Factsheet 18

Glossolepis dorityi. Allen 2001¹

This is a new species of Rainbow fish that has only recently become available in the U.K., having been well established in Germany. Not as colourful as some of the other members of the genus, nevertheless, the male fish have many subtle colours which show beautifully, particularly when the fish is in sunlight.

The species derive from Papua and has only been found in one location. According to Gerald Allen, they are found at the outlet of a small lake in a fast flowing stream. The vegetation is very dense around the outlet.

When purchased, the pair was quarantined in a small tank with plenty of cover. As with most fish, once they had settled down they were ravenous. A large amount of bloodworm was consumed with relish. They are now eating tubifex, dried foods and most frozen foods. After two weeks, they were transferred to an 18 x 12 x 12 inch tank. Some of the water used in the quarantine tank was used to supplement fresh water. Two spawning mops were added and it was only a matter of a couple of days before eggs started to appear. Nearly all the eggs laid, were at the very ends of the mops. After four days, there were signs of developing embryos. Meanwhile… in the tank they had been quarantined in, they had also laid eggs and these hatched after about 8 days. The first signs being a couple of fry swimming around looking for food. Glad I did not clean the tank out! I decided to use the ZM Systems new (to me) ZM-000 grade fry food on these typically very small fry. This grade of food is a very fine powder rated at between 30 and 50 microns.

Initially, I added some to a small amount of tank water in a small test tube; shook it vigorously and then added it to the fry tank. This was really unnecessary as the rainbow fry are always to be found at the surface of the water so a little food added, very quickly disperses right across the surface. After just a few days, the fry were visibly growing. By the end of two weeks, they had well over doubled in size. As they grew, I went up the grades of food and found they continued to progress well. Their diet was also supplemented with newly hatched brine shrimp. There then followed the usual progression of chopped tubifex etc. As with all rainbows, they are not particularly fast growing fish, but with time, space and good food, will make good sized specimens.

P.S. What is a Micron? It is a unit of measurement being ONE, one thousandth of a millimetre. Just to put it into perspective, a human hair has a diameter of around 90 microns.

   1. Allen. G.R. A New Species of Rainbow fish (Glossolepis:Melanotaeniidae) from Iran jaya. Fishes of Sahul 15(3) 776-775

© Pete Cottle, 2004. This fact sheet may not be reproduced in any form without the permission of the author.