Organisms are subdivided into eurybate (bathos - depth) and stenobate depending on their relationship to pressure.

Stenobate organisms are hydrobnotes that live at a certain or varying water pressure.

From the Greek stenos - narrow and bathos - depth.

Aquatic animals and plants that live only at some depth, especially those that inhabit the seafloor. These include most littoral and bottom-dwelling marine animals. For example, Stingrays, starfish, anglerfish, etc.

Stenobate organisms living at shallow depths are called shallow-water organisms, while those living at greater depths are called deep-water organisms. For example, some species of holothuria are found at depths of 100-9000 m, and many pogonophores, cephalopod mollusks, and fish at depths of over 5-6 km.