Because I seem to have lots of success breeding Julidochromis dickfeldi, it should come as no surprise that I have a lot to write about them. In a previous post where I described some observations of the species, I indicated that the female was twice the size as the male. I should point out a couple of things about that statement. One, I have not removed any of my adult pairs to vent them. Two, the species profile on the Cichlid Room Companion states that dickfeldi exhibit sexual dimorphism in size – the male being larger than the female. Ad Konings’ dickfeldi description in Tanganyika Cichlids in Their Natural Habitat (4th Ed.) does little to shed light on the subject. However, he states that female J. marlieri and J. regani are almost always larger than males, and that female J. ornatus and J. transcriptus may be as well. I can’t say for certain which is typically larger, the male or the female. Nonetheless, males and females in a dickfeldi breeding pair are not the same size.
One of my breeding dickfeldi pairs resides in a 20g long. This pair has produced at least five broods. They spawn in a square ceramic tube that is 5″ long, closed on one end, with a 1.5″ opening in the other partially blocked off with a rock. Basically, it’s a cave. In all of those broods, what I consider the female patrols outside the cave once eggs are laid and fertilized. She allows nothing to get close to the cave opening. The male spends most of the time inside the cave when there are eggs or wrigglers, except to come out to eat.
An interesting behavior that Konings points out in his book is that eggs may be fertilized by multiple males. He also states the egg/brood guardian may be either the male or female, or in the case of polyandry, one of the two males may assume primary care duty. In fact, polyandry is not uncommon among Julidochromis species. Interestingly, one of the pairs’ offspring from an early brood is allowed in the cave. I was surprised to witness this, as what I presume to be another male seems to randomly enter and exit the cave without prejudice from the other two adults.
I was aware that some species of cichlids employ family “helpers” to protect juveniles and fry. I was not aware this applied to the Julidochromis genus. However, this was one of the first genus of cichlids where helpers were documented, which was more than 50 years. There are plenty of sources available to learn more about this. Below are a couple.
Reference: Sefc, Kristina M. (2011). Mating and Parental Care in Lake Tanganyika’s Cichlids. International Journal of Evolutionary Biology. doi:10.4061/2011/470875
Reference: Barlow, George w. (2010). The Cichlid Fishes. Perseus Publishing, Cambridge, MA.