Cichlidae
Masked julie
Julidochromis transcriptus
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.
Masked julie
Cyprinidae
Masya's barb
Puntius masyai
Catostomidae
Matalote Conchos
Catostomus conchos
Adrianichthyidae
Matano medaka
Oryzias matanensis
Loricariidae
Mato Grosso Black Pleco
Hypostomus froehlichi
Doradidae
Mato Grosso Mouse Catfish
Hassar shewellkeimi
Cyprinidae
Matthes' barb
Labeobarbus acuticeps
Trichomycteridae
Mauri catfish
Trichomycterus rivulatus
Bagridae
Mavelikkara Mystus
Mystus catapogon
Cyprinidae
mavrotsironi
Pachychilon macedonicum
Poeciliidae
Maya gambusia
Gambusia echeagarayi
Cyprinodontidae
Maya Pupfish
Cyprinodon maya
Acestrorhamphidae
Maya Tetra
Hyphessobrycon compressus
Poeciliidae
Mayan Swordtail
Xiphophorus mayae
Chilodidae
Maze Headstander
Caenotropus labyrinthicus
Loricariidae
Maze King Pleco
Pterygoplichthys lituratus
Nothobranchiidae
Mbam killi
Aphyosemion dargei
Cyprinidae
Mbaraga
Acapoeta tanganicae
Mochokidae
Mbozi suckermouth
Chiloglanis mbozi
Eleotridae
Mbuta Mogurnda
Mogurnda mbuta
Cichlidae
McConnel's haplo
Haplochromis macconneli
Galaxiidae
McDowall’s Galaxias
Galaxias mcdowalli
Cyprinodontidae
Media Luna Pupfish
Cualac tessellatus
Serrasalmidae
Medina's Piranha
Serrasalmus medinai
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.