Synonyms: Rivulus macrurus
Physical description: An elongated species with elaborate fins. Males have a brownish back and brownish-pearl colored flanks with a violet to silver iridescence in reflected light. The flanks are marked with rows of small iridescent green or yellow spots. Just beyond the gill cover, males have a black and red marking. The fins are also brownish-pearl colored with irregular brown markings, and the tips of the pelvic fins are white. The fins of males are far more complex than those of females, which are shorter and rounded. Females are duller in body coloration.
Size/Length: To 4" (10 cm)
Similar species: The Peruvian Longfin ( Pterolebias Peruensis) of Peruvian Amazon reaches 4.7" (12 cm). The Lace-finned Killifish ( P. zonatus) is another similar species.
Habitat: Marshy, floodplain zones that frequently dry up. South America; in the Lower Amazon of Brazil and Argentina.
S: bottom, middle
Aquarium: 24" (60 cm) or 10-15 gallons (38-57 L) is sufficient. Provide dense planting with a cover of floating plants to diffuse the overhead lighting. The tank should be arranged in dark colors with a peat substrate.
Water chemistry: pH 6-7.2 (6.5); 3-12 dH (5); 64-73°F (18-23°C)
Social behavior: Males are aggressive toward one another and should be only kept one to a tank with two or three females. A large number of males (more than six) can usually be safely kept in a tank as their aggression is dispersed. Suggested companions: This species is best kept in a species, although it can be combined with small schooling characins and small catfish.
FOOD: Live; insect larvae, Artemia, insects, Tubifex; flakes.
SEX: Males are larger, more colorful, and have more elaborate fins.
Breeding techniques: Use water temperatures between 68-75°F (20-24°C), a pH from 6.2-6.5, and water hardness of 2-5 dH. The small tank should include a peat moss substrate and retreats for the female. Place one mature female with two or three mature females. The eggs are laid in the peat. Remove the peat and place it in a plastic bag for two or three months. Place the peat in a tank containing soft water with a depth of 2-6" (5-15 cm). Raise the fry on powdered foods and Artemia nauplii.
Breeding potential: 7. Breeding is moderately difficult.
Remarks: An annual species that rarely live longer than 16 months in captivity.
Difficulty of care: 6. This species is sensitive to changes in water chemistry, so small frequent water changes are recommended.
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