<p><span style="font-size: 13.008px;"><strong>Fig. 3.57.</strong> Molluscs breathe using gills called ctenidia as shown in the sea slug, <em>Pleurobranchaea meckelii</em>.</span></p>

Fig. 3.57. Molluscs breathe using gills called ctenidia as shown in the sea slug, Pleurobranchaea meckelii.

Image adapted from Heike Wägele & Annette Klussmann-Kolb, BioMed Central