convicts cichlids

Confused convicts cichlids in the confines of an aquarium, the inability of the fry to move beyond the parent’s reach typically results in their dissappearence as they are killed and eaten instead of being protected. this is true for many species, including the convict cichlid, Archocentrus nigrofasciatus.

Q: I have a pair of confused convict cichlids (Archocentrus nigrofasciatus) that have spawned eight times over the past six months. To most aquarists, this would seem great. My problem is that I can’t seem to grow the fry to any size. The parents initially protect their fry with violent attacks on the tank’s other fish. Then, in a few weeks time, the female gets ready to breed again. I can tell that i she is getting ready to spawn because her colors brighten and she gets a pinkish-orange patch on her belly. Once they reach this point, the parents eat all their earlier fry, then spawn again. Is it natural for convicts to eat their young fry to make room for a new brood? How can I manage to limit the female’s fertility and grow some of the fry to a reasonable size? Alex Erkine, New Jersey

A: To address your last query first, short of placing male and female in separate tanks out of one another’s sight. I know of no surefire method of preventing convict cichlids from spawning! As long as the fish can see one another, the female will go through the motions, even if the two sexes are housed in adjacent tanks. That no fry will result from the exercise clearly doesn t keep them from trying. Such determination is certainly one of the reasons that the convict cichlid enjoys the most extensive natural range and the widest commercial availability of any Central American cichlid.

The behavior you have described is not natural, in the sense that you would not observe it in the wild. It is, however, easily understood once you have a grasp of the problems a pair of cichlids must overcome to pull off a successful spawning in nature. Parental cichlids are effectively prevented from foraging normally for food by the constant effort expended in keeping predators away from their free-swimming fry. During the initial two to three weeks of the custodial interval, which can last as long as eight weeks, the parents survive by drawing on their reserves of body fat.

As the fry grow larger and the risk of predation upon them diminishes some-what, the adults again begin feeding, albeit on an opportunistic basis. The Demands parenting places upon her fat reserves and her inability to forage normally make it impossible for a broodtending female cichlid to yolk up another batch of eggs. The upshot of this is quite simple: in nature, pairs of cichlids do not respawn in the presence of dependent young. The situation in captivity is quite different. First of all, most parental cichlids need expend very little energy defending their progeny, their keeper having removed most, if not all, potential fry predators from the breeding tank. Secondly thanks to his or her diligent attentions, parental cichlids have daily access to as much high-quality food as they can eat.

There are thus no bioenergetic constraints put upon a female maturing a new batch of eggs within a few weeks of having spawned, well before the pair’s initial brood of young can survive without parental protection. Once this has taken place, a shift in her hormonal balance causes a shift from custodial behavior to pre-spawning behavior. Once this shift has occurred, she will react to the mobile fry exactly as she would towards any other fish large enough to pose a threat to a clutch of eggs or wrigglers. Under ideal circumstances, both male and female will manifest the normal reaction of a pair of cichlids to such a threat and try to chase the intruders out of their territory. In the confines of an aquarium, the inability of the fry to move beyond the pair’s reach typically results in their disappearance as they are killed and eaten by their erstwhile protectors. Under less than ideal circumstances, their parents are not of like mind with regard to the status of the fry.

This can result in serious intersexual fighting as one of the adults continues to defend the fry against the other’s efforts to expel them from the pair’s territory. The only way to prevent premature respawning is to slow down the rate at which a female matures a new batch of eggs. As it is virtually impossible to feed the fry without also feeding their parents, the most obvious solution, that of reduc-ing the adults’ intake of food to a level comparable to that existing in nature, is not a workable option. What does work reasonably well is to gradually reduce the water temperature in the breeding tank to 70 to 72 degrees Fahrenheit once the fry are free-swimming.

This will slow their growth, but it will also slow the metabolic rate of the adults and in so doing significantly extend the interval required for the female to mature another batch of eggs. If you turn the thermostat setting down a few notches in your tank, I’m certain you’ll have no difficulty raising the next batch of fry your pair produces to full independence.