A comparative study of head morphology shape between Sibrean sturgeon (Acipenser baerii), Beluga sturgeon (Huso huso) and their diploid and triploid hybrids (male Siberian sturgeon × female Beluga) using geometric morphometrics technique

Polymorphism between the species of sturgeons due to natural hybridization, human manipulations and escaping hybrids from farms makes difficult their identification. Hence, this research was conducted to study the head shape differences between the Great beluga (Huso huso), Sibrean sturgeon (Acipenser baerii) and their diploid and triploid hybrids (male Siberian sturgeon × female Beluga) using geometric morphometric technique. In total 120 specimens (30 specimens from each group) were sampled. Nine, twelve and thirteen landmark points were digitized on 2D images of the lateral, dorsal and ventral views of their head, respectively, using TpsDig2. Landmark data after GPA, analyzed using CVA and MANOVA. The results showed significant differences among studied groups in the terms of head shapes in all three views (P