Acestrorhamphidae
Mimic scale-eating tetra
Deuterodon heterostomus
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.
Mimic scale-eating tetra
Cyprinidae
Mimic Shiner
Notropis volucellus
Cyprinidae
Mimic shiner
Paranotropis volucellus
Cichlidae
Minckley's cichlid
Herichthys minckleyi
Cyprinidae
Mindanao rasbora
Rasbora philippina
Astroblepidae
Mindo climbing catfish
Astroblepus mindoensis
Ophichthidae
Mindora Snake Eel
Lamnostoma mindora
Cichlidae
Mini-severum
Heroina isonycterina
Cichlidae
Mini-Zebra
Cynotilapia zebroides
Cyprinidae
Minnow
Hemiculter bleekeri
Acestrorhamphidae
Minor Tetra
Hyphessobrycon minor
Poeciliidae
Miragoane gambusia
Gambusia beebei
Poeciliidae
Miragoane limia
Limia miragoanensis
Loricariidae
Mirim Pleco
Hypostomus pusarum
Alestidae
Mirror Robber
Brycinus rhodopleura
Acestrorhamphidae
Mirror Toothy
Oligosarcus paranensis
Chalceidae
Mirror-scale Chalceus
Chalceus spilogyros
Bryconidae
Mirrorbelly Brycon
Brycon chagrensis
Atherinopsidae
Mississippi silverside
Menidia audens
Cyprinidae
Mississippi silvery minnow
Hybognathus nuchalis
Percidae
Missouri saddled darter
Etheostoma tetrazonum
Eleotridae
Mitchell gudgeon
Hypseleotris hutchinsi
Poeciliidae
Mizola toothcarp
Priapella lacandonae
Poeciliidae
Moa gambusia
Gambusia bucheri
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.