Last year I purchased 10 Diamond Tetras at a monthly DSAS auction. Joe Kaznica who had bred them had offered them at auction. Joe has a great knack breeding tetras and I know all his fish are well maintained. The sparkling appearance of these fish is what caught my eye and so I bid on them, but was not really prepared to house them when I got home. I had a 20-gallon long tank that had only a few young Corydoras panda in it, so I dumped the tetras in with them. I usually quarantine my newly acquired fish, but I have never had a problem with Joe’s fish so I felt secure in adding them to this tank.
Moenkhausia pittieri, the Diamond Tetra, hails from Lake Valencia in Venezuela. The male is about 2” in length and the female slightly smaller. The male’s dorsal fin is high and pointed whereas the female’s is smaller and blunt. Both sexes have the iridescent scales that give the fish its name, but the over all appearance of the male seems flashier and the female paler. The dorsal and anal fins have a very light lilac coloration. These guys really flash their stuff as they dart around the tank chasing each other.
The water the Diamond Tetras were in was soft, a pH of 6.8, and the temperature was 75 F. (24 C.). The tank was bare bottomed with a sponge filter. I had some clumps of Java moss in the corners and some duckweed floating on the surface. I use the duckweed mainly to keep the light intensity in the tank low. These must have been good parameters for the tetras because they acclimated to it with no discernable problems. Within a couple of hours they were cavorting all over the tank. They were already picking at the Hikari sinking wafers that I use to feed my catfish.
About a two weeks later I noticed some of the females were a little plumper and there was a pinkish glow to their bellies. I figured they may be gravid since the males were a bit more aggressive in chasing them. I moved a male and the most gravid female to a 5-gallon tank with water from the original tank and a sponge filter. I placed a green nylon spawning mop in the tank along with a clump of Java moss and raised the temperature to 80F (27C.). I had read that Diamonds prefer that temperature for spawning. Each morning I checked the mop and Java moss for eggs. On the fifth day I found some eggs in the moss. I remove the parents to a 55-gallon community tank.
The eggs were extremely small (1mm) and had a pale amber-yellow coloration. I lowered the water level to about 2” depth to make it easier for the future fry to find food. They hatched out sometime on the second day. Most of the fry stayed in the Java moss but a few were on the bottom of the tank. These babies were very small, clear in color, and thin. In fact if it wasn’t for their yolk sac and their dark eyes I doubt I would have seen them. Since they still had a yolk sac I did not add any food to the tank. Besides I felt there was plenty of micro-organisms in that well-aged water and on the moss to sustain the fry initially.
When the fry were free swimming, 4-5 days, I began adding some APR but soon the fry were accepting both newly hatched brine shrimp and finely ground flakes. The fry grew fairly rapidly on this diet and I stopped the brine shrimp after two weeks. The young fry were silvery in appearance but showed no signs of the iridescence of the adults. They also did not have the depth of body and intricate finnage of the adults. Those traits developed as they matured.