Being a predaceous diving beetle, it is aquatic and primarily found in lentic, or still-water, habitats, as well as valleys.

[3] Distinctive physical traits of C. explanatus include the sharp points of the hind legs’ metafemora and the yellow lining of the elytra and pronotum's margins.

[5] Their use as food traces back to prehistoric times, as revealed by a mid-1900s excavation project of caves in Nevada.

Cybister explanatus remains were in human coprolites, or fossilized dung, attributed to the Humboldt Sink.

In modern times, this practice for eating dytiscids continues, since commercial producers give the same advice.

In addition, Cybister explanatus is part of the subgenus Nealocomerus due to being endemic to the Nearctic region.

[8] One identifying feature of Cybister explanatus is the stripe of yellow often surrounding both sides of the elytra's epipleura and the margins of the pronotum in front of it.

[1] The coloration of the dorsal side, which includes the tops of the head, pronotum, and elytra, varies from green to brown-black.

Cybister explanatus is present from extreme southern Oregon through California and Nevada and in western Mexico from the north all the way down to the southernmost state of Chiapas.

[1] H. F. Wickham described the movement of Cybister explanatus as lazy compared to northern water beetles.

[11] Meanwhile, the individuals that James G. Needham found were highly active, with such a ferocious appetite as to exhibit cannibalism.