Clariidae
African catfish
Heterobranchus bidorsalis
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.
African catfish
Schilbeidae
African Glass Catfish
Pareutropius debauwi
Notopteridae
African knifefish
Xenomystus nigri
Polycentridae
African leaffish
Polycentropsis abbreviata
Alestidae
African moon tetra
Bathyaethiops caudomaculatus
Channidae
African obscure snakehead
Parachanna obscura
Hepsetidae
African pike
Hepsetus odoe
Alestidae
African Rainbow Tetra
Alestopetersius nigropterus
Cyprinidae
African redfinned barb
Enteromius camptacanthus
Cyprinidae
African scraping feeder
Labeobarbus beso
Channidae
African snakehead
Parachanna africana
Alestidae
African Spottail Tetra
Brachypetersius altus
Distichodontidae
African Striped Darter
Nannocharax fasciatus
Amphiliidae
African whiptailed catfish
Phractura ansorgii
Callichthyidae
Agassiz's corydoras
Corydoras agassizii
Cichlidae
Agassiz's dwarf cichlid
Apistogramma agassizii
Ambassidae
Agassiz's Glassfish
Pseudoambassis agassizii
Cyprinidae
Agdam dace
Squalius agdamicus
Cobitidae
Aggitis spined loach
Cobitis punctilineata
Alosidae
Agone
Alosa agone
Cyprinidae
Agulhas Redfin
Pseudobarbus agulhas
Nothobranchiidae
Ahl's killi
Aphyosemion ahli
Erythrinidae
Aimara
Hoplerythrinus unitaeniatus
Heteropneustidae
Air-sac Catfish
Heteropneustes kemratensis
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.