Rainbow Cichlid

The rainbow cichlid takes its name from the color changes it goes through during the day and in the breeding season. Normally its yellow-gold body has a dark band or a row of blotches along the middle; its fins are reddish orange. During breeding the lower half of the body and the fins turn coal black, while the upper half shines like gold.

It is the only species in the genus Herotilapia. The "tilapia" resemblance in its name comes from its three-pointed teeth, suited to nibbling plants and algae; "multispinosa" refers to the many spines in its dorsal fin. It is one of the mildest Central American cichlids and can comfortably be kept as a pair in a 150-liter aquarium.

It lives in lakes, wetlands and slow-flowing rivers on both the Atlantic and Pacific slopes of Honduras, Nicaragua and Costa Rica. Along muddy, shallow, densely vegetated shores it feeds on algae, plant fragments and small invertebrates.

• Volume: At least 150 liters and 100 cm of length for a pair.
• Decor: Stones, roots and caves. It nibbles soft plants; tough species such as Anubias, Java fern and Cryptocoryne hold up better.
• Substrate: Sand; it digs lightly in the substrate.
• Water: It adapts to a wide range of values; a 25–30% water change every week.

Omnivorous with a leaning toward plants. Use a spirulina-based granule or flake as the staple; give blanched spinach, zucchini and peas. Add protein with frozen bloodworms, brine shrimp and mysis. It also grazes on the algae in the tank.

Calm and curious in everyday life. During breeding the pair determinedly defends its spawning site, but its aggression never reaches the level of a convict or a Jack Dempsey.

Good companions: Firemouths, Thorichthys species, blue acaras, large livebearers, medium to large barbs and tetras, plecos.

Avoid: Large and aggressive cichlids, very small shrimp, valuable soft plants.

Kept as a pair. If juveniles are raised together, they pair up easily. Two pairs can be housed in a divided tank of 250 liters or more.

The pair lays a few hundred eggs on a cleaned stone or inside a cave. The eggs hatch in 2–3 days, and the larvae are moved to dug-out pits. Both parents guard the fry for weeks, and during this time the black-gold breeding coloration is at its most striking. The fry are fed brine shrimp nauplii and powdered food.

Hardy. Fin rot and hole-in-the-head disease (HLLE) can occur in dirty water. Fish fed only meaty foods develop digestive problems.

The male is slightly larger; his dorsal and anal fins are longer and more pointed. The female is smaller and stockier. A reliable distinction is made by the papilla.