Cichlidae
brown julie
Julidochromis dickfeldi
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.
brown julie
Siluridae
Brown leaf catfish
Silurichthys ligneolus
Ictaluridae
Brown madtom
Noturus phaeus
Galaxiidae
Brown mudfish
Neochanna apoda
Lebiasinidae
Brown pencilfish
Nannostomus eques
Loricariidae
Brown sucker catfish
Otothyris lophophanes
Acestrorhamphidae
Brown's Tetra
Moenkhausia browni
Cichlidae
Brownae Hap
Haplochromis brownae
Cichlidae
Brownspot largemouth
Serranochromis thumbergi
Profundulidae
Brownspotted Killifish
Profundulus punctatus
Nothobranchiidae
Bruening's killi
Scriptaphyosemion brueningi
Pseudopimelodidae
Brunette Bumblebee Catfish
Microglanis berbixae
Mochokidae
Bubblebarb squeaker
Synodontis thamalakanensis
Stevardiidae
Buck-Toothed Tetra
Creagrutus bolivari
Parodontidae
Buckley's Characin
Parodon buckleyi
Characidae
Bucktooth tetra
Exodon paradoxus
Acestrorhamphidae
Buenos Aires tetra
Psalidodon anisitsi
Clariidae
Buettikofer's Catfish
Clarias buettikoferi
Cichlidae
Buettikofer's Cichlid
Pelmatochromis buettikoferi
Percidae
Buffalo darter
Etheostoma bison
Mochokidae
Bugeye squeaker
Synodontis contractus
Cichlidae
Bujurqui
Bujurquina syspilus
Nemacheilidae
Bukhara stone loach
Dzihunia amudarjensis
Poeciliidae
Bukoba lampeye
Lacustricola bukobanus
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.