and can survive for long periods out of water, as first described for
Diplecogaster bimaculata in 1891 Clingfishes mainly inhabit shallow rocky reefs and shores,
coral reefs,
seagrass meadows and
algae beds. They often live in places exposed to strong currents and wave action, and some are
amphibious. As long as the strongly amphibious,
intertidal-living species are kept moist by splashing waves, they can survive for up to three–four days on land, gaining oxygen from the air by the
branchial surfaces (
gills), skin and perhaps the mouth. At least a few species even tolerate a relatively high degree of water loss when on land. Three clingfish species, the Australian
Cochleoceps bicolor and
C. orientalis, and the warm East Atlantic
Diplecogaster tonstricula, are
cleaner fish that will cling onto the bodies of larger fish. Although several species can occur in
brackish water, only seven (
Gobiesox cephalus,
G. fluviatilis,
G. fulvus,
G. juniperoserrai,
G. juradoensis,
G. mexicanus and
G. potamius) from warmer parts of the Americas are freshwater fish that live in fast-flowing rivers and streams. Most known clingfish species are from relatively shallow coastal waters, but several inhabit the
mesophotic zone and a few even deeper, with
Alabes bathys,
Gobiesox lanceolatus,
Gymnoscyphus ascitus,
Kopua kuiteri,
K. nuimata and
Protogobiesox asymmetricus reported from depths of . Because of their small size and typical habitat, it is however suspected that still-undiscovered deep-water species remain. As a consequence their abundance is often not well known. Several species are only known from a single or a few
specimens. Species that appear uncommon or rare based on standard methods can actually be common if using methods that are more suitable for detecting them. Studies of better-known species have shown that they can be locally abundant. As many as 23 individuals of
Lepadogaster lepadogaster have been documented from a single square metre (more than two individuals per square foot). , the
IUCN has evaluated the conservation status of 84 clingfish species (roughly half the species in the family). The majority of these are considered
least concern (not threatened), 17 are considered
data deficient (available data prevents an evaluation), 8 considered
vulnerable and a single
endangered. The vulnerable and endangered species all have small distributions, restricted to islands or a single bay. Three
Gobiesox species that are restricted to fresh water in Mexico have not been rated by the IUCN, but are considered threatened by Mexican authorities. ==Description==