The first description of Devario aequipinnatus was done by McClelland in 1839. During this first description, however, this species received the name Perilampus aequipinnatus. Currently, this original name is seen as a synonym of Devario aequipinnatus. Over the course of time, several other synonyms have emerged, namely: Devario cyanotaenia, Leucisus lineolatus and Perilampus ostreographus. Currently, scientists are still discussing the possibility that Devario aequipinnatus is a synonym of Danio aequipinnatus.
Devario aequipinnatus has a streamlined body which has a blue to green coloration. On the body a pattern can be seen of yellow stripes and spots. The finns are yellow to colourless.
The different sexes can be separated by looking at the size of the fish. Males are smaller and more colourful than females. This distinction becomes more clear when the fish are ready to mate.
Distribution and habitat
The range in which Devario aequipinnatus lives is relatively large. It is not only found in India and Nepal, but also inhibits waters in Cambodia, Vietnam, Thailand and Laos. Here it is found in water with a medium current. The rivers where specimens of Devario aequipinnatus live have clear water. The substrate of these streams, mainly consists of gravel and rocks. While aquatic plants are rarely found, overhanging foliage from terrestrial vegetation provides shade and coverage.
Several studies have shown that Devario aequipinnatus can cope with a high amount of different water parameters. Especially the water temperature varies between different rivers. For instance, a study at the Paisuni river recorded a water temperature of 32°C. Meanwhile, in the Bhadra river, temperatures ranged between 19 °C and 20 °C. The temperatures do not only vary between different locations, research at the river Siyom found that the temperatures fluctuated depending on the season as well. Measurements during the winter showed a temperature of 9 °C to 11 °C, while in the summer a temperature of 20 °C to 26 °C was measured. Overall, a temperature of 19-25 °C is recommended for in an aquarium. Since most people keep their water temperature constant throughout the year, setting the temperature too high or too low will have negative effects on the health of the fish.
Studies from the before mentioned rivers found that the pH fluctuated between 6,5 and 7. The GH will range between 0,5 and 1,6.
The natural diet of Devario aequipinnatus mainly consists of terrestrial insects such as mosquitoes. Despite their mainly carnivorous diet, debris from plants and algae are eaten as well.
In an aquarium, this diet can be created by giving mainly carnivorous foods with some plant matter as a supplementary part of their menu. This give the option to create a large deal of variation in their menu. One should, however, be careful not to feed to little carnivorous foods. These types of food should, namely, be the main part of their diet.
Devario aequipinnatus prevers an aquarium with a substrate of pebbles and gravel. While decoration should be present in the vorm of rocks and driftwood, aquatic plants are not a requirement. While the fish do not like a strong water flow in the aquarium, some current should be present. While the fish can survive a large range of different water temperatures, the temperature in the aquarium should be set between 19 and 25°C. A lid should be placed on the aquarium in order to prevent the fish from jumping out of the aquarium.
Devario aequipinnatus is a peaceful species that should be kept in a school. It will not harm fish from their own species nor from other species. Do make sure that they are kept with enough specimens.
Devario aequipinnatus can be seen breeding in community tanks. However, if one wants to increase their yield, a breeding tank should be set up. In this breeding tank, precautions can be taken to prevent the eggs and fry to be eaten. This can be done in several ways. For instance, plants with very fine leaves, such as mosses, could be planted. Moreover, specially crafted mops for breeding could be placed in the aquarium. In addition, a grid could be placed above the substrate. The eggs can fall through the grid but so the adult fish cannot reach them. At last, the substrate could be replaced by marbles. The eggs can fall between the marbles, preventing the adults to feed on them.
For breeding the fish successfully, the tank should have the ideal water parameters. In order to do so, pH will need to be set at 6,7. Nitrate, nitrite and ammonia should not be present at all. Water hardness should be between 3,6 and 4,2 °DH (60-70 mg/l). The water conductivity should range between 0 and 0,3 mS. 7,5 to 8,5 mg/l oxygen should be present in the water with an alkalinity of 30-35 mg/l. Water temperature should be set between 24,5 and 25,5 °C.
When the aquarium is set up, the fish can be placed in the tank. After doing so, the temperature should be raised from 25 °C to 27 °C. Increasing the watertemperature should be done slowly in 48 hours. 48 hours after the water temperature reaches 27 °C, about three quarters of all the water in the tank will be removed. At night, the tank can be topped up again with slightly cooler water (4 °C less than the current temperature of the tank). This will simulate the monsoon. To mimic the rain as well as possible, the water is ideally added to the tank using a sprinkler or a watering can.
The next morning, just after the aquarium lights have turned on, the fish will start spawning. The mating rituals may look aggressive. Males will chase females and fush their heads against the belly of the females. During this ritual, the eggs will be deposited in batches of 10 to 15 eggs. Of these eggs 75% to 90% will be fertilized. About 36 hours after mating, the eggs will hatch. At this moment, the fry is very small with a length of 2,8 mm. However, after six days, they have already reached a length of 4,5 mm to 4,8 mm. At this point, the fry will be able to swim freely throughout the aquarium. As from now, the fry will need to be fed. Due to their small size, the food should be very fine as well. Later, when the fish have grown to a larger size, bigger foods can be provided.
- Bagra, K., & Das, D. N. (2010). Fish Diversity of River Siyom of Arunachal Pradesh India: A Case Study. Our nature, 8(1), 164-169.
- Devario aequipinnatus . (n.d.). Retrieved February 20, 2018, from http://www.iucnredlist.org/details/166459/0
- Dey, S., Ramanujam, S. N., & Mahapatra, B. K. (2014). Breeding and development of ornamental hill stream fish Devario aequipinnatus (McClelland) in captivity. International Journal of Fisheries and Aquatic Studies, 1(4), 01-07.
- McClure, M. M., McIntyre, P. B., & McCune, A. R. (2006). Notes on the natural diet and habitat of eight danionin fishes, including the zebrafish Danio rerio. Journal of Fish Biology, 69(2), 553-570.
- Shahnawaz, A., Venkateshwarlu, M., Somashekar, D. S., & Santosh, K. (2010). Fish diversity with relation to water quality of Bhadra River of Western Ghats (India). Environmental monitoring and Assessment, 161(1-4), 83-91.