- Scientific name: Tanichthys micagemmae
- Synonyms: -
- Common name: Vietnamese Minnow, Dwarf Vietnamese Cardinal
- Group: Cyprinids
- Habitat: Southeast Asia; Vietnam
- Size: 2-3 cm
- Biotope: Endemic to the Ben Hai River drainage in north central Vietnam, which is a fast-flowing, shallow stream with sandy substrate and measured around 15 metres across. The fish found usually in shallow, quieter areas along the shores.
- Social behavior: A very peaceful, schooling species, which can be kept with other fish, prefering similar conditions.
- Diet: Omnivorous; In nature they feed on small insects, worms, and zooplankton. In the aquarium they can be fed with live, frozen and flake foods, and also accepts some vegetable matter.
- Breeding: Easy
- Tank: Minimum 40 litres
- Population: 6-8 fish for 40 litres
- Decoration: They deserve a heavily-planted tank, with dark substrate. Decorate the tank with some floating plants and driftwood roots. They need moderate water-flow and will also do well in a hill stream-type set-up.
- Temperature: 18-23 °C
- pH: 6.5-7.5
- Hardness: 2-8 NK°
- Lifespan: 3-5 years
Description: Tanichthys micagemmae only became available in the aquarium hobby in the early 2000 years, and its popularity still unbroken since it’s attractive, easy to keep and breed and usually quite cheap. In the Dwarf Vietnamese Cardinal the ventral and anal fins are reddish. The head and the body below lateral midline is whitish with many small dark grey spots. There is one black and one white longitudinal stripe of about the same width on its body. The distance from dorsal-fin origin to upper margin of whitish stripe about equal to distance from anal-fin origin to lower margin of black stripe. Reports indicate that it may soon be extinct in the wild, because of the rapid growth of the ornamental fish trade from Vietnam, and the rapid urban growth and habitat destruction.
It is hard to tell apart the sexes when juveniles, but mature females are usually rounder-bellied and often a little larger than males. Males usually intensify in color when in spawning condition, and may develop extended dorsal and anal fins with age. Like most small cyprinids Vietnamese Minnow is also an egg-scatterer fish, exhibiting no parental care. Well-fed fish will usually spawn, and it is possible that a small numbers of fry will survive in the community tank, however if you want to save more fry, a separated aquarium is required. They can be bred in a small, dimly lighted tank, that filled with Java moss, or the base covered with some kind of mesh that large enough grade so the eggs can fall through, but small enough to the adults cannot reach them. The water should be slightly acidic, with a temperature of 23-24 °C. Condition the adult fish for a couple of days with live foods, and place them into the breeding tank, where they will usually beed in the following morning. The parents should be removed after spawning, as they will eat the eggs. The eggs hatch in 48-72 hours and the fry should be fed with microscopic food once they can be seen swimming freely.