Cottidae
Amur Sculpin
Mesocottus haitej
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.
Amur Sculpin
Cobitidae
Amur Weatherfish
Misgurnus mohoity
Cyprinidae
Amur whitefin gudgeon
Romanogobio tenuicorpus
Balitoridae
Anamalai loach
Ghatsa montana
Cyprinidae
Anatolian Barbel
Barbus pergamonensis
Cyprinidae
Anatolian Ghizani
Ladigesocypris irideus
Aphaniidae
Anatolian giant killifish
Anatolichthys anatoliae
Cyprinidae
Anatolian Khramulya
Capoeta tinca
Cyprinidae
Andalusian Barbel
Luciobarbus sclateri
Astroblepidae
Andean catfish
Astroblepus ubidiai
Cyprinodontidae
andean killifish
Orestias empyraeus
Cyprinodontidae
Andean Killifish
Orestias forgeti
Cyprinodontidae
Andean Killifish
Orestias gracilis
Cyprinodontidae
Andean Killifish
Orestias incae
Cyprinodontidae
Andean Killifish
Orestias jussiei
Cyprinodontidae
Andean killifish
Orestias luteus
Trichomycteridae
Andean Pencil Catfish
Trichomycterus dispar
Callichthyidae
Andes cory
Corydoras micracanthus
Lebiasinidae
Anduzi's Nannostomus
Nannostomus anduzei
Osphronemidae
Angel Licorice Gourami
Parosphromenus anjunganensis
Mochokidae
Angel squeaker
Synodontis angelicus
Chacidae
Angler catfish
Chaca bankanensis
Cichlidae
Angolan happy
Chetia welwitschi
Clariidae
Angolian walking catfish
Clarias angolensis
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.