River Loaches (Balitoridae)

Annamia Loach

Annamia thuathienensis

Annamia thuathienensis, also known as the Annamia Thua Thien Loach, belongs to the family Balitoridae, which comprises river loaches. Its name reflects its geographical origin: Annam is the historical name for central Vietnam, and Thua Thien is a modern province. This species is not suitable for a general community aquarium, as it requires specific keeping conditions. This fish is mainly found in Asia, and it is practically impossible to find it in European markets.

Tank
from 108 L (29 gal), 110 L (29 gal) recommended
Temperature
16 – 22 °C (61 – 72 °F)
Size in aquarium
8 – 10 cm (3.1 – 3.9 in)
Acidity
pH 6–7.5
Natural rangeRange on the map
  • Thừa Thiên-Huế Province area
  • Annamite Range area
  • Vietnam

Tank conditions

Plan the tank stocking
Temperature
16 – 22 °C (61 – 72 °F)
Water pH
Slightly acidic (6) – Neutral (7.5)
Water dH
Very soft (1) – Medium hardness (10)
Water salinity
no salt (freshwater)
Size in aquarium
8 – 10 cm (3.1 – 3.9 in)
Lifespan
8 years
Temperament
Peaceful (regular)
Toward small fish
not a predator
Required aquarium volume
from 108 L (29 gal), 110 L (29 gal) recommended
Lighting
bright
Substrate
rocky rock formations, boulders, etc.
Water flow
moderate or strong
Feeding
Meat / protein live, frozen, fresh
Keeping
Medium group 6–8 individuals
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. The 108 L minimum corresponds to a tank footprint of 120×30 см. The recommended 110 L is for the group size given under keeping mode.

Care and keeping

Description

Adults of this fish reach a length of 8–10 cm. Their body is elongated and somewhat flattened from above. This body shape helps them successfully withstand fast currents. Large, fan-shaped fins also contribute to this, allowing the fish to cling firmly to the smooth surfaces of rocks. Their coloration is predominantly gray with noticeable golden hues. Sexual dimorphism is weakly expressed, making sex determination difficult. The Annamia Thua Thien Loach bears an external resemblance to its close relative, Annamia normani, which often leads to confusion between the two species.

Habitat

Its natural habitat is Southeast Asia, specifically the territories of modern Vietnam. The Annamia Thua Thien Loach inhabits shallow rivers and streams, numerous flows of which descend from the Annamite Mountains. The natural conditions of these bodies of water include rapids, creating a fast, in places very turbulent current. The water there is clear and clean, and vegetation grows mainly along the banks. The bottom is typically rocky, with large boulders.

Behavior and Compatibility

Although this species is peaceful and calm, its specific requirements for keeping conditions impose certain restrictions on the choice of tankmates. These fish should be kept in a group of at least 6–8 individuals. Small skirmishes between conspecifics are possible, but this is part of their social behavior and does not pose a threat to other fish.

Care and Maintenance

For a group of 6–8 fish, an aquarium of at least 110–120 liters is recommended. It is crucial to create conditions that are as close as possible to their natural habitat. A rocky substrate with several large boulders and snags is suitable for decoration. Water movement is provided by a powerful filtration system and/or a special system for creating an artificial current, which can be made independently. Live plants are not essential, as they do not thrive in strong currents and relatively low temperatures. Unpretentious mosses and ferns attached to snags are acceptable. Like most inhabitants of flowing waters, Annamia thuathienensis is sensitive to organic waste and requires oxygen-rich water. Regular aquarium maintenance includes cleaning the substrate and glass, partial water changes (30–50% of the total volume) with fresh water, and maintaining stable pH and dGH parameters. An additional aeration system will also be beneficial.

Diet

The diet should include protein-rich foods, such as live or frozen foods like bloodworms, daphnia, and brine shrimp. It is also important to include plant-based supplements, such as spirulina flakes. Algae that form on various decorative elements in the aquarium can serve as a natural dietary supplement. Dry foods, including flakes, granules, and tablets, are used in limited quantities as a source of essential trace elements and vitamins.

Breeding and Reproduction

To date, there are no documented cases of successful breeding of Annamia normani in home aquariums. Fry intended for the aquarium trade are typically caught directly from the wild.

Diseases

Non-ornamental fish species that have retained a close resemblance to their wild relatives usually exhibit high endurance, strong immunity, and resistance to various diseases. The occurrence of health problems most often indicates unsuitable keeping conditions. Therefore, before proceeding with treatment, it is strongly recommended to check the water quality and parameters. Only after all indicators have been brought back to normal should treatment begin, if it is still necessary.

How to choose

When purchasing Annamia loaches, special vigilance should be exercised regarding the health of the specimens, as this species often arrives emaciated. A critically important sign is the absence of pronounced thinness, especially in the area between the pectoral and pelvic fins. A healthy fish should appear well-fed and active. — Avoid purchasing individuals with sunken bellies, as it can be extremely difficult to restore their condition at home; — Prefer fish that appear active and show no visible damage, ulcers, or signs of fungal infections on their bodies and fins; — Given the social nature of the species, it is recommended to acquire a group of 6–8 individuals, as when kept alone or in small groups, the fish become timid and stressed.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Annamia Loach get?

An adult reaches 8–10 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Annamia Loach need?

The recommended volume is 110 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Annamia Loach need?

Temperature 16–22 °C, pH 6–7.5, hardness 1–10 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Annamia Loach live?

Around 8 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Annamia Loach aggressive?

Temperament: peaceful (regular). Keep this in mind when choosing tank mates.

How many Annamia Loach should be kept together?

Recommended setup: medium group (6–8 individuals). Ignoring this is a common cause of stress and disease.

What does Annamia Loach eat?

Diet type: meat / protein (live, frozen, fresh). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Annamia Loach?

The scientific name of the species is Annamia thuathienensis, family River Loaches (Balitoridae).

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Other scientific names and conservation status

Categories
Loaches, Cold-water
Conservation status
Least concernLC