title: Cryptic species diversity in sub-Antarctic islands: A case study of Lepidonotothen.
abstract: The marine fauna of the Southern Ocean is well known for an impressive adaptive radiation of fishes, the notothenioids. However, when compared to other marine areas, the frigid waters of the Southern Ocean also contain a seemingly large proportion of cryptic species. The documented instances of speciation in the absence of morphological change are largely observed in invertebrate taxa, in particular around peri- and sub-Antarctic islands such as South Georgia, which has been dubbed a cryptic species hotspot. This prevalence of cryptic species raises the question of how generalizable these patterns are for Antarctic vertebrates. Here we examine aspects of genotype and phenotype in an Antarctic notothenioid fish species, Lepidonotothen nudifrons, which is distributed in near shore habitats of the Antarctic Peninsula, South Orkney Islands, South Georgia, and the South Sandwich Islands. The results of our analyses show that L. nudifrons comprises two species. We highlight that cryptic species are phenomena not restricted to invertebrate lineages, raising the possibility that the species diversity of notothenioids and other Southern Ocean fishes is under-described. In addition, our findings raise several questions about the evolutionary origin and maintenance of morphological stasis in one of the most extreme habitats on earth.
authors.affiliation: North Carolina Museum of Natural Sciences, Raleigh, NC 27601, USA. Electronic address: alex.dornburg@naturalsciences.org.
authors.forename: Alex
authors.initials: A
authors.lastname: Dornburg
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Federman
authors.affiliation: Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA.
authors.forename: Ron I
authors.initials: RI
authors.lastname: Eytan
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA; Peabody Museum of Natural History, Yale University, New Haven, CT 06520, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Near
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D044822:Biodiversity; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000145:classification / Q000378:metabolism; D016002:Discriminant Analysis; D017753:Ecosystem; D019143:Evolution, Molecular; D006239:Haplotypes; D018398:Homeodomain Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000145:classification / Q000235:genetics / Q000378:metabolism; D010473:Perciformes / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D025341:Principal Component Analysis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D018398:Homeodomain Proteins; D004247:DNA; D009245:NADH Dehydrogenase
keywords: Antarctica; Notothenioidei; Southern Ocean; Species-delimitation; bGMYC