A population genomics insight by 2b‐RAD reveals populations' uniqueness along the Italian coastline in Leptopsammia pruvoti (Scleractinia, Dendrophylliidae)

Elisa Boscari,Francesco Mastrototaro,Federica Costantini,Marco Abbiati,Simonetta Fraschetti,Ilaria A M Marino,Massimo Ponti,Leonardo Congiu,Marta Paterno,Lorenzo Zane,Angelo Cau,Chiara Papetti,Giorgio Bavestrello,Lisandro Benedetti‐Cecchi,Fabio Badalamenti,Giovanni Chimienti,Carlo Cerrano,Gianmarco Ingrosso,Rita Cannas

doi:10.1111/ddi.12918

Abstract

AbstractAimMarine bioconstructions such as coralligenous formations are hotspot of biodiversity and play a relevant ecological role in the preservation of biodiversity by providing carbon regulation, protection and nursery areas for several marine species. For this reason, the European Union Habitat Directive included them among priority habitats to be preserved. Although their ecological role is well established, connectivity patterns are still poorly investigated, representing a limit in conservation planning. The present study pioneers a novel approach for the analysis of connectivity in marine bioconstructor species, which often lack suitable genetic markers, by taking advantage of next‐generation sequencing techniques. We assess the geographical patterns of genomic variation of the sunset cup coral Leptopsammia pruvoti Lacaze‐Duthiers, 1897, an ahermatypic, non‐zooxanthellate and solitary scleractinian coral species common in coralligenous habitats and distributed across the Mediterranean Sea.LocationThe Italian coastline (Western and Central Mediterranean).MethodsWe applied the restriction site‐associated 2b‐RAD approach to genotype over 1,000 high‐quality and filtered single nucleotide polymorphisms in 10 population samples.ResultsThe results revealed the existence of a strongly supported genetic structure, with highly significant pairwise FST values between all the population samples, including those collected about 5 km apart from each other. Moreover, genomic data indicate that the strongest barriers to gene flow are between the western (Ligurian–Tyrrhenian Sea) and the eastern side (Adriatic Sea) of the Italian peninsula.Main conclusionsThe strong differentiation found in L. pruvoti is similar to that found in other species of marine bioconstructors investigated in this area, but it strongly contrasts with the small differences found in many fish and invertebrates at the same geographical scale. All in one, our results highlight the importance of assessing connectivity in species belonging to coralligenous habitats as, due to their limited dispersal ability, they might require specific spatial conservation measures.

Highlights

Marine conservation strategies are nowadays widely recognized to require a holistic approach that implies the shifting from the conser‐ vation of single species to that of entire ecosystems and their func‐ tions (Long, Charles, & Stephenson, 2015)
For the European marine realm, this ambitious goal is well interpreted by the Marine Strategy Framework Directive (MSFD; 2008/56/ EC; European Commission, 2008), which emphasizes the need of maintaining biological diversity ensuring a Good Environmental Status (GES)
This high level of genetic differentiation is fully consistent with the results of Discriminant Analysis of Principal Components (DAPC) (Figures 2 and 3), and with the high level of self‐ assignment detected by assignment tests (Table 4), which showed that from 80.8% up to 100% of individuals were consistent with a local origin

Summary

Introduction

Marine conservation strategies are nowadays widely recognized to require a holistic approach that implies the shifting from the conser‐ vation of single species to that of entire ecosystems and their func‐ tions (Long, Charles, & Stephenson, 2015). For the European marine realm, this ambitious goal is well interpreted by the Marine Strategy Framework Directive (MSFD; 2008/56/ EC; European Commission, 2008), which emphasizes the need of maintaining biological diversity ensuring a Good Environmental Status (GES). The establishment of opportunely selected marine protected areas (MPAs) represents one of the most effective approaches for marine biodiversity conservation (Gaines, White, Carr, & Palumbi, 2010; Micheli & Halpern, 2005; Pascual, Rives, Schunter, & Macpherson, 2017). The establishment of interconnected MPAs improves and extends the positive effects of assuring the persistence of a good state for bio‐ diversity (Boero et al, 2016; Gaines et al, 2010; Palumbi, 2004), providing the important spatial links needed to maintain large‐ scale ecosystem processes. Ensuring connectivity is crucial to improve resilience following environ‐ mental perturbations, failures in management or other hazards, and helping to ensure better long‐term sustainability of species (Cowen & Sponaugle, 2009)

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Conclusion