Comparative Ontogeny of the Siberian Sturgeon, Acipenser baerii (Acipenseriformes: Acipenseroidei: Acipenseridae), the Sterlet, Acipenser ruthenus and their Hybrids

• Main Author: Desai, Anu
• Format: Text
• Language: English
• Published: W&M ScholarWorks 2024
• Subjects: Marine Biology; Other Ecology and Evolutionary Biology; Acipenser baerii; Siberian sturgeon
• Online Access: https://scholarworks.wm.edu/honorstheses/2073; https://scholarworks.wm.edu/context/honorstheses/article/3088/viewcontent/Anu_Desai___Final_Honors_Thesis.pdf

Owing to their more rapid growth rate and overall improved reproductive fitness, hybrids between species of sturgeons (Acipenser spp.) have increasingly accounted for a critical mass of the fish reared in captivity for the growing industry surrounding these fishes. In spite of their commercial importance, little information exists regarding the ontogeny of these hybrids in comparison to their parent species. The aim of this study was to examine the morphological differences and overall patterns of growth that the hybrids of two purebred sturgeon that are commonly used in aquaculture, the Siberian Sturgeon (Acipenser baerii), and Sterlet (Acipenser ruthenus), in relation to both of these parent species. The developmental timing of the pectoral fin, dorsal fin, pelvic fin, and anal fin were quantified along with the relationship between the total length of each individual and the position of the fin, with the goal of testing for morphological hybrid vigor (earlier or accelerated development of critical functional units in the hybrids than in the parent species). While the data that were collected did not conclusively support morphological hybrid vigor for all traits, the maternal inheritance pattern that was observed in the developmental timing of the dorsal and pelvic fin in the A. baerii (female) x A. ruthenus (male) cross potentially provided support for a separate hypothesis that has only recently been explored in the literature, stating that A. baerii has a “dominant phenotype,” in turn potentially offsetting any instance of hybrid vigor that would otherwise occur. While possible explanations for this phenomenon exist – i.e., the differences in ploidy level between A. baerii and A. ruthenus – an exact cause may need to be determined through the course of future studies.