Four-eyes | Anableps anableps
Characins / Characidae / Four-eyes
Profile: Four-eyes, Four-eyed Fish
Anableps anableps Synonyms: Anableps anonymus, A. gronovii, A. lineatus, A. surinamensis, A. tetrophthalmus, Cobitis anableps
Physical description: The body is long and cylindrical, while the head is flat with protruding eyes. The back is flat and the dorsal fin is small and set far back on the back. The thick pectoral fins are paddle-shaped. The back is olive to gray and the flanks are gray-yellow to white with a violet to white iridescence under some lights. The eye is separated into two separate parts by a narrow bridge of tissue.
Size/Length: To 12" (30 cm)
Similar species: A. dowi, A. microlepis
Habitat: Brackish water tidal river estuaries in Central and South America; on the Atlantic Coast from Southern Mexico to Columbia
Aquarium: A tank measuring 48" (122 cm) with a capacity of 50-70 gallons (190-266 L) is sufficient. The tank must only have a depth of 8-12" (20-30 cm) and should have a large surface area. The tank should have a beach, or some partly emerged stones or wood, as this species likes to leave the water. Have a tight-fitting cover. Use a good filtration system for this species produces a lot of waste.
Water chemistry: pH 7-8.5 (7.5), 8-25 dH (14), 75-81°F (24-27°C). The water should have a 2.5-3% addition of salt. This can be accomplished by adding 19-23 TSP. of salt/10 gallons (25-30 g/10 L)
Social behavior: A large, schooling fish that is best kept in groups of 6-10 fish. This species, due to its different tank set-up, is limited to a specific community tank. Small fish may be consumed.
Suggested companions: Archerfish, Mudskippers, Scats, Arius, Monos
FOOD: Live; fish, earthworms, Tubifex, flying insects, insect larvae, crustaceans; pellets; flakes. Foods are taken off the surface and rarely off the bottom.
SEX: Males have a gonopodium.
Breeding techniques: In a large tank with favorable conditions, breeding is likely. Fish are mature at about 8 months, when the fish measure 6-8" (15-20 cm). After a gestation period of eight weeks, the 2-2.8" (5-7 cm) fry are born. These rarely number more than 15, and stillborns are likely. The fry should be removed and placed in a tank of their own with a water level of 4-6" (10-15 cm). Start feeding with Artemia, insect larvae, and Drosophila. The young grow quickly.
Breeding potential: 6. A fairly easily bred fish, under favorable conditions. The main trouble arises with the general maintenance of this species.
Remarks: The upper parts of the eye which are usually emerged above the water, allow the Four-eyes to spot predators lurking above the water. Four-eyes are strong jumpers. The gonopodium of males is twisted either to the right or left as is the genital opening of the female. Thus right-sided males can only mate with left-sided females, and vice versa.
Difficulty of care: 6. A large species with special tank requirements. This species requires a diet that includes live foods. Frequent partial water changes are a must for this messy species that produces copious amounts of waste.