Monacanthidae
Dusky leatherjacket
Paramonacanthus otisensis
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.
Monacanthidae
Paramonacanthus otisensis
Cheilodactylidae
Dactylophora nigricans
Nototheniidae
Trematomus newnesi
Labridae
Scarus niger
Syngnathidae
Syngnathus floridae
Sebastidae
Sebastes ciliatus
Haemulidae
Plectorhinchus chubbi
Cottidae
Icelinus burchami
Kyphosidae
Girella freminvillii
Pomacentridae
Abudefduf concolor
Carcharhinidae
Carcharhinus galapagensis
Arhynchobatidae
Pavoraja umbrosa
Liparidae
Liparis gibbus
Clinidae
Ophiclinus antarcticus
Ophichthidae
Ophichthus cylindroideus
Scyliorhinidae
Bythaelurus naylori
Pleuronectidae
Lepidopsetta mochigarei
Siganidae
Siganus luridus
Holocentridae
Neoniphon vexillarium
Pempheridae
Pempheris adusta
Cynoglossidae
Paraplagusia sinerama
Aploactinidae
Aploactis aspera
Apogonidae
Taeniamia macroptera
Carangidae
Carangichthys humerosus
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.