Tucked under this bug’s head is a piercing proboscis, used to suck out body fluids from the animals it feeds upon. And jutting out from underneath its thorax is a powerful foreleg, used to grasp insects, mollusks and other prey in the stream riffles where it lives.

Most members of this insect family, the Naucoridae, come from tropical or subtropical Africa, Asia and Australia, but some live in fresh water in temperate areas. This imperiled species spends its life in a series of streams flowing from a single thermal spring in California’s Death Valley National Park. Over the years, people have diverted this water for irrigation and housing, putting these insects under pressure. If their streams are depleted enough, these water bugs, which are flightless, will find it very difficult to find a new home.