Ophidiidae
bank cusk-eel
Ophidion holbrookii
FISH SPECIES
Saltwater fish, also called marine fish, live in seas and oceans. They range from small reef residents to fast open-ocean swimmers and species that stay close to the seabed.
01 / NATURAL HISTORY
Marine fish regulate water and salts in a very different environment from freshwater fish. Body form often reflects where they live: streamlined swimmers cross open water, while compressed or camouflaged species maneuver around complex habitats.
02 / LIFESTYLE
Marine fish occupy a vast, three-dimensional environment with shifting currents, light gradients and depths. Open-water pelagic species often school to travel efficiently and confuse predators, while reef residents navigate complex crevices between foraging patches. Along the coast and continental shelves, tidal cycles and changing sunlight dictate daily peaks of activity and shelter seeking.
OBSERVATION INDEX
03 / SPECIES
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
Ophidiidae
Ophidion holbrookii
Sebastidae
Sebastes rufus
Serranidae
Centropristis ocyurus
Cheilodactylidae
Chirodactylus grandis
Chaenopsidae
Emblemaria atlantica
Gobiidae
Microgobius microlepis
Carangidae
Caranx ruber
Platycephalidae
Platycephalus endrachtensis
Dasyatidae
Maculabatis ambigua
Muraenidae
Gymnothorax baranesi
Stomiidae
Eustomias enbarbatus
Agonidae
Agonomalus proboscidalis
Agonidae
Agonomalus jordani
Gobiesocidae
Apletodon barbatus
Sciaenidae
Ctenosciaena gracilicirrhus
Hemerocoetidae
Acanthaphritis barbata
Exocoetidae
Exocoetus monocirrhus
Clinidae
Cirrhibarbis capensis
Parascylliidae
Cirrhoscyllium expolitum
Epinephelidae
Paranthias furcifer
Gobiidae
Elacatinus figaro
Anthiadidae
Caesioperca rasor
Chaetodontidae
Johnrandallia nigrirostris
Scorpaenidae
Scorpaena brasiliensis
04 / FIELD NOTES
Yes. Because surrounding seawater is saltier than their internal fluids, marine bony fish constantly lose water by osmosis, requiring them to drink seawater continuously and pump excess salts out via gill cells.
No. Coral reefs represent only a fraction of marine environments; the vast majority of marine species inhabit open pelagic waters, continental shelves, or the deep ocean floor.
Yes. Euryhaline and migratory species like salmon, bull sharks and European eels actively adjust their osmotic regulation between fresh and marine waters.