A Morphological Assessment of Salvelinus sp. (Subgenus Baione)

Mueller, Sara

ABSTRACT: The taxonomy of Brook Trout (Salvelinus fontinalis) has recently been under scrutiny. Throughout its range from New Foundland to Georgia, Brook Trout are treated as a single species despite population fragmentation and isolation. In 2014, a neotype was designated along with six distinct genetic lineages. In 2020, three new species of Salvelinus were described in Great Smoky Mountain National Park. Herein I use computed tomography (CT) scans in combination with an automated three-dimensional geometric morphometric (auto3dgm) approach to differentiate between the neotype and Pennsylvanian populations. The statistically significant difference in skull shape indicates that Salvelinus occurring in Pennsylvania are Salvelinus c.f. fontinalis. Then, I describe a new species of Salvelinus in the subgenus Baione. Using a truss-based network of landmarks for a total of 25 measurements and 10 counts, a sheared principal component analysis reveals no overlap in the neotype population and two populations from the Sinnemahoning watershed (Susquehanna River Drainage) for both PC1 (meristics) and sheared PC2 (morphometrics). Finally, I analyze the color and pattern variation of Salvelinus from pictures submitted by anglers across Pennsylvania. These pictures allow for the examination of the number and color of red spots and the number of parr marks on a variety of sizes of Salvelinus. This study supports the otherwise anecdotal nature of the variation observed by anglers. It proves that anglers are willing to support and actively participate in collecting data for scientific research.