Julidochromis regani Breeding Guide
How to breed Julidochromis regani, a biparental cave-spawning Tanganyikan cichlid: pairing, sexing, spawning in caves and fry care.
Overview
Julidochromis regani is the largest member of its genus, a rock-dwelling cichlid endemic to Lake Tanganyika and recorded from Burundi, the Democratic Republic of the Congo, Tanzania and Zambia (Wikipedia). It is a secretive biparental substrate spawner that retreats to caves or rock crevices to breed (Wikipedia). Seriously Fish rates breeding as easy but notes that patience is required, mainly because obtaining a compatible pair can be slow.
Sexing
Sexual differences are subtle. According to Seriously Fish, the genital papilla of males is more extended and pointed than that of females, and adult females are also typically larger than males. Because reliable sexing of young fish is difficult, the recommended approach is to raise a group and allow a pair to form naturally.
Conditioning
Condition prospective breeders on a varied carnivore diet to bring them into spawning condition. Breeding is reported to occur at a pH of around 8.2-9.0 and a temperature of about 77-80 deg F (25-27 deg C), in line with the species' hard, alkaline Tanganyikan water (Seriously Fish).
Breeding Setup
Provide a rocky aquascape with multiple caves and crevices that the pair can defend as a spawning site. Once a pair forms - which Seriously Fish notes may take a year or more - the pair will remain together for life, so other fish are best removed from the breeding tank to reduce conflict (Seriously Fish).
Spawning Behavior & Trigger
The pair spawns very secretively inside a cave. Seriously Fish reports that the female lays up to 300 eggs (usually fewer), scattered on the wall or roof of the chosen cave. Large, abrupt water changes are best avoided around bonded pairs, as they can provoke aggression between mates.
Egg & Fry Care
Brood care is biparental: the female tends the eggs while the male guards the area around the cave (Seriously Fish). Parents may sometimes be seen leading their fry around the aquarium (Wikipedia). Fry are large enough to take brine shrimp nauplii almost immediately, and young can remain with the parents until they reach roughly 1 inch (2.5 cm), at which point they should be removed (Seriously Fish).
Common Challenges
The main difficulty is forming a compatible pair, which can take many months. Wikipedia notes that although partnerships are largely monogamous, polyandry has been documented in both wild and captive settings, so a settled pair should not be disturbed once breeding begins.