Citharinidae
Moon fish
Citharinus citharus
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.
Moon fish
Citharinidae
Moon fish
Citharinus latus
Serrasalmidae
Moon Pacu
Myloplus levis
Hiodontidae
mooneye
Hiodon tergisus
Osphronemidae
Moonlight gourami
Trichopodus microlepis
Osphronemidae
Moonspot Licorice Gourami
Parosphromenus linkei
Cichlidae
Moore's Lamprologus
Variabilichromis moorii
Cyprinidae
Morari
Cabdio morar
Mormyridae
Mormyrids
Mormyrus macrophthalmus
Mormyridae
Mormyrids
Mormyrus rume
Mormyridae
Mormyrids
Petrocephalus bovei
Mormyridae
Mormyrids
Petrocephalus simus
Apteronotidae
Mormyrus tube-snouted ghost knifefish
Sternarchorhynchus mormyrus
Blenniidae
Moroccan blenny
Salariopsis atlantica
Cobitidae
Moroccan Spined Loach
Cobitis maroccana
Cyprinidae
Moroco
Pseudorasbora pumila
Rhamphichthyidae
Morse Knifefish
Gymnorhamphichthys hypostomus
Cichlidae
Mortimer's happy
Sargochromis mortimeri
Callichthyidae
Mosaic corydoras
Corydoras haraldschultzi
Cyprinidae
Mostar minnow
Phoxinellus pseudalepidotus
Loricariidae
Moth Whiptail Catfish
Loricaria simillima
Polypteridae
Mottled bichir
Polypterus weeksii
Anabantidae
Mottled ctenopoma
Ctenopoma weeksii
Cichlidae
Mottled Dwarf Cichlid
Apistogramma gephyra
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.