The electric blue Jack Dempsey is powder blue all over, broken by black spots and a red edge on the dorsal fin. Juveniles are blue from the start, and shops sometimes sell the small ones as powder blue Jack Dempseys. It suits a keeper with a little experience.
Did you know
Every electric blue Jack Dempsey in a shop was pulled from its own spawn as a fry. Harry Piken wrote up the breeding for Tropical Fish Hobbyist in 2008. He had to separate his blue fry at a quarter inch (6 mm).
Caring for the electric blue Jack Dempsey
Keep an electric blue Jack Dempsey singly or as a bonded pair in a tank of at least 55 gal (208 L). Give it a soft sand or fine gravel bed to dig, with caves and rockwork to claim. Skip loose plants, because it uproots anything not anchored well, and expect the decor to be rearranged.
Run the water at 72 to 82°F (22 to 28°C) with a pH of 6.0 to 7.5. A big cichlid eats a lot and fouls the water, so make weekly water changes and keep it clean. Young fish are the fragile stage, so buy stock raised past 3 in (8 cm). Feed quality pellets with frozen and live foods, such as bloodworms, earthworms and the odd shrimp.
The electric blue is mostly peaceful and milder than the standard Jack Dempsey, and it holds the middle of the water column. It can share a tank with sturdy, semi-aggressive species too large to eat. Keep it away from the standard Jack Dempsey and other pushy cichlids, which bully it.
Electric blue Jack Dempseys are substrate spawners that lay their eggs on a cleaned flat surface. Both parents guard the eggs and fry hard and drive off anything that comes near. Breeding them takes a little experience.
Breeders pair a blue with a carrier for about half blue fry, or two carriers for about a quarter. Blue to blue spawns give frail fry that rarely survive. The blue fry are weaker than their normal siblings, so separate them early or the siblings kill them.
Good to know
The electric blue Jack Dempsey shows its color only when it carries two copies of the blue trait. A blue bred to a standard Jack Dempsey gives fry of normal color that carry the gene, sold as blue gene Jack Dempseys. Bent spines and wasting turn up in badly bred stock, so the line is less hardy than the wild type.
In the wild
The electric blue Jack Dempsey first appeared in Argentina in 1985. Héctor Luzardo, a breeder there, raised the first blue fish from a pair of ordinary Jack Dempseys a friend had given him. A young pair was shown at a fish exhibition in Uruguay in 1986, and the line spread from there. Luzardo's own circle guessed that a jaguar cichlid cross had put the blue gene in. Some writers still call the fish a hybrid. A 2005 DNA test commissioned by the importer Jeff Rapps matched the mother's line to a plain Jack Dempsey. That settles nothing on the father's side, and no blue population exists in the wild.
From published sources
Tank mates
Each fish here is named as a tank mate for the electric blue Jack Dempsey by at least two published care guides. Aquarium Source recommends keeping it on its own instead. These pairings assume a tank of 130 gallons (500 liters) or more, with caves and broken sight lines.
Is an electric blue Jack Dempsey a different species from the Jack Dempsey?
No. An electric blue Jack Dempsey is a variety of the Jack Dempsey, Rocio octofasciata. It is kept the same way apart from adult size, where it reaches 7.9 in (20 cm) against 9.8 in (25 cm) and temperament.
Why is my electric blue Jack Dempsey smaller and shyer than a standard one?
That is the line. Every shop that stocks it lists it around 8 in (20 cm) and milder than the wild-colored fish, and keepers on the cichlid forums say the same. Slower growth is normal too, so a two year old blue can sit well behind a standard fish of the same age.
Why are electric blue Jack Dempsey fry so hard to raise?
The blue trait is recessive and the fish that show it are frail as fry. Blue to blue spawns rarely survive, so breeders cross a blue with a normal-looking carrier and pull the blue fry out early, because their normal siblings kill them.
What size tank does an electric blue Jack Dempsey need?
An electric blue Jack Dempsey needs at least 55 gal (208 L). It spends most of its time in the middle.
What does an electric blue Jack Dempsey eat?
An electric blue Jack Dempsey eats quality pellets, plus frozen and live foods such as bloodworms, earthworms and the odd shrimp.
How big does an electric blue Jack Dempsey get?
An adult electric blue Jack Dempsey reaches about 7.9 in (20 cm).
How does an electric blue Jack Dempsey breed?
An electric blue Jack Dempsey is a substrate spawner that lays its eggs on a cleaned flat surface. Both parents guard the eggs and fry hard, and breeding takes a little experience.
What fish can live with the electric blue Jack Dempsey?
7.9 in (20 cm)50 gal (190 L)72–82°F (22–28°C)
7.9 in (20 cm)106 gal (400 L)75–82°F (24–28°C)
7.9 in (20 cm)53 gal (200 L)75–82°F (24–28°C)
7.9 in (20 cm)79 gal (300 L)77–84°F (25–29°C)
7.9 in (20 cm)63 gal (240 L)75–82°F (24–28°C)