Percidae
Guadalupe darter
Percina apristis
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.
Guadalupe darter
Cyprinidae
Guadalupe Roundnose Minnow
Dionda flavipinnis
Cyprinidae
Guadalupe roundnose minnow
Dionda nigrotaeniata
Loricariidae
Guajupia Pleco
Hypostomus guajupia
Poeciliidae
Guama guppy
Micropoecilia minima
Rivulidae
Guanabara Rivulus
Atlantirivulus guanabarensis
Chalceidae
Guapore Chalceus
Chalceus guaporensis
Doradidae
Guaporé thorny catfish
Amblydoras affinis
Cichlidae
Guapote
Parachromis dovii
Callichthyidae
Guaramiranga cory
Aspidoras rochai
Percidae
Guardian darter
Etheostoma oophylax
Characidae
Guatemalan headstander
Roeboides guatemalensis
Profundulidae
Guatemalan Killifish
Profundulus guatemalensis
Cichlidae
Guayas cichlid
Mesoheros festae
Cichlidae
Guenther's mouthbrooder
Chromidotilapia guntheri
Cyprinidae
Guercif barbel
Luciobarbus guercifensis
Belonidae
Guianan Needlefish
Potamorrhaphis guianensis
Polypteridae
Guinean bichir
Polypterus ansorgii
Nothobranchiidae
Guinean killi
Archiaphyosemion guineense
Cichlidae
Guinean Tilapia
Coptodon discolor
Loricariidae
Guitar Whiptail Catfish
Loricaria lata
Aspredinidae
Guitarrita
Bunocephalus coracoideus
Nothobranchiidae
Gulare
Fundulopanchax gularis
Cyprinidae
Gulf chub
Macrhybopsis tomellerii
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.