Description

Vietnamese Cardinal Minnow:

An Aquarium Guide

Vietnamese cardinal minnow (Tanichthys micagemmae) is a small, vibrant fish from the fast-flowing streams and rivers of Vietnam. Closely related to the more well-known white cloud mountain minnow, this species is prized for its intense red colouration and active shoaling behaviour.

Key Characteristics

• Size: Vietnamese cardinal minnow is a true nano species, growing to a maximum of around 2 cm (just under 1 inch).
• Appearance: They have a sleek, torpedo-shaped body with a bright, iridescent sheen. The most striking feature is a horizontal black line running from the gills to the tail, with a beautiful crimson-red stripe directly above it. The fins are often tipped with red.
• Temperament: This is a peaceful and non-aggressive fish. They are very active and spend most of their time in the mid-water column, especially when kept in a proper shoal.

Care and Habitat

Providing the right environment is essential for these fish to thrive and show their best colours.

• Tank Size: A tank of 40 litres (10 gallons) or more is suitable for a small group. A larger tank is always better to provide ample swimming space and greater water stability.
• Water Parameters: They are quite hardy and can tolerate a range of water conditions, but they prefer cooler temperatures.
  • Temperature: $18-24°C$ ($64-75°F$)
  • pH: $6.0-7.5$
  • Hardness: $2-15$ dGH
• Tank Setup: A well-planted aquarium with some open swimming areas is ideal. Use a dark substrate to make their colours stand out. They appreciate some water flow, mimicking their natural habitat in fast-moving streams.

Diet

Vietnamese cardinal minnows are omnivores with small mouths. They are not picky eaters but require a varied diet.

• Staple Diet: A high-quality micro-pellet or flake food should be a regular part of their diet.
• Live/Frozen Foods: Supplement their diet with small, live or frozen foods such as baby brine shrimp, daphnia, and microworms. This variety will keep them healthy and active.

Behaviour and Tank Mates

These minnows are a shoaling species and absolutely must be kept in a group.

• Social Structure: A shoal of at least 8-10 individuals will make them feel secure and bring out their natural shoaling behaviour. When kept in small numbers, they can become shy and stressed.
• Suitable Tank Mates: Due to their small size and peaceful nature, they are best kept with other peaceful, nano-sized fish. Good tank mates include:
  • Corydoras
  • Otocinclus catfish
  • Small Rasboras
  • Small shrimp (e.g., Amano shrimp)

Breeding

Breeding Vietnamese cardinal minnows in a home aquarium is straightforward.

• Spawning: They are egg scatterers and do not care for their young. A breeding tank with a spawning mop or java moss is recommended. The eggs will be scattered over the plants.
• Rearing the Fry: The eggs typically hatch within 2-3 days. The fry are tiny and will need to be fed infusoria for the first few days, followed by newly hatched brine shrimp.

Would you like to know more about keeping different types of minnows or perhaps building a nano aquarium setup?