Ontogenetic Changes to Sensory Modality in Early Life History Stage Drums (Family Sciaenidae) from the Chesapeake Bay

The link between the structure of the feeding apparatus, sensory modality (a sense or combination of senses relied on by an organism) and diet in early life history stage fishes is important for understanding ontogenetic shifts in foraging habitats during ontogeny. Species of the family Sciaenidae are used to examine how ontogenetic changes in feeding structures and sensory modalities correspond to diet. Sciaenids occupy a broad spectrum of feeding niches, possess varying mouth structures and rely on different senses to find prey. We observed differentiation of the feeding apparatus between benthic sciaenids (sciaenids that forage in or along the substrate) and pelagic sciaenids (forage in the water column) by 35 mm standard length. To investigate sensory modality, the relative size of sensory brain regions will be determined using micro-CT imaging and staining techniques and compared between ontogenetic stages. Although sciaenids possess the ability to forage in different habitats, there is still dietary overlap, suggesting that sensory development may influence when sciaenids can partition their niches more so than feeding apparatus development. It is hypothesized that benthic sciaenids will use senses other than vision to locate prey whereas pelagic species will primarily use vision to locate prey at all stages.