Figure 1.
Geographic location and labels of the oceanic stations sampled during the cruises FORCLIM 7, AMT-5, C-MarZ, OISO-4, REVELLE, KT-06-11 and offshore Villefranche-sur-mer, San Diego and Bermuda. Dashed lines represent ship routes and black circles are collecting stations from where Globoconella inflata specimens have been genetically analyzed.
Table 1.
Location of the sampling stations, with indications of the number of sequenced and genotyped specimens of Globoconella inflata (in parenthesis, number of copies from the same individual).
Table 2.
Inter-individual patristic distances (substitutions per site) measured on phylogenetic trees obtained from the five datasets analyzed (see Methods for details about the co nstruction of the datasets).
Table 3.
Intra-individual patristic distances (substitutions per site) measured on phylogenetic trees obtained from four of the five analyzed datasets (no available distances for the CleITS dataset; see Methods for details about the construction of the datasets).
Figure 2.
Phylogenetic analysis of Globoconella inflata.
ITS-based evolutionary relationships between 135 clones of G. inflata from 41 localities in the world oceans (see Table 1 and Figure 1 for station names and locations). This Maximum Likelihood inference shows the relationships between the two phylotypes (Type I in red and Type II in blue). The bootstrap scores (500 replicates) greater than 80% are given next to branches for each dataset following a CleITS/CloITS/LarITS/ComITS-dataset order. The scale and branch lengths are given in % of nucleotide substitution per site. The colors associated to leaf labels indicate geographic area of collection: blue = subpolar Indian Ocean; light blue = subpolar South Atlantic; Pink = South Atlantic north of the Subpolar Front; Yellow = Indian Ocean north of the Subpolar Front; red = North Atlantic; green = South Pacific; Orange = North Pacific. Circles, stars and squares associated to specific colors indicate clones sequenced from the same individuals.
Figure 3.
Geographical and ecological distribution of genotypes.
Latitudinal distribution of Types I and II of Globoconella inflata in the South Hemisphere (the North Hemisphere contains representatives of Type I only). (A) Polar projection of the cruises AMT-5 (September-October 1997), OISO-4 (January–February 2000) and REVELLE (January–february 2004); the position of the Antarctic Circumpolar Current is shown in blue [61]. Temperature and fluorescence profiles (0–250 m) are given for the cruise OISO-4 (Bi and Bii) and AMT-5 (Ci and Cii); occurrences of genotypes (circles for Type I; diamonds for Type II) are given for each station, positioned with latitudes. Colors as in Figure 1.
Figure 4.
Morpho-species vs. genotype distributions.
The bubble biplot allows the direct comparison of the relative abundance of Globoconella inflata (proportional to filled circle size; empty circle: absent) in surface sediments of 1265 localities from the North (in red) and South (in blue) Hemisphere with the thermal structure of the 500 upper meters of the water column. A least square regression between the mean values of PC1 for each 1 SST-°C interval and SST (Sea Surface Temperature = 10 meters temperature following [3]; standard deviation indicated by a gray line) shows the good relationship between these two descriptors in the 0–25°C-SST interval and illustrates the clear thermal boundary (between 8 and 12°C based on the studied samples) between the two genotypes for the cruises AMT-5 and OISO-4 (colors and symbols as in Figure 2).
Figure 5.
Morphological differences between Globoconella inflata genotypes.
A. Log-Log Biplot of specimen major axis vs. aperture/terminal chamber length ratio for 306 specimens collected during the cruise AMT-5 in the South Atlantic. All specimens collected north of the Subpolar Front are considered to be representatives of Type I; all others are considered as Type II. The discriminant boundary that maximizes the separation between the two genotypes is represented by a gray dashed line. B. Histograms and Gaussian kernel densities of the log-ratio between the aperture/terminal chamber length ratio and the specimen major axis.