Ctenoluciidae
Golden pike-characin
Boulengerella lucius
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.
Golden pike-characin
Percichthyidae
golden pygmy perch
Nannoperca variegata
Catostomidae
Golden Redhorse
Moxostoma erythrurum
Rivulidae
Golden Rivulus
Anablepsoides amphoreus
Rivulidae
Golden Rivulus
Atlantirivulus haraldsiolii
Loricariidae
Golden Sailfin Pleco
Hypostomus luteus
Cichlidae
Golden Sandeater
Lethrinops auritus
Atherinopsidae
Golden silverside
Labidesthes vanhyningi
Atherinopsidae
golden silverside
Menidia colei
Goodeidae
Golden skiffia
Skiffia francesae
Cobitidae
Golden spined loach
Sabanejewia aurata
Gobiidae
Golden Sulawesi Goby
Mugilogobius rexi
Cyprinidae
Golden Systomus
Systomus chryseus
Acestrorhamphidae
Golden Tetra
Hyphessobrycon moniliger
Fundulidae
golden topminnow
Fundulus chrysotus
Cichlidae
Golden Tropheops
Tropheops tropheops
Salmonidae
Golden trout
Oncorhynchus aguabonita
Botiidae
Golden Zebra Loach
Sinibotia pulchra
Cichlidae
Golden-headed Dwarf Cichlid
Nannacara aureocephalus
Cyprinidae
Golden-line barbel
Sinocyclocheilus grahami
Gobiidae
Golden-red stiphodon
Stiphodon rutilaureus
Characidae
Goldencrown tetra
Aphyocharax alburnus
Hiodontidae
goldeye
Hiodon alosoides
Cyprinidae
Goldfin tinfoil barb
Hypsibarbus malcolmi
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.