[5] The 5th edition of Fishes of the World classifies this family within superfamily Cyclopteroidea, part of the suborder Cottoidei of the order Scorpaeniformes.

[6] Other authorities do not recognise this superfamily and classify the two families within it, Cyclopteridae and Liparidae, within the infraorder Cottales alongside the sculpins, within the order Perciformes.

Mariana hadal snailfish also have adjusted to pressure due to a mutation in bglap which prevents cartilage calcification, revealed in their skulls.

Snailfish are scaleless with a thin, loose gelatinous skin which surrounds the spine and can vary in terms of size and shape between species.

The deep-sea species have prominent, well-developed sensory pores on the head, part of the animals' lateral line system.

In some species such as the antarctic Paraliparis devriesi, the pectoral fins have an expanded somatosensory system, including a taste bud.

Research has revealed that maximum depth of living can be a significant predictor for loss of the pelvic disk in certain species of snailfish.

[3][14][15] They are common in most cold marine waters and are highly resilient, with some species, such as Liparis atlanticus and Liparus gibbus, having type-1 antifreeze proteins.

[12] The diminutive inquiline snailfish (Liparis inquilinus) of the northwestern Atlantic is known to live out its life inside the mantle cavity of the scallop Placopecten magellanicus.

[14][22] Snailfish (notably genera Notoliparis and Pseudoliparis) are the most common and dominant fish family in the hadal zone.

[22] Pseudoliparis swirei possesses multiple molecular adaptations to the intense pressures of a deep sea environment, including highest-known contents of TMAO [refs.

Additionally, at least one species of snailfish that utilize the golden king crab as a host, Careproctus pallidus, has larvae with a lower energy content than normal for most marine fish.

[34] Otolith analysis (the investigation of snailfish ear bone) gives insight into longevity by seeing how it is broken into alternating translucent and opaque zones.

Many species are located in hadal trenches, which are inherently high-disturbance areas, including lots of seismic activity which can trigger turbidity flows.

[35] Little is known about snailfish courtship behavior but males of Careproctus pallidus are believed to wiggle their bodies as attractive or aggressive display.

The larval diet of three Beaufort Sea snailfish species contained 28 food categories, mainly copepods and amphipods.

[38] Snailfish prey fall into six main categories: gammarid, krill, natantian decapods, other crustaceans, fish, and others.

[39] With the Okhotsk snailfish (Liparis ochotensis), the ratio between food intake and body weight changes as the organism grows; it is also highly seasonally variable.

[40] The snailfish that live in the northern hemisphere also display a higher starvation tolerance, which may be due to the triglycerol and cholesterol levels in this species.