Global scale same-specimen morpho-genetic analysis of Truncorotalia truncatulinoides: a perspective on the morphological species concept in planktonic foraminifera

• Published in: Palaeogeography, Palaeoclimatology, Palaeoecology
• Main Authors: Quillevere, Frederic, Morard, Raphaël, Escarguel, Gilles, Douady, Christophe Jean, Ujiie, Y, de Garidel-Thoron, Thibault, de Vargas, Colomban
• Other Authors: Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Shinshu Univ, Bio-Indic. & Traceurs, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-06-JCJC-0142,PALEO-CTD,PALeo-Hydroloy : Exploiting Oceanic Cryptic Taxonomic Diversity of planktonic foraminifera(2006)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: Planktonic foraminifera; biogeography; ribosomal DNA; morphometrics; species concept; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; Indian; Pacific; Southern Ocean
• Online Access: https://hal.science/hal-00911466; https://doi.org/10.1016/j.palaeo.2011.03.013

International audience Genetic analyses of planktonic foraminifera have unveiled significant levels of cryptic diversity, thus calling into question the usefulness of the morphological species concept for paleoceanographic reconstructions. Here, we present single-specimen combined genetic and morphological analyses performed on living Truncorotalia truncatulinoides collected across the world oceans. A combined morphogenetic analysis allows us to (1) detect five different genetic types (Types I to V) within the morphospecies T. truncatulinoides, (2) statistically analyze shape variations among these genotypes, and (3) assess the biogeographic patterns and the links between surface ocean properties and the distribution of morphological and genetic diversity within T. truncatulinoides. Of the five genetic types, Type I appears to inhabit the warm (sub)tropical waters of the South Hemisphere, Types II and V are found in the warm (sub)tropical waters of the Atlantic and NW Pacific, respectively, and Types III and IV appear to be restricted to the productive subtropical and the cold subpolar frontal zones of the Southern Ocean, respectively. Same-specimen morphogenetic comparisons reveal significant differences in test morphology between the warm (sub)tropical cluster of genotypes (Types I, II, and V) and the colder subpolar cluster of genotypes (Types III and IV). These results indicate that changes in shell conicalness, observed across the subtropical fronts in the Southern Ocean and for a long time interpreted as ecophenotypic variation, reflect genetic differentiation, with large, highly conical left (Indian Ocean) or right-coiled (Pacific Ocean) specimens north of the North Subtropical Front representing genetic Type I, and small, axially compressed and biconvex left-coiled specimens south of this front representing genetic Types III and IV. Our morphogenetic data are consistent with the scenario of a late Pleistocene invasion of the Southern Ocean by newly evolved T. truncatulinoides genotypes, specifically ...