Synonyms: Acara subocularis, Geophagus cupido
Physical description: A cichlid with a rounded forehead and an elongated caudal penuncle. The dorsal and pelvic fins are elongated, and the caudal fin is fan-shaped. Different color varieties exist. A common variation has a gray back . The flanks are marked with fine transverse stripes that may or may not be visible. A black spot is located on the rear, upper-part of the fish. A black band runs through the eye from the forehead to the corner of the gill cover. The coloration changes (depending on the angle of light) from orange to yellow to green to blue and finally, to purple as it nears the caudal fin. This rainbow of colors develop only in mature specimen that are kept in exceptionally maintained water. Young fish are dull gray. The dorsal fin is pinkish-red, while the anal fins is a dark violet. The tail may be grayish-green. The pelvic fin is turquoise in color.
Size/Length: To 5.5" (14 cm), although usually smaller
Similar species: Biotodoma wavrini
Habitat: Found is slow-moving, wide parts of clear rivers. South America; Rio Tapajo near Santarèm (Brazil). S: bottom, middle
Aquarium: A tank measuring 32" (81 cm) with a capacity of 30 gallons (114 L) is sufficient. The foreground should include a fine gravel or sand substrate, and be open. The background should include hiding places among thickets of hardy plants, roots, caves, and wood.
Water chemistry: pH 5-7 (6.5), dH 0-6 dH (2), 77-84°F (25-29°C).
Social behavior: A territorial and somewhat aggressive fish that should be kept in pairs. Problems with pairing are common, so allow a group of youngsters to pair off, and select the best pair. This species should be kept with calm, small to medium-sized fish of the upper swimming levels. Pairs form a nuclear family.
Suggested companions: Tetras, Headstanders, larger hatchetfish, Loricarids, Pimelodus, Armored catfish, dwarf Acaras
FOOD: Live; insect larvae, crustaceans, Tubifex; flakes, pellets.
SEX: Males have blue iridescent lines on their cheeks, while females have spots.
Breeding techniques: Use water with a pH from 6.0-6.5, a water hardness of 0-4 dH, and a temperature from 81-84 F (27-29 C). The female will dig a pit with its mouth in the substrate. The female lays about 100 eggs which are guarded by the male, with the female caring for the eggs. When the are free-swimming about 10 days later, they can be fed roftiers and liquid foods. After another week or two, they are large enough to be given brine shrimp nauplii. The parents continue their care for the young. The fry are difficult to raise.
Breeding potential: 8. Breeding is difficult.
Remarks: Fish of the genus Biotodoma can be distinguished from other Geophagus, by their smaller snouts and mouth. The Cupid Cichlid is sensitive to changes in water conditions and pollutants. Wild-caught specimen are much more colorful, although they are also far more delicate.
Difficulty of care: 6. A delicate species that may, at times be aggressive towards others of its own species.
Pearl Cichlid, Mother-of-Pearl Eartheater
 "Geophagus" brasiliensis
Synonyms: Acara brasiliensis, Chromis brasiliensis, Geophagus labiatus, G. obscura, G. pygmaeus
Physical description: A laterally compressed cichlid with a rounded forehead. The anal, dorsal, and caudal fins are large when compared to those of other Eartheaters. The back is dark and the belly is salmon-pink. The body color ranges from yellow to brown to dark red, and each scale is marked with a blue, green, or yellow spot. The fins retain the scale pattern and coloring, except to have more blue and violet hues. The iris of the eye is golden with a black band running through it. A lateral stripe, sometimes unnoticeable, runs from the eye to the base of the caudal fin. Fish under 3" (8 cm) are an unattractive brown color. Size/Length: Males to 12" (30 cm) in nature, although no larger than 9" (23 cm) in captivity. Females reach 6" (15 cm) in captivity.
Similar species: "Geophagus" gymnogenys
Habitat: South America; found in the coastal rivers of Brazil. This Eartheater is found along rocky banks of rivers that receive tidal influence.
Aquarium: A tank measuring 48" (122 cm) with a capacity of 55 gallons (209 L) is needed for adult sized fish. Use a substrate of fine gravel or sea sand-for buffering the pH. The tank should be arranged with rock structures including caves. Only robust, potted plants should be used.
Water chemistry: pH 6.7-8.2 (7.3), 5-20 dH (11). This species can tolerate a temperature as low as 50°F (10°C) for short periods of time, although it can be kept in a cool tropical set-up with temperatures from 66-75°F (18-24°C).
Social behavior: A territorial, but peaceful species that is tolerant of other fish, including Eartheaters. Combine with medium to large sized fishes. Pairs form monogamous bonds and nuclear families.
Suggested companions: Catfish (Arius, Callichthys, Loricarids, Pimelodids, Doradids), characins (Silver Dollars, Headstanders), cichlids (Eartheaters, Cichlasomines).
FOOD: Live; Tubifex , crustaceans, snails, crabs; chopped meat; mussels; pellets; tablets.
SEX: Males develop nuchal humps on their forehead with age. The male reaches a larger size and has a more elongated dorsal fin. The genital papilla of the male is pointed.
Breeding techniques: Use water with a pH from 6.5-7.2, a water hardness from 5-10 dH, and a temperature from 75-79°F (24-26°C). Condition the pair with nutritious live foods. As many as 800 eggs are deposited on a previously cleaned surface that is usually hidden. The parents are fine parents which carefully care for the fry. Start feeding with crushed dry foods and Artemia nauplii. The young grow quickly when fed often and kept in well-maintained water. The eggs may be consumed in cases where a compatible pair is not found.
Breeding potential: 6. Breeding is fairly easy.
Remarks: A 0.5% addition of salt can be used. This can be accomplished by adding 4 TSP. of salt per every 10 gallons (5 g of salt/10 L).
Difficulty of care: 4. A hardy fish recommended for the aquariast wanting to begin keeping Eartheaters.
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