The Hikari Danio is truly a sensation though it has risen out of obscurity only in the past few years since its introduction in 2002/2003. It is newer species of danio discovered in Burma (Myanmar), Asia and is still awaiting its scientific name. It appears very similar to the Blue Danio Danio kerri. and was at first speculated to be a subspecies. However more recent DNA testing in the United States has shown them to be genetically distinct, so this species is currently known simply as Danio sp. "hikari".
Perhaps the crowning achievement of the Hikari Danio is that it is one of few freshwater fish whose sexes have distinctly different colors. The colors are different enough that the sexes are often erroneously referred to as separate species. They are sometimes referred to as the Hikari Yellow Danio and the Hikari Blue Danio, but these two fish are actually the same species.
The Hikari Yellow Danio is the male of this species and has a yellow tinge to the fins and body. The Hikari Blue Danio is the female and will be noticeably bluer in color. They are a small fish that will grow to just about 2 inches (5 cm) in an aquarium. These danios are not overly flashy, but can be just as impressive as the next fish. They can make a fun and lively display with the added benefit of having the mix of colors.
Like all danios they are robust, fairly easy to keep, and prolific breeders. They can adapt to a reasonable range of water temperatures and conditions. These qualities make them an excellent choice for both the beginner and the more experienced aquarist. They are schooling fish and should be kept in groups of 6 or more. A school of these small lively fish are well suited to a smaller aquarium, but will do best in about a 20 gallon size.
These cyprinids are a generally pleasant community fish. They can be housed with most similarly sized community fish that have similar behaviors. They will do well with other lively tank mates, just make sure that the danio will not be eaten and that the other fish aren’t startled by swift movement. They can also jump with surprising gusto so keep a tight covering on your aquarium.
The Hikari Danio Danio sp. "hikari" is native to Burma (Myanmar), Asia. These cyprinids are a more recent discovery and were introduced into the hobby in 2002/2003. They were first collected from the Tanintharyi River drainage, which is a tributary of the Tenasserim River system in southern Myanmar.
This fish doesn't have a scientific name at this time. It is currently known simply as Danio sp. "hikari". Initial speculation was that it could a subspecies of the Blue Danio Danio kerri, as these fish are very similar. However more recent DNA testing in the United States has shown them to be genetically distinct. It is not yet evaluated or listed on the IUCN Red List of Endangered Species.
Not a lot is known about this fish, but in nature it is suspected they inhabit the marginal zones of streams and small rivers. This is where the water is quiet and slow moving. Their main diet in the wild probably consists of small insects, worms and crustaceans.
Scientific Name: Danio sp. hikari
Social Grouping: Groups
IUCN Red List: NE - Not Evaluated or not listed
The attractive Hikari Danio has a rather compact body and there is a barbel at the end of each lip. These are small fish reaching lengths of about 2 inches (5 cm) in an aquarium. A typical lifepan would be about 3 - 5 years with proper care, and possibly longer.
These are one of the few freshwater fish whose sexes have distinctly different colors. This has led to the sexes often being erroneously referred to as separate species. The Hikari Yellow Danio is the male of this species and has a yellowish green tinge to the body and fins. The Hikari Blue Danio is the female and will be noticeably bluer in color.
Size of fish - inches: 2.0 inches (5.00 cm)
Lifespan: 5 years - An average lifespan would be about 3 - 5 years, though they could live longer with proper care.
Fish Keeping Difficulty
The Hikari Danios are fairly hardy fish and so are recommended for beginners. They readily accept many foods and adapt to most tank conditions. They will feed on just about anything that is offered, as long as it floats at the surface where they can readily consume it.
Aquarium Hardiness: Very Hardy
Aquarist Experience Level: Beginner
Foods and Feeding
Since they are omnivorous, these fish will eat most prepared or live aquarium fare, though the food does need to float at the surface. A good balance of food is necessary to keep this fish’s coloration strong. As with all danios, these fish are quite active and have high nutrient requirements, so select a flake food that will provide for their needs. These fish will do best when offered food several times a day, but offer what they can eat in 3 minutes or less at each feeding. If you feed only once per day, provide what they can eat in about 5 minutes.
Diet Type: Omnivore
Flake Food: Yes
Tablet Pellet: Yes
Live foods (fishes, shrimps, worms): Some of Diet
Vegetable Food: Some of Diet
Meaty Food: Some of Diet
Feeding Frequency: Several feedings per day - Offer only what they can consume in 3 minutes or less with multiple feedings per day.
