title: Genetic spatial structure of an anchialine cave annelid indicates connectivity within - but not between - islands of the Great Bahama Bank.
abstract: Land-locked anchialine blue holes are karstic sinkholes and caves with tidally influenced, vertically stratified water bodies that harbor endemic fauna exhibiting variable troglomorphic features. These habitats represent island-like systems, which can serve to elucidate evolutionary and biogeographic processes at local scales. We investigated whether the 'continuous spelean corridor' hypothesis may elucidate the biogeographical distributions of the stygobitic annelid Pelagomacellicephala iliffei (Polynoidae) collected from the Great Bahama and Caicos Banks of the Bahamas Archipelago. Phylogenetic reconstructions were performed using Bayesian Inference on individual and combined datasets of three molecular markers (16S rDNA, COI, 18S rDNA) and species delimitation employed three widely accepted methods in DNA taxonomy, namely GMYC, bPTP, and ABGD. Mantel tests were used to test the effect of geography on genetic structure. Using these analyses, we recovered five independently evolving entities of the focal species across four islands of the Great Bahama Bank including Cat, Eleuthera, Exumas, and Long. Genetic data yielded strong correlations between islands and phylogenetic entities, signifying independent evolutionary histories within anchialine caves across the platform. The island of Eleuthera showed intra-island gene flow and dispersal capabilities between blue holes separated by 115km, providing evidence of a crevicular spelean corridor within the island. However, no evidence of inter-island dispersal is present in the analyzed system. Consistent with previous biogeographic studies of cave crustaceans, the major barriers shaping the cave biota of the Bahamas Archipelago appears to be the deep trenches and channels separating the Bahamian banks.
authors.affiliation: University of Copenhagen, Marine Biological Section, Department of Biology, Universitetsparken 4, 1st floor, 2100 Copenhagen Ø, Denmark. Electronic address: brett.gonzalez@bio.ku.dk.
authors.forename: Brett C
authors.initials: BC
authors.lastname: Gonzalez
authors.affiliation: University of Copenhagen, Marine Biological Section, Department of Biology, Universitetsparken 4, 1st floor, 2100 Copenhagen Ø, Denmark; Consiglio Nazionale delle Ricerche, Istituto per lo Studio degli Ecosistemi CNR-ISE, Largo Tonolli 50, 28922 Verbania Pallanza, Italy. Electronic address: amartinez.ull@gmail.com.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Martínez
authors.affiliation: Texas A&M University at Galveston, Department of Marine Biology, 1001 Texas Clipper Road, Galveston, TX 77553, USA. Electronic address: bordae@tamug.edu.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Borda
authors.affiliation: Texas A&M University at Galveston, Department of Marine Biology, 1001 Texas Clipper Road, Galveston, TX 77553, USA. Electronic address: iliffet@tamug.edu.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Iliffe
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto per lo Studio degli Ecosistemi CNR-ISE, Largo Tonolli 50, 28922 Verbania Pallanza, Italy. Electronic address: d.fontaneto@ise.cnr.it.
authors.forename: Diego
authors.initials: D
authors.lastname: Fontaneto
authors.affiliation: University of Copenhagen, Marine Biological Section, Department of Biology, Universitetsparken 4, 1st floor, 2100 Copenhagen Ø, Denmark. Electronic address: kworsaae@bio.ku.dk.
authors.forename: Katrine
authors.initials: K
authors.lastname: Worsaae
mesh_terms: D000818:Animals; D000845:Annelida / Q000145:classification* / Q000235:genetics; D001444:Bahamas; D001499:Bayes Theorem; D005075:Biological Evolution; D059552:Caves; D017753:Ecosystem; D051456:Gene Flow; D014644:Genetic Variation; D005843:Geography; D062312:Islands; D010802:Phylogeny; D058974:Phylogeography
keywords: Anchialine; DNA taxonomy; Ecological speciation; Pelagomacellicephala iliffei; Polynoidae; Species delineation