While the Comprehensive Sturgeon Research Project (CSRP) at the USGS Columbia Environmental Research Center (CERC) is focused on pallid sturgeon (Scaphirhynchus albus) and the closely-related shovelnose sturgeon (S. platorynchus), the CERC also conducts behavioral, physiological and toxicological research on other sturgeon species. Those species include the shortnose sturgeon (Acipenser brevirostrum), lake sturgeon (Acipenser fulvescens), and white sturgeon (Acipenser transmontanus).
In order to study the early life stages of sturgeon species in the laboratory, it is important to learn how to propagate (breed) and culture (grow) them. James Candrl, a fish biologist at CERC, has been supporting the CSRP by breeding and caring for sturgeon since 2001. In the 2011 spring and summer, James raised four different species of sturgeon for studies on diet and starvation, early behavior, and the effects of environmental contaminants on survival and development. Each of these experiments has one thing in common – the need for live, healthy sturgeon eggs, larvae, and juveniles. James knows that ”the better you are at propagating and culturing sturgeon, the better your experiment will be.” So, through research and observation, he strives to raise healthy fish, comparable to what might be in the wild.
Click here to view a short video of a pallid sturgeon embryo. As hatch time nears, sturgeon embryos become more active inside the chorion (egg shell).
Unlike many other fish species, pallid sturgeon eggs and newly hatched larvae are fairly big. However, because the large and muddy Missouri River is home to the pallid sturgeon, it is difficult to observe these early life stages in the wild. Therefore, many studies seeking to understand this time in the pallid sturgeon life cycle must be conducted in the laboratory. Studies that examine early development and behavior provide insight into how far newly hatched sturgeon drift, what habitats are needed when sturgeon begin feeding, what juvenile sturgeon eat, and how long a young sturgeon can go without feeding. These experiments help predict if they survive in the wild and what may happen if food sources are limiting in the river.
Laboratory studies are very helpful in conducting field work, too. Research at the CERC helps guide scientists when and where to sample for larval pallid sturgeon, so they may have the greatest success in catching a drifting fish. In the event that a larval sturgeon is captured in the river, knowledge gained from laboratory studies will help determine how old the fish is as well as when and where its parents spawned.
Completed with contributions by Aaron DeLonay and James Candrl.