Marine Biology Research ISSN: 1745-1000 (Print) 1745-1019 (Online) Journal homepage: http://www.tandfonline.com/loi/smar20 Phylogeography of the marbled crab Pachygrapsus marmoratus (Decapoda, Grapsidae) along part of the African Mediterranean coast reveals genetic homogeneity across the Siculo-Tunisian Strait versus heterogeneity across the Gibraltar Strait Temim Deli, Sara Fratini, Lapo Ragionieri, Khaled Said, Noureddine Chatti & Christoph D. Schubart To cite this article: Temim Deli, Sara Fratini, Lapo Ragionieri, Khaled Said, Noureddine Chatti & Christoph D. Schubart (2016) Phylogeography of the marbled crab Pachygrapsus marmoratus (Decapoda, Grapsidae) along part of the African Mediterranean coast reveals genetic homogeneity across the Siculo-Tunisian Strait versus heterogeneity across the Gibraltar Strait, Marine Biology Research, 12:5, 471-487, DOI: 10.1080/17451000.2016.1154972 To link to this article: http://dx.doi.org/10.1080/17451000.2016.1154972 Published online: 27 May 2016. Submit your article to this journal Article views: 47 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=smar20 Download by: [Dr Temim Deli] Date: 25 June 2016, At: 08:04 MARINE BIOLOGY RESEARCH, 2016 VOL. 12, NO. 5, 471–487 http://dx.doi.org/10.1080/17451000.2016.1154972 ORIGINAL ARTICLE Phylogeography of the marbled crab Pachygrapsus marmoratus (Decapoda, Grapsidae) along part of the African Mediterranean coast reveals genetic homogeneity across the Siculo-Tunisian Strait versus heterogeneity across the Gibraltar Strait Temim Delia, Sara Fratinib, Lapo Ragionierib,c, Khaled Saida, Noureddine Chattia and Christoph D. Schubartd aLaboratory of Genetics, Biodiversity and Enhancement of Bioresources, University of Monastir, Higher Institute of Biotechnology of Monastir, Monastir, Tunisia; bDepartment of Biology, University of Florence, Sesto Fiorentino, Italy; cInstitute for Zoology, Functional Peptidomics, University of Cologne, Cologne, Germany; dFaculty of Biology, Zoology and Evolution, University of Regensburg, Regensburg, Germany ABSTRACT ARTICLE HISTORY We investigate the influence of previously postulated biogeographic barriers in the Received 30 August 2015 Mediterranean Sea on the population genetic structure of a highly dispersive and Accepted 11 February 2016 continuously distributed coastal species. In particular, we examine nuclear and mitochondrial Published online 27 May genetic variation in the marbled crab, Pachygrapsus marmoratus, across part of the African 2016 fl Mediterranean coast in order to assess the in uence of the Siculo-Tunisian Strait on its RESPONSIBLE EDITOR population genetic structure. Four polymorphic microsatellite loci were genotyped for 110 Gavin Gouws individuals, collected from eight locations covering parts of the Algerian, Tunisian and Libyan coasts. In addition, mtDNA corresponding to the Cox1 gene was sequenced for 80 samples. KEYWORDS The corresponding results show contrasting patterns of genetic differentiation. While mtDNA Biogeographic breaks; results revealed a homogeneous haplotype composition in our study area, microsatellite data connectivity; gene flow; depicted genetic differentiation among populations, but not associated with any geographic genetic patchiness; larval barrier. This pattern, already recorded for this species from different geographic regions, may dispersal; population genetics hint at the involvement of a complex series of abiotic and biotic factors in determining genetic structure. Demographic history reconstruction, inferred from mtDNA data, supports demographic and spatial expansion for the North African metapopulation dating back to the Mid-Pleistocene and following an historical bottleneck. Comparison of these African mitochondrial sequences with new sequences from a Turkish population and previously published sequences revealed a weak but significant separation of Atlantic and Mediterranean populations across the Gibraltar Strait, which was not recorded in previous studies of this grapsid species. The transition zone between the Eastern and Introduction Western Mediterranean Basins constitutes one of the Downloaded by [Dr Temim Deli] at 08:04 25 June 2016 The Mediterranean Sea is characterized by a complex best documented biogeographic transitions in the circulation system in which two main water bodies Mediterranean Sea (see Arnaud-Haond et al. 2007). meet, namely the Modified Atlantic Water (MAW) and The Siculo-Tunisian Strait, located between Cap Bon the Levantine Intermediate Water (LIW) (Astraldi et al. in Tunisia and Mazara Del Vallo in Sicily (Italy), is postu- 1999). The hydrology is also shaped by the presence lated to separate these two Mediterranean basins of physical barriers such as straits