Quantifying Morphological Variation in the Ornament and Shape of Dermal Scutes in Sturgeon (Acipenseridae)

Acipenseridae is a valuable taxonomic family, both ecologically and economically. They are ideal for morphological analysis in part because the family has existed for at least 70 million years, yet has remained largely anatomically static. The focus of this research is to quantify and compare the shape and ornamentation of scutes between species of Acipenseridae. With this as a baseline, future morphological analysis of the ornament and scute shape may be informative to study relatedness between these species. This metric could then be extended to other species of sturgeon to determine if scute shape and ornament similarity are indicative of sturgeon phylogeny. Statistically significant morphological differences in the general shape of the scute (measured in length : width, distance between landmarks, and landmark angles) were found solely between varying sequences and/or series. Significant differences between species were observed when comparing the ornament (cell) densities and areas. My data supports the discovery of statistically significant differences in aspects of scute morphology between series, sequence, and species. This is evident in the general shape of the scute, the ornament pattern, relative area measurements, and ornament measurements. These data do not demonstrate a clear relationship between sturgeon phylogeny and ornamented area of the scute. However, future morphological analysis of the ornament and scute shape, including larger sample sizes and additional taxa, may be informative to study the relatedness between species