Ambrysus amargosus, the Ash Meadows naucorid, is a small insect of the Naucoridae family.

[1] They live in the waters of Point of Rocks Springs, in the east-central region of Ash Meadows National Wildlife Refuge in Nye County, Nevada.

This insect is generally a dull brown in color with various dark yellow markings over their body.

The females drop their eggs close to the gravel floors of the springs, where they stick to the pebbles.

These are usually on the spring floors which make it easy for the naucorid to swim over and through the substrate and prey upon the larvae and plants.

[4] The Ash Meadows naucorid lives at the bottom of the hot springs, specifically underneath the rocky substrate.

The distribution suggests that the naucorid occupies the hot springs of the Ash Meadows National Refuge.

The ideal habitat is small thermal springs with high flowing water and fine, gravel substrate laying at the floor.

[3] However, as of September 2020, this insect can be found in only five low-flow spring brooks in the Point of Rocks region.

The Ash Meadows NWR plans to expand the range of the naucorid to the entirety of the Point of Rocks springs.

Groundwater depletion, scientific over-collection, and introduction of non-native species also threaten the population.

The Ash Meadows naucorid requires a specific habitat made of hot, high-flowing waters.

Nonnative fish and crayfish are the biggest predators of the Ash Meadows naucorid.

However, following October 13, 1983, the US Fish and Wildlife Service (USFWS) and ESA listed the species as endangered.

Its population size fluctuates depending on the season, with highs in the summer and lows in the winter.

Efforts to introduce new populations to previously inhabited spring brooks are being made by the Ash Meadows NWR.

The goal of these projects is to restore the endemic species to a wider range in the Point of Rocks Springs.