Poeciliidae
Cuban gambusia
Gambusia punctata
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
SCROLL
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.
Cuban gambusia
Fundulidae
Cuban Gulf Killifish
Fundulus saguanus
Poeciliidae
Cuban topminnow
Girardinus cubensis
Kneriidae
Cubango kneria
Parakneria fortuita
Mochokidae
Cuckoo Catfish
Synodontis petricola
Catostomidae
cui-ui
Chasmistes cujus
Percidae
Cumberland darter
Etheostoma gore
Percidae
Cumberland darter
Etheostoma susanae
Percidae
Cumberland plateau darter
Etheostoma spilotum
Percidae
Cumberland snubnose darter
Etheostoma atripinne
Cichlidae
Cunene happy
Sargochromis coulteri
Kneriidae
Cunene kneria
Kneria maydelli
Cyprinidae
Cunene Labeo
Labeo ansorgii
Cyprinidae
Curmuca Barb
Hypselobarbus curmuca
Percidae
Current darter
Etheostoma uniporum
Potamotrygonidae
Cururu Ray
Potamotrygon wallacei
Cichlidae
Curve-bar cichlid
Herichthys labridens
Cyprinidae
Cutlips minnow
Exoglossum maxillingua
Cichlidae
Cutter's Cichlid
Cryptoheros cutteri
Alestidae
Cyaneyed Tetra
Phenacogrammus aurantiacus
Cichlidae
cylinder cichlid
Neolamprologus cylindricus
Gymnotidae
Cylindrical Knifefish
Gymnotus cylindricus
Percidae
Cypress darter
Etheostoma proeliare
Cyprinidae
Cypress minnow
Hybognathus hayi
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.