Enteromius hulstaerti – Butterfly Barb
Enteromius hulstaerti or Butterfly Barb in common English is a small fish of only 4 cm long that needs to be kept in a school. These fishes are a good addition to any tank, due to their extraordinary appearance. The fish have big black blotches on the side of their bodies. In addition the males have yellow fins with a black, horizontal bar across them. As females have no colors in their fins at all, this feature can be used to separate the males from the females.
Synonyms: Barbus hulstearti, Capoeta hulstearti, Puntius hulstearti.
Enteromius hulstaerti can be found in the Democratic Republic of Congo. These fish live in swamps or rivers with a very slow current. These waters tend to be very shaded, so bright lamps will not be the best option for the aquarium.
In order to give this small species enough space to swim you will need an aquarium of 60 centimetres (about 23 inch). However, a bigger tank would be preferred. The Enteromius hulstearti tends to be a very active species. As a consequence, they need to have enough open space to be able to swim. Do not forget to create enough hiding places as well. This can be done by placing plants and other decorations in certain places of the aquarium. As mentioned before, Enteromius hulstaerti prefer a dimmed lightning in the aquarium. Besides adding dim lights, floating plants could also be used.
Enteromius hulstearti need a temperature of 20 to 26 degrees Celsius (68 to 78 degrees Fahrenheit). For breeding these fishes, it is necessary to lower the temperature to 17 degrees Celsius (62 degrees Fahrenheit). The acidity should, ideally be between a pH of 5 and 6,5. The water hardness should not be too high. A GH of 3 and 6 would be recommended.
In its natural habitat Enteromius hulstaerti feed on small insect larvae and small crustaceans. In the aquarium you should this mimick this carnivore diet. They can be fed with live or frozen artemia, mosquito larvae and daphnia. Dried and factory food is accepted as well.
Enteromius hulstaerti is an active schooling fish. It will not attack other species and leave them alone. Towards their own species, males will show territorial behaviour. Since the Enteromius hulstaerti is a schooling fish, it should not be kept with less than 7 specimens. Furthermore, it is not a good idea to add them to a tank with large or aggressive species. Due to their small size they will be eaten. Furthermore, Enteromius hulstaerti will try to hide become very shy.
Breeding Enteromius hulstaerti is not very easy. The requirements for the water parameters are rather strict. In order to breed successfully, they can not be different than the parameters mentioned above. These fish have two mating seasons every year. These seasons are between March and June, and between September and November.
Of all water parameters temperature is the most important. The main experience is that when the eggs are incubating on a temperature of 22 degrees Celsius (71 degrees Fahrenheit), almost all fry will turn out to become males. In order to get an even distribution of males and females they need a temperature of 17 to 20 degrees Celsius (62-68 degrees Fahrenheit).
During the mating season, Enteromius hulstaerti will lay eggs between the leaves of plants. When all the eggs are fertilized, the parents need to be removed from the tank. 7 to 10 days after spawning, the eggs will start to hatch. During the first week the fry will be too small for artemia nauplia. So feed them with very fine grained dust food until they are large enough to handle the nauplia.
Choy Heng Wah
F. Ingemann Hansen – Akvariefotografen.com