Cyprinidae
fathead minnow
Pimephales promelas
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.
fathead minnow
Cyprinidae
Fatlips minnow
Phenacobius crassilabrum
Gobiidae
fatsnout rockclimbing goby
Sicyopterus pugnans
Cottocomephoridae
Fatty sculpin
Batrachocottus nikolskii
Mochokidae
Feather-barbelled squeaker
Synodontis manni
Cichlidae
Featherfin
Ophthalmotilapia ventralis
Cichlidae
featherfin cichlid
Cyathopharynx furcifer
Rivulidae
Featherfin pearlfish
Simpsonichthys constanciae
Mochokidae
Featherfin squeaker
Synodontis eupterus
Acestrorhamphidae
Featherfin tetra
Hemigrammus unilineatus
Cichlidae
Fenestratus Hap
Protomelas fenestratus
Salmonidae
Ferox trout
Salmo ferox
Badidae
Ferrari Badis
Badis ferrarisi
Poeciliidae
Festa toothcarp
Pseudopoecilia festae
Rivulidae
Festive Rivulus
Atlantirivulus luelingi
Poeciliidae
Few-spotted toothcarp
Poeciliopsis paucimaculata
Gobionidae
Field Gudgeon
Gnathopogon elongatus
Osphronemidae
Fierce Betta
Betta ferox
Cyprinidae
Fiery Redfin
Pseudobarbus phlegethon
Cyprinidae
Fieryblack shiner
Cyprinella pyrrhomelas
Eleotridae
fimbriate gudgeon
Oxyeleotris fimbriata
Callichthyidae
Fine spotted cory
Corydoras polystictus
Cyprinidae
Finescale dace
Chrosomus neogaeus
Cyprinidae
Finescale razorbelly minnow
Salmostoma phulo
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.