title: Genetic data, reproduction season and reproductive strategy data support the existence of biological species in Ophioderma longicauda.
abstract: Cryptic species are numerous in the marine environment. The brittle star Ophioderma longicauda is composed of six mitochondrial lineages, encompassing brooders, which form a monophyletic group, and broadcasters, from which the brooders are derived. To clarify the species limits within O. longicauda, we compared the reproductive status of the sympatric lineages L1 and L3 (defined after sequencing a portion of the mitochondrial gene COI) during the month of May in Greece. In addition, we genotyped a nuclear marker, intron i51. Each L3 female was brooding, whereas all L1 specimens displayed full gonads, suggesting temporal pre-zygotic isolation between brooders and broadcasters. Statistical differences were found among lineages in morphology and bathymetric distribution. Finally, the intron i51 was polymorphic in L1 (60 individuals), but monomorphic in L3 (109 individuals), confirming the absence of gene flow between brooders and broadcasters. In conclusion, the broadcasting lineage L1 and the brooding lineage L3 are different biological species.
authors.affiliation: Aix-Marseille Université, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), CNRS - IRD - UAPV, station marine d'Endoume, chemin de la Batterie-des-Lions, 13007 Marseille, France. Electronic address: alexandra.weber@imbe.fr.
authors.forename: Alexandra Anh-Thu
authors.initials: AA
authors.lastname: Weber
authors.affiliation: Department of Zoology, Swedish Museum of Natural History, Box 50007, 10405 Stockholm, Sweden.
authors.forename: Sabine
authors.initials: S
authors.lastname: Stöhr
authors.affiliation: Aix-Marseille Université, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), CNRS - IRD - UAPV, station marine d'Endoume, chemin de la Batterie-des-Lions, 13007 Marseille, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Chenuil
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D004447:Echinodermata / Q000145:classification* / Q000235:genetics* / Q000502:physiology*; D005260:Female; D005306:Fertilization; D005602:France; D051456:Gene Flow; D005838:Genotype; D006066:Gonads / Q000033:anatomy & histology / Q000254:growth & development; D006115:Greece; D007438:Introns / Q000235:genetics; D008297:Male; D008522:Mediterranean Sea; D010802:Phylogeny; D012098:Reproduction; D012621:Seasons; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D004272:DNA, Mitochondrial
keywords: Brooding species; Cryptic species; Cytochrome oxidase subunit I; EPIC; Espèce incubante; Espèces cryptiques; Ophiuroidea; Sous-unité I de la cytochrome oxydase