Cobitidae
Louros spined loach
Cobitis hellenica
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.
Louros spined loach
Salmonidae
Louros Trout
Salmo lourosensis
Cyprinidae
Loveridge's barb
Enteromius loveridgii
Salmonidae
lower Amur grayling
Thymallus tugarinae
Mormyridae
Lower Congo River mormyrid
Mormyrus cyaneus
Cichlidae
Lowland cichlid
Herichthys carpintis
Galaxiidae
lowland longjaw galaxias
Galaxias cobitinis
Cyprinidae
Lowland shiner
Pteronotropis stonei
Cichlidae
Lowveld largemouth
Serranochromis meridianus
Mochokidae
Lowveld suckermouth
Chiloglanis swierstrai
Poeciliidae
Lualaba lampeye
Lacustricola lualabaensis
Cyprinidae
Luambwa barb
Enteromius cercops
Balitoridae
Ludong hillstream loach
Balitora ludongensis
Cichlidae
Lueling's Dwarf Cichlid
Apistogramma luelingi
Cyprinidae
Luika barb
Enteromius luikae
Cyprinidae
luma
Labiobarbus ocellatus
Acestrorhamphidae
Lunar Poptella
Poptella compressa
Cobitidae
Luther's spiny loach
Cobitis lutheri
Cyprinidae
Lydian barbel
Luciobarbus graecus
Cichlidae
Lyon's Cichlid
Amphilophus lyonsi
Rivulidae
Lyrefin pearlfish
Simpsonichthys boitonei
Nothobranchiidae
Lyretail panchax
Aphyosemion australe
Bryconidae
Macabí Tetra
Brycon guatemalensis
Acestrorhamphidae
Macal Tetra
Astyanax macal
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.