What ecological similarities and differences reveal about a status disparity between pallid sturgeon and shovelnose sturgeon

Some fishes with close phylogenetic relationships and similar ecological requirements exhibit a very different status in the wild and in responses to human-induced disturbance. This is the case with the US federally endangered pallid sturgeon Scaphirhynchus albus (Acipenseridae) and the more common shovelnose sturgeon S. platorynchus . We review the literature among the life stages for pallid sturgeon and shovelnose sturgeon to assess the degree of ecological overlap and discuss the implications of drawing inference from shovelnose sturgeon when considering potential management actions for pallid sturgeon. While shovelnose sturgeon have overlapping ecological requirements with pallid sturgeon at multiple life stages, differences between these species limit the utility of shovelnose sturgeon to inform conservation and management actions within specific life stages. For instance, the species have different free embryo drift distance requirements, but likely similar habitat requirements as juveniles and adult spawners. This example demonstrates the importance of understanding ecological differences when considering potential management actions from a surrogate species. Although the 2 congeners often exhibit ecological overlap, we encourage careful consideration when using surrogate data from shovelnose sturgeon to inform pallid sturgeon recovery efforts.