Rajidae
African dwarf skate
Neoraja stehmanni
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.
Rajidae
Neoraja stehmanni
Pseudochromidae
Haliophis guttatus
Lutjanidae
Apsilus fuscus
Opistognathidae
Opistognathus afer
Etmopteridae
Etmopterus polli
Labridae
Cirrhilabrus africanus
Labridae
Pseudojuloides polackorum
Carangidae
Alectis ciliaris
Serranidae
Serranus inexpectatus
Proscylliidae
Eridacnis sinuans
Pleuronectidae
Poecilopsetta natalensis
Exocoetidae
Parexocoetus mento
Carangidae
Trachurus delagoa
Pomacentridae
Abudefduf hoefleri
Pempheridae
Pempheris tominagai
Grammistidae
Rypticus africanus
Ephippidae
Tripterodon orbis
Ophichthidae
Mystriophis rostellatus
Pentanchidae
Holohalaelurus punctatus
Haemulidae
Parapristipoma octolineatum
Pempheridae
Pempheris connelli
Carangidae
Alectis alexandrina
Labridae
Pseudocoris occidentalis
Rhinidae
Rhynchobatus luebberti
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.