Cyprinidae
Dixie chub
Semotilus thoreauianus
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.
Dixie chub
Cyprinidae
Dnieper barbel
Barbus borysthenicus
Rivulidae
Dogtooth rivulus
Cynodonichthys tenuis
Sisoridae
Doi Tung Bat Catfish
Oreoglanis suraswadii
Cyprinidae
Doiran bleak
Alburnus macedonicus
Centrarchidae
Dollar sunfish
Lepomis marginatus
Characidae
Dollar Tetra
Tetragonopterus argenteus
Cichlidae
Dolphin cichlid
Krobia itanyi
Serrasalmidae
Dolphin Pacu
Mylesinus paucisquamatus
Gobionidae
Don gudgeon
Gobio brevicirris
Cobitidae
Don Spined Loach
Cobitis tanaitica
Cyprinidae
Don whitefin gudgeon
Romanogobio tanaiticus
Percidae
Donets ruffe
Gymnocephalus acerina
Bryconidae
Dorada
Brycon moorei
Bryconidae
Dorado
Salminus brasiliensis
Doradidae
Doras
Ossancora punctata
Claroteidae
Dotted catfish
Parauchenoglanis monkei
Cichlidae
Dotted dwarf cichlid
Apistogramma guttata
Nemacheilidae
Dotted Loach
Schistura semiarmata
Cyprinidae
Dotted Sawfin Barb
Pethia punctata
Osphronemidae
Double Lipspot Mouthbrooder
Betta spilotogena
Cichlidae
Double Stripe
Haplochromis thereuterion
Mormyridae
Double-nosed Elephant Nose
Campylomormyrus rhynchophorus
Gobiidae
Double-Spotted Dwarfgoby
Pandaka bipunctata
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.