The structure and surface morphology of gill filaments in the brown mussel Perna perna

Abstract

The morphology of the gills of adult Perna perna were examined by stereo light-microscopy and scanning electron microscopy. While the surface morphology of each filament was similar to that previously described for Mytilus edulis, there were some subtle inter-generic differences. In M. edulis, inter-lamellar connections are reported to connect the inner and outer lamellae over the entire ventral to dorsal surface. In P. perna, the inter-lamellar connections are restricted to between the third and sixth row of cilial disks from the marginal groove. All cilia emanating from the epithelial cells of M. edulis are reportedly longer than those of their counterparts in P. perna. Further, laterofrontal cirri in M. edulis comprises 22-30 pairs of cilia, whereas in P. perna there are only 18-23 pairs. This report complements an earlier fine-structural study and completes the description of gill filaments in P. perna. These data serve as a morphological baseline for future local pollution impact studies.