FIG. 5.

Minimum evolution phylogenetic tree of eukaryotic 18S rRNA gene sequences showing the positions of alveolate sequences. The tree was constructed with maximum likelihood criteria by using a GTR+I+G DNA substitution model with the variable-site gamma distribution shape parameter (G) at 0.5647, the proportion of invariable sites (I) at 0.0734, and the base frequencies and rate matrix for the substitution model suggested by Modeltest (59), based on 1,005 unambiguously aligned positions. Distance bootstrap values greater than 50% from an analysis of 1,000 bootstrap replicates are indicated at the nodes. Sequences recovered from the Framvaren Fjord are in bold. The numbers in triangles indicate the numbers of FV library sequences identified in taxonomic units. The numbers in parentheses indicate the primer sets (Table 1), and the colors indicate the three different libraries, as follows: green, FV18 (18 m); red, FV23 (23 m); and blue, FV36 (36 m).