Eastern newts (Notophthalmus viridescens) are a ubiquitous member of eastern North America’s caudate fauna. Unlike the typical amphibian, their life cycle is split into three phases instead of two, commonly called a triphasic life cycle. The larvae of N. viridescens are fully aquatic, eventually metamorphosing to become terrestrial juveniles called efts. Upon sexual maturity, the eft will metamorphose into a semi-aquatic adult whose external morphology resembles other aquatic salamander species. The eastern newt has predominantly been described by its external traits, namely color changes and lateral tail compression, rather than the musculoskeletal system and anatomy. Since these salamanders occupy different ecological niches (aquatic vs. terrestrial) throughout their lives and likely experience different forces acting on their skeletons, they provide a unique opportunity to study internal changes across ontogeny and ecology. We hypothesize that differences in buoyancy, torsion, and locomotion are expected to result in morphological shape changes across the life stages of the eastern newt’s skeleton. Using image data generated on a SkyScan 1273 micro-computed tomography (µCT) scanner (Bruker), 3D shape analyses will quantify shape differences between individual bones and test the hypothesis. Three-dimensional digital models of each bone of interest will be rendered from the scans in Dragonfly (Object Research Systems). Each 3D model is loaded into SlicerMorph (3DSlicer), where 3D geometric morphometrics is conducted for each bone to test for potential shape differences between each life stage. Our results support a shape difference between eft and adult in particular bones and conserved shape across ontogeny in other bones. Differences in shape are associated with a difference in functional demand across ecological niches.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:asrf-2099 |
| Date | 25 April 2023 |
| Creators | Hardgrave, Aaron J, Carter, Richard T |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | Appalachian Student Research Forum |
Page generated in 0.0021 seconds