuahiniensis(25.1%),P. verrucosa(12.2%),P. acuta(10.4%),P. grandis(7.73%), andP.cf.effusa(2.76%). For 423 colonies (58% of the genetically identified hosts), we also usedpsbAncror ITS2 markers to identify symbiont species (Symbiodiniaceae). The relative abundance ofPocilloporaspecies differed across habitats within the reef. Sister taxaP. verrucosaandP. tuahiniensishad similar niche breadths and hosted the same specialist symbiont species (mostlyCladocopium pacificum) but the former was more common in the back reef and the latter more common deeper on the fore reef. In contrast, sister taxaP. meandrinaandP. grandishad the highest niche breadths and overlaps and tended to host the same specialist symbiont species (mostlyC. latusorum).Pocillopora acutahad the narrowest niche breadth and hosted the generalist, and more thermally tolerant,Durusdinium gynnii. Overall, there was a positive correlation between reef habitat niche breadth and symbiont niche breadth—Pocilloporaspecies with a broader habitat niche also had a broader symbiont niche. Our results show how fine‐scale variation within reefs plays an important role in the generation and coexistence of cryptic species. The results also have important implications for how niche differences affect community resilience, and for the success of coral restoration practices, in ways not previously appreciated.
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Pocillopora tuahiniensis: a new species of scleractinian coral (Scleractinia, Pocilloporidae) from French Polynesia
Pocillopora tuahiniensis sp. nov. is described based on mitochondrial and nuclear genomic data, algal symbiont genetic data, geographic isolation, and its distribution pattern within reefs that is distinct from other sympatric Pocillopora species (Johnston et al. 2022a, b). Mitochondrial and nuclear genomic data reveal that P. tuahiniensis sp. nov. is a unique species, sister to P. verrucosa, and in a clade different from that of P. meandrina (Johnston et al. 2022a). However, the gross in situ colony appearance of P. tuahiniensis sp. nov. cannot easily be differentiated from that of P. verrucosa or P. meandrina at Mo’orea. By sequencing the mtORF region, P. tuahiniensis sp. nov. can be easily distinguished from other Pocillopora species. Pocillopora tuahiniensis sp. nov. has so far been sampled in French Polynesia, Ducie Island, and Rapa Nui (Armstrong et al. 2023; Edmunds et al. 2016; Forsman et al. 2013; Gélin et al. 2017; Mayfield et al. 2015; Oury et al. 2021; Voolstra et al. 2023). On the fore reefs of Mo’orea, P. tuahiniensis sp. nov. is very abundant ≥10 m and is one of the most common Pocillopora species at these depths (Johnston et al. 2022b). It can also be found at a much lower abundance at shallow depths on the fore reef and back reef lagoon. The holotype is deposited at the Smithsonian Institution as USNM-SI 1522390 and the mtORF Genbank accession number is OP418359.
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- PAR ID:
- 10509051
- Publisher / Repository:
- https://mcr.lternet.edu/bibliography
- Date Published:
- Journal Name:
- Zootaxa
- Volume:
- 5369
- Issue:
- 1
- ISSN:
- 1175-5326
- Page Range / eLocation ID:
- 117 to 124
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.11646/zootaxa.5369.1.5
