Gempylidae
black snoek
Thyrsitoides marleyi
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.
Gempylidae
Thyrsitoides marleyi
Nototheniidae
Patagonotothen tessellata
Holocentridae
Neoniphon opercularis
Acanthuridae
Acanthurus gahhm
Tripterygiidae
Enneapterygius niger
Gobiidae
Cabillus atripelvicus
Ceratiidae
Ceratias uranoscopus
Labridae
Halichoeres adustus
Pomacentridae
Neoglyphidodon nigroris
Tripterygiidae
Enneapterygius similis
Sebastidae
Sebastes chrysomelas
Anthiadidae
Epinephelides armatus
Pomacentridae
Chromis atripectoralis
Clinidae
Ophiclinus gracilis
Pomacentridae
Amblypomacentrus breviceps
Platycephalidae
Rogadius patriciae
Labridae
Bodianus macrourus
Aracanidae
Capropygia unistriata
Lutjanidae
Lutjanus semicinctus
Sillaginidae
Sillago nigrofasciata
Acanthuridae
Acanthurus polyzona
Stomiidae
Stomias atriventer
Diodontidae
Diodon liturosus
Syngnathidae
Corythoichthys nigripectus
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.