The scatterplot displaying the positive association between the length and width of eggs of diphyllobothriid cestodes.

<p><i>A</i>, Based on 56 samples of 8 species from various definitive hosts. <i>B</i>, Based on 3 commonest species infecting humans for 25 samples exclusively from man. Ellipses represent 95% confidence intervals about the means indicating greater correlation between length and width in a given species. Details for individual samples are listed in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004721#pntd.0004721.t001" target="_blank">Table 1</a>.</p

Maximum likelihood (ML) estimate of <i>Diphyllobothrium dendriticum</i> phylogenetic relationships based on currently available cox<i>1</i> sequences of human-infecting <i>Diphyllobothrium</i> species and their close relatives computed in Garli 2.0.

<p>Nucleotide data matrix was 1563; codon positions were analyzed separately according to the partition scheme and models (TrN+I) (F81) (TrN+I+G) chosen according to the BIC in PartitionFinder 1.0.1. Nodal support values depict bootstrap support proportions >50 based on 1,000 repetitions estimated in Garli. Note that the <i>D. pacificum</i> branch was shortened by a factor of two. Newly obtained sequences are shown in bold type; country of origin is listed for <i>D. dendriticum</i> infections.</p

Descriptive statistics for measurements of eggs of 8 diphyllobothriidean species studied from natural (samples from same hosts are pooled).

<p>Range and means are given in micrometers for the 3 parameters subjected to morphometrical studies. Details for individual samples are listed in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004721#pntd.0004721.t001" target="_blank">Table 1</a>. Measurements are in micrometers (μm).</p

Intraspecific variability of egg sizes of selected diphyllobothriid species.

<p><i>A</i>, <i>Adenocephalus pacificus</i> from 7 host species. <i>B</i>, <i>Diphyllobothrium latum</i> from 4 host species. <i>C</i>, <i>Diphyllobothrium cordatum</i> from 3 host species. Data represent mean values for length (in black) and width (in white). Whiskers indicate maximum and minimum values of measured eggs, boxes standard deviation of the mean and circles inside of boxes the mean value.</p

Summary data for egg samples of diphyllobothriidean cestodes from naturally infected hosts used in analysis of variance (one-way ANOVA) statistics assessing interspecific and intraspecific variation in sizes (length, width and length/width ratio).

<p>See <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004721#pntd.0004721.t001" target="_blank">Table 1</a> for data on hosts.</p

Comparison of the means of 3 morphometrical parameters (length in circles, width in squares and length to width ratio in triangles) measured on eggs of 8 species of diphyllobothriid cestodes.

<p>Black and white arrows indicate pairs/groups of species for which statistical difference of particular parameter was not detected, thus showing similar values for these features. Species differing in all tested parameters is marked with a square (<i>A</i>. <i>pacificus</i>) and can be easily distinguished from the remaining species.</p

Scanning electron micrographs of eggs of marine (m) and freshwater /anadromous (f) diphyllobothriid cestodes and their surface.

<p><i>A</i>–<i>B</i>, <i>Adenocephalus pacificus</i> (m) ex <i>Canis mesomelas</i> (<i>A</i>) and <i>Arctocephalus australis</i> (<i>B</i>). <i>C</i>–<i>D</i>, <i>Diphyllobothrium latum</i> (f) ex <i>C</i>. <i>lupus</i> (<i>C</i>) and <i>Homo sapiens</i> (<i>D</i>). <i>E</i>, <i>D</i>. <i>dendriticum</i> (f) ex <i>C</i>. <i>familiaris</i>. <i>F</i>–<i>H</i>, <i>D</i>. <i>nihonkaiense</i> (f) ex <i>H</i>. <i>sapiens</i>. <i>I</i>, <i>D</i>. cf. <i>cameroni</i> (m) ex <i>Neomonachus schauinslandi</i>. <i>J</i>, <i>D</i>. <i>cordatum</i> (m) ex <i>Erignathus barbatus</i>. <i>K</i>, <i>D</i>. <i>hians</i> (m) ex <i>Monachus monachus</i>. <i>L</i>, <i>D</i>. <i>stemmacephalum</i> (m) ex <i>Lagenorhynchus acutus</i>. Figures are showing eggs and their surface in the same magnification 10.000×.</p

Sequences of <i>Diphyllobothrium dendriticum</i> used in phylogenetic analysis (Figure 1).

<p>sequences of <i>Diphyllobothrium ursi</i>;</p><p>see van Doorn et al. 2005 <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002535#pntd.0002535-vanDoorn1" target="_blank">[20]</a>.</p

Geographical distribution and human cases of <i>Diphyllobothrium dendriticum</i>.

<p>Black dots represent autochthonous human cases; white dots represent imported human cases. Black line delimits the area of <i>D. dendriticum</i> distribution (grey colour).</p

Photomicrographs of the surface of diphyllobothriid eggs observed by light microscopy.

<p><i>A</i>, marine species <i>Diphyllobothrium cordatum</i> ex <i>Erignathus barbatus</i> covered by numerous deep pits. <i>B</i>, anadromous species <i>Diphyllobothrium nihonkaiense</i> ex <i>Homo sapiens</i> smooth or with isolated shallow hollows or wrinkles.</p