Description
Overview:
The Four-Eyed Fish is a fascinating and highly unusual surface-dwelling species named for its split eyes, which allow it to see above and below the water simultaneously. Sleek and silvery with a streamlined body, it is an active swimmer that thrives in long tanks with open surface space. This brackish-water oddball is a conversation piece for experienced aquarists seeking something truly different.
Origin:
Native to Central and South America, from Trinidad and Venezuela down to the Amazon Basin and northern Brazil. Found in brackish estuaries, tidal flats, and coastal rivers, often swimming in schools near the surface.
Feeding:
Omnivorous with a preference for insects and small invertebrates at the water’s surface. Accepts floating pellets, flakes, freeze-dried foods, and live/frozen fare such as bloodworms, brine shrimp, and mosquito larvae. Feed floating foods to accommodate their surface-feeding style.
Tank Mates:
Peaceful but best housed with other brackish-water species of similar size, such as mollies, scats, monos, and archerfish. Avoid aggressive fish or fin-nippers. Best kept in groups of 4+ for natural schooling behavior.
Water Parameters:
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Temperature: 75–82°F (24–28°C)
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pH: 7.5–8.5
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Brackish salinity: 1.005–1.015 SG
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Minimum Tank Size: 55 gallons (long tanks preferred)
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Keep water well-oxygenated with gentle current
Behavior & Personality:
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Skims the surface, rarely diving to the bottom
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Uses its unique eyes to hunt insects above water and spot predators below
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Social, active, and constantly on the move
Special Notes:
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Requires brackish water long-term; not suited to pure freshwater
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Excellent jumpers—tight-fitting lid essential
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Males and females have asymmetrical gonopodia and mate side-specific, so breeding requires matching pairs
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Fascinating species for advanced or specialized aquarists
The Four-Eyed Fish (Anableps anableps) is a true oddity of the fish world, combining unique anatomy with lively behavior—perfect for aquarists ready to maintain a dedicated brackish-water setup.
