Incidence of endoliths: micro-scale comparison between shaded and non-shaded sites.

<p>Mean (+SD) percentage of <i>M. galloprovincialis</i> and <i>P. perna</i> shells that exhibited damage induced by endolithic infestation, at shaded and non-shaded sites.</p

Degrees of infestation of different size classes: micro-scale comparison between bays and open coast.

<p>Proportions of shells exhibiting different degrees of infestation severity (Groups A–E, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006560#pone-0006560-g001" target="_blank">Fig. 1</a>) and grouped into 10 mm size classes. Infestation severity was determined in the mid-mussel zone at (a) bay and (b) open coast habitats for <i>P. Perna</i> and at (c) bay and (d) open coast for <i>M. galloprovincialis.</i></p

Degrees of infestation of different size classes: micro-scale comparison between shaded and non-shaded sites.

<p>Proportions of shells exhibiting different degrees of infestation severity (Groups A–E, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006560#pone-0006560-g001" target="_blank">Fig. 1</a>) and grouped into 10 mm size classes. Infestation severity was determined in the mid-mussel zone at (a) shaded and (b) non-shaded sites for <i>P. Perna</i> and at (c) shaded and (d) non-shaded sites for <i>M. galloprovincialis</i>.</p

Incidence of endoliths: meso-scale comparison between bays and open coast.

<p>Incidence of endoliths: meso-scale comparison between bays and open coast.</p

Examples of shells at varying stages of endolith infestation.

<p>Group A, shells with clean, intact periostracum and distinct outer lines; Group B, shells with central portion of surface eroding, outer striation on periostracum becoming indistinct; Group C, shells with erosion spreading past central portion, grooves and pits appearing on the shell surface; Group D, shells heavily pitted and becoming deformed, outer striation on periostracum almost completely absent; Group E, shells extremely pitted, deformed and brittle, eventually holed.</p