HELENA, Mont. — FROM an evolutionary perspective, the pallid sturgeon is a thing of beauty.

Its eyes are a bit beady, it’s true, but good vision is not a prerequisite for living on the bottom of the Missouri River. And its toothless mouth, with its protruding, whiskerlike barbels, is creepy. But these barbels are perfect for sensing food, which it sucks in like a vacuum cleaner.

No, these fish are not sleek and beautiful like trout. But this species of sturgeon, which can grow to a length of six feet and weigh as much as 80 pounds, has managed to survive since the time of the dinosaurs, with fossils dating back some 70 million years.

For all of the adaptations that have enabled this fish to have such a long run, however, the pallid sturgeon is in serious trouble. Twenty-five years ago, the federal government concluded the fish was in imminent danger of extinction and placed it on the endangered species list, where it remains today.

Despite government efforts to expand the population, only perhaps 200 or fewer wild-born pallid sturgeons are thought to inhabit one of its last strongholds — the Montana stretches of the Missouri and Yellowstone Rivers.