Cryptic habitats and cryptic diversity: unexpected patterns of connectivity and phylogeographical breaks in a Mediterranean endemic marine cave mysid. Issue 11 (June 2014)

• Record Type: Journal Article
• Authors: Rastorgueff, Pierre‐Alexandre; Chevaldonné, Pierre; Arslan, Defne; Verna, Caroline; Lejeusne, Christophe
• Is Part Of: Molecular ecology. Volume 23:Issue 11(2014)
• Page Start: 2825
• Page End: 2843
• Publication Date: 2014-06
• Subjects: Molecular ecology -- Periodicals; Molecular population biology -- Periodicals; 576
• DOI: 10.1111/mec.12776
• Languages: English
• ISSNs: 0962-1083

Abstract

<abstract abstract-type="main" id="mec12776-abs-0001"> <title>Abstract</title> <p>The marine cave‐dwelling mysid <italic>Hemimysis margalefi</italic> is distributed over the whole Mediterranean Sea, which contrasts with the poor dispersal capabilities of this brooding species. In addition, underwater marine caves are a highly fragmented habitat which further promotes strong genetic structuring, therefore providing highly informative data on the levels of marine population connectivity across biogeographical regions. This study investigates how habitat and geography have shaped the connectivity network of this poor disperser over the entire Mediterranean Sea through the use of several mitochondrial and nuclear markers. Five deeply divergent lineages were observed among <italic>H. margalefi</italic> populations resulting from deep phylogeographical breaks, some dating back to the Oligo‐Miocene. Whether looking at the intralineage or interlineage levels, <italic>H. margalefi</italic> populations present a high genetic diversity and population structuring. This study suggests that the five distinct lineages observed in <italic>H. margalefi</italic> actually correspond to as many separate cryptic taxa. The nominal species, <italic>H. margalefi sensu stricto</italic>, corresponds to the westernmost lineage here surveyed from the Alboran Sea to southeastern Italy. Typical genetic breaks such as the Almeria‐Oran Front or the Siculo‐Tunisian Strait do not appear to be influential on the studied loci in <italic>H. margalefi sensu stricto</italic>. Instead, population structuring appears more complex and subtle than usually found for model species with a pelagic dispersal phase. The remaining four cryptic taxa are all found in the eastern basin, but incomplete lineage sorting is suspected and speciation might still be in process. Present‐day population structure of the different <italic>H. margalefi</italic> cryptic species appears to result from past vicariance events started in the Oligo‐Miocene and maintained by present‐day coastal topography, water circulation and habitat fragmentation.</p> </abstract>