Danio kerri – Blue Danio
Smith was in 1931 the first to describe Danio kerri. He gave the name “kerri” to this species as a reference to Dr A.F.G. Kerr. Smith did this as Dr. Kerr was the first person to catch this species. Kerr caught them already in 1925.
Synonym: Brachydanio kerri.
The coloration of the Danio kerri is greenish blue. At the middle of the body two horizontal lines run from the head to the tail. These lines have are orange and reflect light. The belly of the fish is white.
Difference between the sexes is rather difficult to see. The distinction, however, gets more clear when the fish are ready to mate. In this case males will have their coloration at their best while the colours of females tend to be a bit dull. Furthermore, will the bellies of the females become even rounder than normal.
Distribution and Habitat
This species is originally found on the island Ko Yao Yai, which is part of Thailand. Nowadays, Danio kerri is also known from other islands such as: Phuket, Ko lanta and Langkawi. To add to that, have there also been sightings on the mainland of Thailand.
It is noticeable that the exact coloration of the fish will differ depending on the location the specimen is caught. Populations that are found to the north tend to be more blue colored. However, southern populations are almost yellow.
Danio kerri is generally found in small rivers with very clear water. As there are no plants to be found in the water, the fish tend to swim between rocks and pieces of wood. The rocks in these rivers are covered with a biofilm.
This specie has mainly a carnivore diet. In the wild Danio kerri will eat small crustaceans and insect larvae. At home, in the aquarium it is not such a picky eater. It will accept almost all types of food. So there is no need to feed only frozen or live foods. It is to be noticed, however, that carnivorous food is recommended for the health of the fish.
Danio kerri is relatively easy to keep in the aquarium. There are no special demands for water chemistry. Moreover, is this type of danio rather peaceful. It is recommended that you place a shoal that is large enough in your tank. Generally, the more the better. If the shoal becomes larger, the fish will show more interesting behaviour.
Danio kerri Reproduction
If the Danio kerri is in a good shape, it will even spawn in a community tank. However, in these tanks most eggs and fry will be eaten before they reach adulthood. To increase the yield, it is necessary to set up a separate tank for breeding purposes. This tank should be filled with suitable spawning media. For instance Javamoss or wool mops can be used. Another solution can be to place marbles at the bottom of the tank. Eggs will fall between the marbles so the parents cannot eat them.
The tank itself should be filled untill it is half full. By the time the fish are placed inside the tank you could start filling it up. This should be done slowly with cooler water. This mimics the conditions during the rainy season and brings the fish in the mood to mate. As soon as the parents have leid their eggs, they should be removed from the tank. 24 to 36 hours later the eggs will hatch. A couple of days later the fry will be ready to swim freely in the tank. As soon as the fry starts to swim, they can be fed with artemia nauplii.
Nonn Panitvong – Siamensis.org