The larger species – namely the orange roughy (Hoplostethus atlanticus) and Darwin's slimehead (Gephyroberyx darwinii) – are the target of extensive commercial fisheries off Australia and New Zealand.

Many populations have already crashed, while others are showing signs of severe overfishing; due to slimeheads' slow rate of reproduction, the future viability of these fisheries has been put into question.

The most elongate species are typically the most active and frequent the shallowest depths; for example, the slender roughy (Optivus elongatus) is found in photic coastal waters and is associated with rocky reefs.

Both young and adult slimeheads feed primarily upon zooplankton such as mysid shrimp, amphipods, euphausiids, prawns, and other crustaceans, as well as larval fish.

The aggregations form in and around geologic structures, such as undersea canyons and seamounts, likely where water movement and mixing is high, ensuring dense concentrations of prey items.

Observations of orange roughy aggregations during submersible dives have also shown the fish lose almost all pigmentation while inactive, during which time they are very approachable.

Slimeheads are pelagic spawners; that is, spawning aggregations are formed and the fish release eggs and sperm en masse directly into the water.