Codon usage for aspartic acid in Clitellata mitochondrial genomes.

<p>Number of codons present in proteins used to code aspartic acid in Clitellata mitochondrial genomes. Even though all Hirudinea, except for <i>P</i>. <i>lamothei</i>, have a strong bias for the use of the GAT codon, they exclusively code for the <i>trnD</i> gene with a GUC anticodon.</p

Gene order from available mitochondrial genomes of Annelida.

<p>The phylogeny on the left was inferred by Bayesian methodology. Colors indicate each of the 13 different protein-coding genes present in the mitochondrial genomes. Genes are scaled to real length. Green lines connecting one horizontal bar to another track the position of tRNA gene rearrangements. Red lines are used to indicate duplication of tRNA genes. Red boxes around tRNA gene-names indicate putative rearrangements of tRNA genes relative to the mutual gene order for Clitellata. Red boxes around blocks of genes highlight syntenic regions, which may have been rearranged as a single unit. Blue boxes around blocks of genes denote inversions and, finally, incomplete or missing data are denoted by dashed lines. Names of RNA genes are denoted only when there has been a change in sequence, if RNA genes are not denoted, their sequence is equal to the closest sequence above for which genes are denoted. In some cases, however, minor rearrangements are present and these are then denoted with the names of the RNA genes involved and separated by “x”. For example, <i>trnA</i>x<i>trnS2</i> indicates that the <i>trnA</i> and <i>trnS2</i> genes have switched places. Gapped insertions inside <i>cox1</i> in <i>Endomyzostoma</i> sp. and <i>Nephtys</i> sp. indicate group II introns.</p

<i>trnD</i> duplication in <i>Placobdella</i>.

<p>Top: Secondary structures of <i>Placobdella trnD</i> genes as calculated by MITOS. Bottom: <i>trnD</i> sequences aligned against the 'Metazoa_D' model from MiTFi v0.1 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0155441#pone.0155441.ref077" target="_blank">77</a>] using cmalign from Infernal v1.1rc4 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0155441#pone.0155441.ref078" target="_blank">78</a>]; sequence alignments took into account the secondary structure of the <i>trnD</i> genes. Note that gaps in the alignment occur in the loop structures or the <i>trnD</i>’s.</p

Phylogenetic relationships of Annelida.

<p>Bayesian phylogenetic reconstruction as inferred by MrBayes with Myzostomida included, A, and excluded, B. Values above nodes are Bayesian posterior probabilities, and those below the nodes are parsimony bootstrap support values above 50%; asterisks denote maximum posterior probabilities and black circles denote maximum parsimony bootstrap support. Taxa in bold were sequenced for the present study and broken lines indicate the alternative positioning of the respective taxa in the single most parsimonious trees.</p

Mucosally invasive hirudinoid leeches.

<p>Known from a wide variety of anatomical sites including eyes (A) as in this case involving <i>Dinobdella ferox</i> (B), mucosal leech species, as in a case involving <i>Myxobdella annandalei</i> (C), more frequently feed from the nasopharyngeal surfaces of mammals (D).</p

Comparative internal and external anatomy of <i>Tyrannobdella rex.</i>

<p>(A) Whole body ventral view illustrating annulation, relative size of the caudal sucker and relative position of gonopores. (B) Eyespot arrangement illustrated dorsally. (C) Male and female median reproductive anatomy.</p

Single most parsimonious tree based on combined 18S rDNA, 28s rDNA, 12s rDNA, and COI datasets.

<p>The family Praobdellidae formed a well-supported monophyletic group of leeches that exhibits a predilection for mammalian mucosa. All groups received 100 percent bootstrap support and posterior probabilities of 1.00 except as noted on the tree. Branches are drawn proportional to amount of change.</p

Genes and primer sequences used in phylogenetic analyses.

<p>Genes and primer sequences used in phylogenetic analyses.</p

Taxa used for the phylogenetic analyses, collection localities, and GenBank accession numbers.

<p>Type species of genera are indicated with an asterisk.</p

Comparative jaw morphology of <i>Tyrannobdella rex</i>.

<p>(A) Stereomicrograph of the single dorsal jaw of <i>T. rex</i> with large teeth. Scale bar is 100 µm. (B) <i>Tyrannobdella rex</i> anterior sucker exhibiting velar mouth and longitudinal slit through which the dorsal jaw protrudes when feeding. Scale bar is 1 mm. (C) Compound micrograph in lateral view of eight large teeth of <i>T. rex</i>. Scale bar is 100 µm. (D) Lateral view of jaw of <i>Limnatis paluda</i> illustrating typical size of hirudinoid teeth. Scale bar is 100 µm.</p