Brazeau et al. 2013

scientific article | PLoS ONE | open access Open access small aa108fa7f478951c693af64a05bc4b46e6711dbb69a20809512a129d4d6b870f

Genetic Structure in the Coral, Montastraea cavernosa: Assessing Genetic Differentiation among and within Mesophotic Reefs

Brazeau DA, Lesser MP, Slattery M

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Mesophotic coral reefs (30–150 m) have recently received increased attention as a potential source of larvae (e.g., the refugia hypothesis) to repopulate a select subset of the shallow water (<30 m) coral fauna. To test the refugia hypothesis we used highly polymorphic Amplified Fragment Length Polymorphism (AFLP) markers as a means to assess small-scale genetic heterogeneity between geographic locations and across depth clines in the Caribbean coral, Montastraea cavernosa. Zooxanthellae-free DNA extracts of coral samples (N = 105) were analyzed from four depths, shallow (3–10 m), medium (15–25 m), deep (30–50 m) and very deep (60–90 m) from Little Cayman Island (LCI), Lee Stocking Island (LSI), Bahamas and San Salvador (SS), Bahamas which range in distance from 170 to 1,600 km apart. Using AMOVA analysis there were significant differences in ΦST values in pair wise comparisons between LCI and LSI. Among depths at LCI, there was significant genetic differentiation between shallow and medium versus deep and very deep depths in contrast there were no significant differences in ΦST values among depths at LSI. The assignment program AFLPOP, however, correctly assigned 95.7% of the LCI and LSI samples to the depths from which they were collected, differentiating among populations as little as 10 to 20 m in depth from one another. Discriminant function analysis of the data showed significant differentiation among samples when categorized by collection site as well as collection depth. FST outlier analyses identified 2 loci under positive selection and 3 under balancing selection at LCI. At LSI 2 loci were identified, both showing balancing selection. This data shows that adult populations of M. cavernosa separated by depths of tens of meters exhibits significant genetic structure, indicative of low population connectivity among and within sites and are not supplying successful recruits to adjacent coral reefs less than 30 m in depth.

Research sites

10.1371   journal.pone.0065845
Depth range
3- 90 m

Mesophotic “mentions”
8 x (total of 5563 words)

Connectivity Community structure Molecular ecology

Research focus
Scleractinia (Hard Corals)

Cayman Islands Bahamas El Salvador

Research platforms
Diving - Technical Open-Circuit Diving - Technical Rebreather Manned Submersible
Author profiles
Daniel Brazeau ( 2 pubs)
Michael P. Lesser ( 14 pubs)
Marc Slattery ( 11 pubs)