Cichlidae
Lake Victoria cichlid
Haplochromis argens
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.
Lake Victoria cichlid
Clariidae
Lake Victoria deepwater catfish
Xenoclarias eupogon
Mochokidae
Lake Victoria squeaker
Synodontis victoriae
Melanotaeniidae
Lake Wanam rainbowfish
Glossolepis wanamensis
Cyprinidae
Lakeweed Chub
Ischikauia steenackeri
Cyprinidae
Lambchop rasbora
Trigonostigma espei
Poeciliidae
Lambert's lampeye
Rhexipanchax lamberti
Alestidae
Lambert's Tetra
Nannopetersius lamberti
Cichlidae
Lamena
Paretroplus nourissati
Clariidae
Lamotte's Catfish
Clarias lamottei
Petromyzontidae
Lampetra appendix
Lethenteron appendix
Cobitidae
Lamprehuela
Cobitis calderoni
Gobiidae
Lampung Hill-stream Goby
Stiphodon carisa
Cyprinidae
Lamta garra
Garra lamta
Acestrorhamphidae
Lancet Toothy
Oligosarcus acutirostris
Eleotridae
Landford’s Gudgeon
Allomogurnda landfordorum
Gobionidae
Languedoc gudgeon
Gobio occitaniae
Cyprinidae
Languedoc minnow
Phoxinus septimaniae
Cyprinidae
Lanigar Barbel
Luciobarbus lanigarensis
Cyprinidae
Lanka blue laubuka
Laubuka lankensis
Nemacheilidae
Lanquedoc stone loach
Barbatula quignardi
Cyprinidae
Lantern minnow
Tampichthys ipni
Siluridae
Lanzhou Catfish
Silurus lanzhouensis
Adrianichthyidae
Laos Medaka
Oryzias pectoralis
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.