The effect of neuromast position on bone fragmentation in the third suborbital bone of Astyanax mexicanus

Abstract

By Tess Palluzzi, Biology of Animals; Rachel Rowland, Biological Science

Advisor: Josh Gross

Presentation ID: PM_ATRIUM26

Abstract: Many structural differences can be observed pertaining to the craniofacial development between the cave- and surface-dwelling forms of Astyanax mexicanus. Previous studies have shed light on the mechanisms involved in the asymmetric fragmentation of a craniofacial bone known as suborbital 3 (SO3). The purpose of this experiment is to determine if there is any correlation between the placement of sensory organs, called neuromasts, and the direction of a carving event on the SO3 bone. This was achieved by utilizing two live-staining techniques that are known to bind to bone and neuromasts. Juvenile fish were imaged under fluorescents on a weekly basis for several weeks in order to see carving progress over time. Based on findings thus far, carving seems to take place near the posterior of the SO3 and tend to follow a crescent shaped path laid out by the neuromasts. Many individuals are still in the early carving stage so further analysis in the coming weeks will help determine if the neuromasts do indeed predetermine the fate of SO3 fragmentation in Astyanax mexicanus.