Butterfly goodeid

Geographic Origin and Biotope: Endemic to Mexico, once abundant in the Ameca river basin. It now survives in the wild only in small isolated springs (hot and strongly alkaline biotopes) being on the brink of extinction in its original habitat (Critically Endangered).

Taxonomy and Morphology: Family of the Goodeids (Goodeidae). Stocky fish, very high on the back, equipped with massive fins and a slightly superior mouth. Reaches 8 cm (3 inches) for females and about 6-7 cm for males.

Social Behavior: Marked gregariousness with a hierarchical and pugnacious temperament. They are not fish for quiet communities: they are restless, intrusive and manifest the odious habit of biting fins ("fin-nipping") to any slow tankmate.

Coloration and Sexual Dimorphism: Chromatically splendid males: flanks of a metallic shine with emerald green reflections, interrupted by black spots, with a flashy and wide bright golden-yellow band bordered with black that adorns the caudal fin. Females uniformly olive-gray with black spotting all over the body.

Aquarium Setup: Tank starting from 100 liters (25 gallons), dedicated to a single school (species-tank). Calcareous rocks to guarantee hardness and filamentous algae or mosses. Given the aptitude to graze continuously, they will destroy soft-leaved plants; prefer Java ferns and Anubias.

Diet and Feeding: In nature they are formidable algae grazers. In the aquarium they will clean every surface of filamentous and brush algae. The diet must be 70% vegetable (spirulina flakes, boiled spinach). Too much protein rapidly leads to fatty degeneration of the liver.

Water Quality: Unrivaled robustness but requires rock-hard waters. pH 7.5 - 8.5, GH from 10 up to over 25, with tolerance for warm temperatures (22-30°C / 72-86°F). The collapse of the pH or soft and acidic waters are lethal in a short time.

Compatibility and Tankmates: Categorically discard slow or long-finned fish (Guppies, Bettas, Angelfish), which would be skinned alive. If absolutely necessary, pair only with armored Central American rock cichlids or very fast large cyprinids. Better monospecific tank.

Aquarium Reproduction: True viviparous (not ovoviviparous). The embryos are nourished directly by the mother through structures similar to an umbilical cord (trophotaeniae). Gestation lasts about 6-8 weeks and the pups (10-30) are born giant (almost 2 cm) and perfectly independent.

Risks and Diseases: Keeping and reproducing this species in the aquarium is a project of pure conservation, given the desperate situation in nature. They are subject to external parasitosis (Ich) if kept in too soft waters. Require vigorous oxygenation.