Cyprinidae
Moapa dace
Gila coriacea
FISH SPECIES
Freshwater Fish
Freshwater fish spend all or part of their lives in rivers, lakes, streams and wetlands. The label describes an environment, not one branch of the fish family tree, so freshwater species include many unrelated shapes and lineages.
FISH ATLAS / FIELD GUIDEFreshwater FishIN THIS CHAPTER01 / Characteristics02 / Lifestyle03 / Species04 / Field notes
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01 / NATURAL HISTORY
Characteristics
Freshwater habitats contain far less salt than seawater and can change quickly with seasons, floods and drought. Fish living there use many different strategies, from streamlined bodies for current to barbels that help find food near the bottom.
- 01River fish
- 02Lake fish
- 03Stream fish
02 / LIFESTYLE
Lifestyle
Life in freshwater follows the movement of water and food. Some fish hold position in a current and intercept drifting prey; others search plants or sediment for a meal. Changes in flow and water level can open feeding grounds or trigger movements toward spawning areas. These behaviors reflect how fish balance hydrodynamic energy expenditure against food intake.
OBSERVATION INDEX
- Holding position in a current
- Feeding among plants or sediment
- Movement with changing water levels
03 / SPECIES
Representative species
Discover representative species illustrating the ecological diversity, morphologies and adaptations of this group.
Moapa dace
Cyprinidae
Mobile chub
Macrhybopsis boschungi
Percidae
Mobile logperch
Percina kathae
Poeciliidae
Moctezuma Swordtail
Xiphophorus montezumae
Catostomidae
Modoc Sucker
Catostomus microps
Poeciliidae
Moero lampeye
Lacustricola moeruensis
Cichlidae
Moga
Hypsophrys nicaraguensis
Cyprinidae
Moggel
Labeo umbratus
Stevardiidae
Mojarita
Knodus gamma
Polypteridae
Mokèlé-mbèmbé Bichir
Polypterus mokelembembe
Cyprinidae
Mola carplet
Amblypharyngodon mola
Cyprinidae
Moltrecht's minnow
Aphyocypris moltrechti
Cichlidae
Mongo
Stomatepia mongo
Salmonidae
Mongolian grayling
Thymallus brevirostris
Cyprinidae
Mongolian Redfin
Chanodichthys mongolicus
Doradidae
Monitor Catfish
Amblydoras monitor
Apteronotidae
Montanus tube-snouted ghost knifefish
Sternarchorhynchus montanus
Cichlidae
Montecristo cichlid
Oscura heterospila
Mormyridae
Monteiri's bulldog
Marcusenius monteiri
Gobiidae
Montenegro Dwarf Goby
Knipowitschia montenegrina
Cyprinidae
Montenegro riffle dace
Telestes montenigrinus
Salmonidae
Montenegro trout
Salmo montenigrinus
Poeciliidae
Monterrey Platyfish
Xiphophorus couchianus
Serrasalmidae
Moon dollar
Metynnis luna
04 / FIELD NOTES
A closer look
What makes a fish freshwater?
It is recorded from inland waters with low salinity for all or part of its life cycle.
Are all freshwater fish closely related?
No. Freshwater is a habitat category that includes many separate evolutionary groups.
Can freshwater fish survive in seawater?
Most cannot; without physiological adaptations to excrete excess salt, their cells rapidly lose water through osmosis and dehydrate in hypertonic seawater.