Galaxiidae
Black Galaxias
Galaxias niger
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.
Black Galaxias
Apteronotidae
black ghost knifefish
Apteronotus albifrons
Horabagridae
Black Horabagrus
Horabagrus melanosoma
Salmonidae
Black Kokanee Salmon
Oncorhynchus kawamurae
Poeciliidae
Black lampeye
Micropanchax antinorii
Bagridae
Black lancer
Bagrichthys macracanthus
Cyprinidae
Black lined barb
Systomus pleurotaenia
Ictaluridae
Black madtom
Noturus funebris
Osphronemidae
Black Mask Chocolate Gourami
Parasphaerichthys lineatus
Cichlidae
Black midas cichlid
Amphilophus astorquii
Crenuchidae
Black morpho tetra
Poecilocharax weitzmani
Galaxiidae
Black mudfish
Neochanna diversus
Acestrorhamphidae
Black neon tetra
Hyphessobrycon herbertaxelrodi
Loricariidae
Black Oto
Otothyropsis piribebuy
Osphronemidae
Black paradise fish
Macropodus spechti
Acestrorhamphidae
Black phantom tetra
Megalamphodus megalopterus
Cichlidae
Black pin cichlid
Teleocichla preta
Prochilodontidae
Black prochilodus
Prochilodus nigricans
Catostomidae
Black redhorse
Moxostoma duquesnei
Ictaluridae
Black River madtom
Noturus maydeni
Cyprinidae
Black ruby barb
Pethia nigrofasciata
Cottidae
Black sculpin
Cottus baileyi
Cyprinidae
Black Sharkminnow
Labeo barbatulus
Cyprinidae
Black sharkminnow
Labeo chrysophekadion
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.