These fish are not exceptionally difficult to care for, and mostly just need their water to be kept clean. At least 25 - 50% of the tank water should be replaced once a month. If the tank is densely stocked 20 - 25% should be replaced weekly or every other week. Aquariums are closed systems and regardless of size all need some maintenance. Over time decomposing organic matter, nitrates, and phosphate build up and the water hardness increases due to evaporation. Be mindful during maintenance that these fish will jump, so keep a close eye on them.
Water Changes: Monthly - It the tank is densely stocked the water changes should be done every other week.
Hikari Danios are little survivors and will readily adapt to your aquarium’s conditions, within reason. Though a school of danios can be kept in a smaller aquarium, they will do best in about a 20 gallon size. Provide good filtration for the aquarium. Some current will be appreciated by these fish as well. These fish can swim and jump with surprising gusto, so keep a tight covering on the tank.
These fish are most effectively displayed in tanks with subdued lighting and a dark colored fine gravel or sand substrate. They like a well planted aquariums and a variety of plants will make them feel safe. Dense tall plantings around the sides and back are great, but these fish prefer open water in the middle of the tank for swimming.
Minimum Tank Size: 15 gal (57 L) - Though a school can be kept in a smaller aquarium, they appreciate ample swimming space and will do best in about a 20 gallon size.
Suitable for Nano Tank: Yes
Substrate Type: Any
Lighting Needs: Moderate - normal lighting
Temperature: 68.0 to 80.0° F (20.0 to 26.7° C)
Range ph: 6.0-8.0
Hardness Range: 2 - 18 dGH
Water Movement: Moderate
Water Region: All - They will move about the tank a lot but will usually swim in the middle.
These fish have a good temperament, but they will sometimes go looking for trouble. Although generally peaceful the aquarist should not be surprised to witness small squabbles amongst these danios and possibly other tankmates. Hikari Danios will play amongst each other, and often wrongly assume that the other fish want to join in. Larger fish may be irritated by them and smaller fish may be frightened. This fish is very lively and active which might irritate fish that prefer a calm environment. Danios create an inherently fast paced environment which many fish may not tolerate, so select the tank mates well. The best tankmates are other similarly sized lively fish and bottom dwellers like plecostomus and loaches.
Temperament: Peaceful - They are generally peaceful fish but don't be surprised to witness small squabbles amongst these danios, and possibly with other tankmates.
Same species - conspecifics: Yes - They need a school of at least 6, though 8 to 10 is even better.
Peaceful fish (): Safe - This fish is very lively and active which might irritate fish that prefer a calm environment.
Semi-Aggressive (): Threat
Aggressive (): Threat
Large Semi-Aggressive (): Threat
Large Aggressive, Predatory (): Threat
Slow Swimmers & Eaters (): Safe - This fish is very lively and active which can stress fish with a calmer nature.
Shrimps, Crabs, Snails: Safe - not aggressive
Sex: Sexual differences
Hikari Danios are among the easiest fish to sex, the males will be distinctly yellow in color with turquoise patches. Females will be silvery blue with turquoise patches.
Breeding / Reproduction
Breeding the Hikari Danio is not difficult. They are egg scatterers and exhibit no parental care for the young. Two fish will form a breeding pair which they often keep for life. If you wish to retain the young, the breeding tank should be empty except for a two inch layer of large glass marbles, 1/2 to 1 inch in diameter. Add the female to the tank and let her settle for about a day before adding the male.
After they are both in the tank, and if conditions are favorable, the female will release her eggs in open water and the male will fertilize. The eggs will then sink to the bottom and fall through the marbles, out of their parents reach. The fry will emerge from there after about 7 days. At that time or before, parents should either be removed or kept constantly well fed. See the description of breeding techniques in: Breeding Freshwater Fish: Barbs. Also see Fish Food for Fry for information about types of foods for raising the young.
Ease of Breeding: Easy
Hikari Danios are fairly hardy and disease is not usually a problem in a well maintained aquarium. They are primarily susceptible to Ich if good water quality is not provided. With any additions to a tank such as new fish, plants, substrates, and decorations there is a risk of introducing disease. It's advisable to properly clean or quarantine anything that you want add to an established tank prior to introduction, so as not to upset the balance.
These fish are very resilient but knowing the signs of illness, and catching and treating them early makes a huge difference. An outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. The best way to proactively prevent disease is to give your fish the proper environment and a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish will is more likely to acquire disease. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
The Hikari Danio is being offered in more and more locations, but is as of yet rather uncommon. It may be found in pet stores and from internet or mail order, and is moderately inexpensive.