By author > Asami Takahiro

Thursday 3
Sessions générales
Session de posters
› 15:15 - 15:20 (05min)
Longitudinal differentiation among planktic foraminiferal populations in the Indo-Pacific Warm Pool
Yurika Ujiié  1@  , Thibault De Garidel-Thoron  2@  , Takahiro Asami  3  , Colomban De Vargas  4  
1 : Center for Advanced Marine Core Research
Kochi University
Monobe B200, Nankoku, Kochi 783-8502 -  Japon
2 : Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement  (CEREGE)  -  Website
Aix-Marseille Univ, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, CNRS, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, IRD, CEREGE, UMR 161, 13545 Aix en Provence cedex 4, France, Collège de France, CEREGE, 13545 Aix en Provence cedex 4, France
Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France -  France
3 : Department of Biology
Shinshu University
Matsumoto 390-8621 -  Japon
4 : Station Biologique de Roscoff  (SBR)
Universitie Pierre et Marie Curie (Paris 06) et CNRS
Place G. Teissier, BP 74, 29682 Roscoff cedex, France -  France

Evolutionary processes of pelagic planktons would have largely been dependent on the oceanic circulation system, which transports them between populations inhabiting water masses in sea-surface. Particularly, gene flow by oceanic currents flowing in the longitudinal direction may efficiently impede genetic differentiation of pelagic populations without confounding effects of climate. However, it has poorly been understood how responsible oceanic currents are for geographic distribution and evolution of pelagic plankton. We examined the phylogeography of a planktic foraminifer Pulleniatina obliquiloculata in the Indo-Pacific Warm Pool (IPWP) area by using partial small subunit ribosomal DNA (SSU rDNA) sequences. Three novel genetic types constituted different population structure among water masses. We found longitudinal clines in frequencies of these types within a narrow latitudinal range in the IPWP area. Populations inhabiting longitudinally distant water masses at the Pacific and Indian sides of the IPWP were genetically differentiated. Their divergence time suggests that these clines have been established according to development of the modern IPWP system. The present results exemplify that populations of a pelagic micro-plankton has been genetically differentiated within a single climate zone and suggest that changes of the oceanic circulation system impact on the geographic patterns of migration and divergence in pelagic organisms.

Online user: 1