Gobiesocidae
3 species
Clingfishes are fishes of the family Gobiesocidae, the only family in the order Gobiesociformes. These fairly small to very small fishes are widespread in tropical and temperate regions, mostly near the coast, but a few species in deeper seas or fresh water. Most species shelter in shallow reefs or seagrass beds, clinging to rocks, algae and seagrass leaves with their sucking disc, a structure on their chest.
They are generally too small to be of interest to fisheries, although the relatively large Sicyases sanguineus regularly is caught as a food fish, and some of the other species occasionally appear in the marine aquarium trade.
Clingfishes are primarily found near the shore in the Atlantic, Indian and Pacific Oceans, including marginal seas such as the Mediterranean, Gulf of Mexico, Caribbean and Gulf of California. The greatest species richness is in tropical and warm temperate regions, but the range of a few extends into colder waters, like Diplecogaster bimaculata (north to Norway), Apletodon dentatus, Lepadogaster candolii and L. purpurea (all three north to Scotland; the last formerly mistaken for the mostly Mediterranean L. lepadogaster), Gobiesox maeandricus (north to Alaska), Gobiesox marmoratus and Sicyases sanguineus (both to southernmost South America), and Gastrocymba quadriradiata (from New Zealand's subantarctic islands).
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.
A relatively small number of species shelter in sea urchins or crinoids. Whether this relationship is obligate (clingfish always with a sea urchin or crinoid) or facultative (clingfish sometimes with a sea urchin or crinoid) varies with species. In some, only young clingfish are obligate and gradually move away as they become adult. 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 300–560 m (980–1,840 ft). Because of their small size and typical habitat, it is however suspected that still-undiscovered deep-water species remain. Even in shallow coastal waters many clingfish are highly cryptic and easily overlooked, mostly staying under cover, although there are species that are active and will swim in the open. 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). As of 2018, 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.
Clingfishes are fishes of the family Gobiesocidae, the only family in the order Gobiesociformes. These fairly small to very small fishes are widespread in tropical and temperate regions, mostly near the coast, but a few species in deeper seas or fresh water. Most species shelter in shallow reefs or seagrass beds, clinging to rocks, algae and seagrass leaves with their sucking disc, a structure on their chest.
They are generally too small to be of interest to fisheries, although the relatively large Sicyases sanguineus regularly is caught as a food fish, and some of the other species occasionally appear in the marine aquarium trade.
Clingfishes are primarily found near the shore in the Atlantic, Indian and Pacific Oceans, including marginal seas such as the Mediterranean, Gulf of Mexico, Caribbean and Gulf of California. The greatest species richness is in tropical and warm temperate regions, but the range of a few extends into colder waters, like Diplecogaster bimaculata (north to Norway), Apletodon dentatus, Lepadogaster candolii and L. purpurea (all three north to Scotland; the last formerly mistaken for the mostly Mediterranean L. lepadogaster), Gobiesox maeandricus (north to Alaska), Gobiesox marmoratus and Sicyases sanguineus (both to southernmost South America), and Gastrocymba quadriradiata (from New Zealand's subantarctic islands).
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.
A relatively small number of species shelter in sea urchins or crinoids. Whether this relationship is obligate (clingfish always with a sea urchin or crinoid) or facultative (clingfish sometimes with a sea urchin or crinoid) varies with species. In some, only young clingfish are obligate and gradually move away as they become adult. 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 300–560 m (980–1,840 ft). Because of their small size and typical habitat, it is however suspected that still-undiscovered deep-water species remain. Even in shallow coastal waters many clingfish are highly cryptic and easily overlooked, mostly staying under cover, although there are species that are active and will swim in the open. 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). As of 2018, 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.
