Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Ambastaia nigrolineata

Black Lined Loach

Black Lined Loach, Ambastaia nigrolineata Black Lined Loach, Ambastaia nigrolineata
Photos by Andy Rapson


Named for Ambastai (or Ambastus in Latin), a river in Ptolemy’s  (identified as the Mekong).

General Notes:

Black Lined Loaches come from shallow rivers and streams with a good flow and they require clean well aerated water if they are to thrive. Use soft sand as a substrate in order to avoid damage to their barbels. They should be kept in large groups because they form strong hierarchies, if too few are kept it will result in bullying, A group of five to ten individuals should get along without serious bullying once a pecking order has been established.
Unusually for a loach these fish spend a lot of their time in the upper reaches of the water column.


Aquatic insect and larvae form the bulk of their natural diet. In captivity they are relatively unfussy and will accept live or frozen blood worms, daphnia, cyclops, brine shrimps. They will also take suitably sized pellets and flake food along with a range of fresh greens such as cooked peas without their skin and cucumber. Black lined loach will also eat any snails in the aquarium and they may nibble plants.


Generally peaceful but needs to be part of a group. Black lined loaches may nip fish which have long flowing fins.


Adult males are smaller, more slender and more have slightly stronger colours than adult females.


Black lined loaches have not been bred under normal aquarium conditions.

Wild status

Ambastaia nigrolineata is listed as being vulnerable by the ICUN Red List of Endangered Species.
Habitat degradation is the main threat all across its range. It is thought that there has been a 30% drop in the wild population in the last decade.

Additional information

This species is not often seen for sale and it is easily confused with A. sidthimunki.

Information at a glance

pH: 6.5 - 7
dGH: 4 - 12
Temperature: 15 - 25°C (59 - 78°F)
Diet: Omnivore
Size: 10cm (4in)
Min tank size: 100 litres
Difficulty level: easy
Aquarium type: Community
Swimming level: Mid to top

Distribution and habitat

distribution map for Helostoma temminckii

Origin: Asia: Mekong basin in China and the Nan river drainage in northern Thailand

Habitat: Found in small creek with sandy bottom and moderate current and hill streams


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cobitidae
Genus: Ambastaia
Species: A. nigrolineata, (Kottelat & Chu, 1987)

Other common names:

Botia nigrolineata,
asuhikotakia nigrolineata