Left–right asymmetry of the visual system in the scallop <i>Nodipecten nodosus</i> (Bivalvia: Pectinidae)

ABSTRACT Left–right asymmetries are consistent differences between the left and right sides represent an intriguing feature of molluscan morphology. Interestingly, external asymmetries, such as inequivalve shells, often coupled with lateralization in nervous system, which includes functional structural specializations or sides. In case visual lateralized phenotypes frequently include left–right eye position, structure use. To investigate among bivalves, we examined systems scallop Nodipecten nodosus. We characterized different morphologies species determined eye-side frequencies. also studied anatomy focusing on parietovisceral ganglion (PVG). Our results reveal that N. nodosus comprise asymmetries: (1) a greater number eyes side, (2) increased size PVG lateral lobe, (3) larger glomeruli lobe (4) radial pallial nerves associated spaced more widely than compactly arranged lobe. addition, distinctive morphology, where optic vesicle is rotated, frequent side. Considering habit this to rest valve, hypothesize curved might contribute expanding overall field. Even though bivalves not typically considered literature lateralization, accumulating evidence for scallops, suggested by our results, indicates their potential novel patterns asymmetry benthic invertebrates.