by R. Shane Linder
The pearl danio is, to me, the prettiest of all common, small danios. The fish is an overall blue-silver with a reflective pinkish-red mid-lateral stripe that runs from just behind the belly to the caudal peduncle. This fish is fairly common in pet stores, and can be purchased at very reasonable prices. The pearl danio has a wide distribution from India throughout Southeast Asia. The fish is fine in temperatures from 68 F to 80 F and will thrive in almost any water chemistry, provided great extremes are avoided. Like most danios, the fish spends its days dashing about at the water surface and ignores other tankmates and plants. All in all, a very community tank-friendly fish.
I placed two males and three females in a 20-gallon tank to condition them. All five fish were 1.5" to 1.75" long, which is not quite full-grown. The fish were fed mainly dry foods with frozen foods 2-3 times per week. The conditioning tank was unheated and the temperature stayed around 72 F, the pH was 7.6, and the general hardness was at 150 ppm. On the evening of 14 January 1999, all five fish were transferred to a ten-gallon spawning tank. The tank was filled halfway and contained lots of Java Moss and a sponge filter. The tank’s chemistry was pH 6.8, temperature 80 F, and the hardness was 40 ppm. The fish spawned through the early morning and were removed at noon on 15 January. I did not witness the actual spawning.
The fry started hatching after about 60 hours, however, they lay on the bottom, absorbing their yolk sac for 4-5 days. First foods were Liquifry and what I call "sponge food". Basically, once or twice a day, I grab a sponge from another sponge filter in my fish room and squeeze the sponge into the fry tank. The fry attack the cloud, eating all the tiny organisms dislodged from the sponge.
After about a week, I got around to hatching some brine shrimp and fed these to the fry along with Tetra Bits, dry food smashed into a paste with a mortar and pestle. The fry have grown quickly, and one month later are basically clear, with a pink stripe running from the eye to the caudal. The largest fry are almost a half-inch while the smaller fry are about a quarter inch. As the fry grew, they were spread between two 10 gallons, a 20 long and a 5 gallon tank. Admittedly, with this many fry, I have not been very diligent about their care as I could not possibly care for this many fry. My best guess, though, is that, despite my inattention, I have about 200 to 300 fry between all four tanks. I plan to keep about 50 and place the large school in my 55-gallon display tank. It should be quite a sight.
This article first appeared in PVAS’s Delta Tale, Vol 30, # 2-3