Meeting Abstract
If conical teeth are simply a tool used to puncture prey items, why is there such morphological diversity? We propose that they serve a wider variety of functions than their basic shape suggests. We use sharpness as a metric for determining the functions of conical teeth in the species Gonostoma gracile, Cyclothone atraria, and Stomias atriventer from two families of deep-sea fishes: the Dragonfish (Stomiidae) and Bristlemouths (Gonostomatidae). These Stomiiforme fishes share a common trait of conical teeth; however, gonostomatids feed primarily on zooplankton, while stomiids have adaptations for piscivory. We expected teeth to be sharper in piscivores. Additionally, we tested whether sharpness measurements are comparable between microCT and scanning electron microscopy (SEM). We found that sharpness is not an effective way to discern tooth function, as sharpness is correlated with tooth size. Teeth that are too small to effectively puncture prey items are sharper than larger teeth found in piscivorous Stomiiformes. Furthermore, for teeth between 250 μm and 2700 μm, the 18-25 μm resolution of the CT scanner was not sufficient to capture sharpness measurements that were measured by SEM. CT obscured true tooth height and shape and missed small morphological details, including damage. Further analysis of damage, tooth separation, and surface grooves appears to be a more promising tool for understanding how a tooth might be used, as these characters appear to correlate with gut content.
