Q. I am a relatively new aquarist with eight tanks of various sizes, and am extremely interested in breeding cichlids, especially Geophagus jurupari. I have three 2-inch to 3-inch specimens. However, I have been unable to sex them and it seems that everyone I consult is as unsure as I am. Can you give me any guidance on how to tell the sexes apart and how best to go about breeding one of my favorite cichlids?

A. Before I address the two questions you have asked, I must make the observation that the correct name for the fish you know as Geophagus jurupari (the genus name means "earth eater") is actually Satanoperca leucostictus. In his 1986 paper on the cichlid fishes of Peru, the Swedish ichthyologist Sven O. Kullander concluded that the genus Geophagus actually comprised several evolutionarily distinct lineages that had been grouped together on the basis of superficial similarities.

He therefore resurrected the generic name Satanoperca for the long-snouted, sexually similar appearing species formerly included in Geophagus (S. acuticeps, S. daemon, S. jurupari, S. leucostictus and S. pappaterra). His research also led to the conclusions that several quite distinct species have been confused with S. jurupari, and that the fish widely known to aquarists by that name is S. leucostictus, a look-alike native to the Guianas. The true S. jurupari lacks the bold metallic blue-green spangling of S. leucostictus. Specimens are sporadically exported from western Amazonian localities, such as Manaus and Iquitos. However, most of the "jurupari" offered for sale by most wholesalers are really more colorful, tank-reared S. leucostictus imported from the Far East.

Among Satanoperca leucostictus of the same age, males are usually somewhat larger than females, but apart from direct examination of the genital papillae, I know of no reliable way to sex these fish, including adults. At 2 to 3 inches, even this method is likely to give ambiguous results. If you are serious about breeding this species, I suggest you obtain three or four more specimens of the same size and raise the group together. This is the simplest and most reliable way to secure compatible pairs of any monogamous cichlid species. I also suggest you cultivate patience. Satanoperca species are slow to mature. Individuals rarely show any signs of sexual activity until they are two years old.

The secrets to breeding S. leucostictus are scrupulous attention to water quality and the fish's privacy. These "earth eaters" have a very low tolerance for dissolved metabolic wastes. They typically respond to poor water quality by developing the symptoms of "hole in the head" disease and then eventually succumb to systemic bacterial infections. Frequent partial water changes are absolutely essential to their well-being in captivity.

Spawning rarely occurs in a community setting because large adult size notwithstanding, Satanoperca species are not very assertive. They are easily bullied by smaller, more assertive cichlids, and under such circumstances simply cannot hold a breeding territory. If allowed their own quarters, pairs of these bi-parentally custodial primitive mouthbrooders will spawn regularly and usually prove to be excellent parents.