and channels (Béran- (Quignard 1978). On both sides of this barrier, water ger et al. 2004). The most important Mediterranean bar- bodies circulate with different hydrological, physical riers are the Almeria-Oran Oceanographic Front, the and chemical characteristics (Béranger et al. 2004). It Siculo-Tunisian Strait and the hydrographic isolation of has been documented as a geographic break, causing the Aegean-Ionian and Adriatic Seas (Astraldi et al. population genetic differentiation in several marine 1999;Patarnelloetal.2007). These barriers are known species (e.g. Quesada et al. 1995; Borsa et al. 1997; to restrict gene flow in some species, leading to Bahri-Sfar et al. 2000; Nikula & Vainola 2003; Arnaud- genetic differentiation among populations (Borsa et al. Haond et al. 2007; Mejri et al. 2009; Zitari-Chatti et al. 1997;Patarnelloetal.2007). 2009; Kaouèche et al. 2011; Ragionieri & Schubart CONTACT Temim Deli [email protected] Laboratory of Genetics, Biodiversity and Enhancement of Bioresources (LR11ES41), University of Monastir, Higher Institute of Biotechnology of Monastir, Av. Tahar Hadded, B.P. 74, Monastir 5000, Tunisia © 2016 Informa UK Limited, trading as Taylor & Francis Group 472 T. DELI ET AL. 2013). Therefore, population genetic analyses across patterns of genetic differentiation among geographi- this potential barrier may contribute to the identifi- cally close populations from the coast of Tuscany cation of the phylogeographic patterns and to depict (Fratini et al. 2008, 2011) and the Tuscan archipelago historical events that might have shaped the genetic (Fratini et al. 2013), with a genetic separation structure of marine species. between the Ligurian and Tyrrhenian Seas populations. The African Mediterranean coast, especially the part Another micro-geographic survey along the Portu- encompassing the Tunisian and Libyan littoral, is con- guese coast, using the same nuclear markers, revealed sidered as an appropriate area to study biogeographic the existence of genetic patchiness among populations processes because it harbours populations located of P. marmoratus, unrelated to any geographic gradient west and east of the well-known biogeographic (Silva et al. 2009b). No genetic structure was found at a barrier of the Siculo-Tunisian Strait. Furthermore, it is micro-geographic scale along the Tunisian coast under hypothesized that episodes of oceanic fluctuation the likely influence of the Siculo-Tunisian Strait, but this experienced within the central Mediterranean, specifi- study was based only on restricted fragment length cally across the transition zone of the Siculo-Tunisian polymorphisms (RFLPs) analyses of the mitochondrial Strait, during the Pleistocene, may have affected both cytochrome oxidase I (Cox1) gene (Deli et al. 2015a). the genetic and demographic structure of populations The use of more variable markers, such as nuclear for a broad variety of marine taxa (Bahri-Sfar et al. 2000; microsatellites, may allow for the detection of subtle Stefanni & Thorley 2003; Zardoya et al. 2004; Mejri et al. population structure along the African Mediterranean 2009; Zitari-Chatti et al. 2009; Kaouèche et al. 2011). coast, as these polymorphic markers provided high The marbled crab Pachygrapsus marmoratus (Fabri- genetic resolution in P. marmoratus over small geo- cius, 1787) is one of the most widely distributed and graphic scales (see Fratini et al. 2008, 2011, 2013; abundant decapod crustacean species in the Mediter- Silva et al. 2009b). ranean and northeastern Atlantic rocky intertidal In light of these considerations, the main aim of the environment, and colonizes the whole intertidal belt present study was to re-investigate the influence of the regardless of its width (Cannici et al. 1999). Despite Siculo-Tunisian Strait on the genetic structure of popu- its high dispersal capacity, this grapsid species rep- lations of P. marmoratus along the African Mediterra- resents a good model to test for population subdivi- nean coast with molecular markers having higher sion, because of its local abundance and the resolution than those previously used by Deli et al. accumulated knowledge of its development, ecology (2015a). For this purpose, a set of polymorphic microsa- and genetics (Cannicci et al. 1999, 2002; Cuesta & Rodrí- tellite loci, specifically isolated and characterized for guez 2000; Ingle & Clark 2006; Fratini et al. 2008, 2011, this grapsid species by Fratini et al. (2006), were geno- 2013; Silva & Paula 2008; Ferreira Silva et al. 2009; Silva typed in samples from eight locations covering parts of et al. 2009a, 2009b). Factors expected to promote the Algerian, Tunisian and Libyan coasts. genetic homogeneity in this species include