Tiger hillstream loach
Sewellia lineolata
Also known as Reticulated Hillstream Loach
FreshwaterFish
Care at a glance
- Temperature
- 68–75°F
- 20–24°C
- pH
- 6.0–7.5
- Adult size
- 2.6 in
- 6.5 cm
- Minimum tank
- 25 gal
- 95 L
- Temperament
- Peaceful
- Social behavior
- Social
- Swim level
- Bottom
- Difficulty
- Medium
- Breeding
- Hard
- Rarity
- Rare
- Family
- Gastromyzontidae
- Origin
- Vietnam
Overview
The tiger hillstream loach is a finely patterned, flat-bodied grazer that clings to rocks and glass in fast water. It is social and peaceful, so keep a group of six or more and they will fan out across the hard surfaces, feeding and displaying to one another through the day. Their main food is the biofilm and algae on stones, topped up with sinking wafers, biofilm blocks, and small frozen foods once a mature film has built. Pair them with calm, cool-water fish that enjoy the same strong current. A group needs a well-oxygenated tank of around 95 liters or larger with brisk flow and lots of rockwork.
In the wild
Sewellia lineolata comes from central Vietnam, where it lives in shallow, fast-flowing streams tumbling over rock and cobble in cool, oxygen-saturated water. It needs those conditions recreated closely, around 20 to 24 C with a pH from about 6 to 7.5 and a powerful current. Use a strong filter or powerhead to drive the flow, provide smooth stones and cobbles for grazing and spawning, and keep the tank mature so a rich film of algae develops. High oxygen, cool temperatures, and spotless water are the foundations of keeping this fish well.
Good to know
Sewellia lineolata is a member of Gastromyzontidae, the hillstream loaches, and grows to about 6.5 cm. Its flattened body and fused paired fins form a suction disc that holds it against rock in ripping current, and it has no eye spine like the botiid loaches. Unusually for a hillstream loach, it will breed in a mature, well-run aquarium, scattering eggs that fall into gaps in the gravel, though coaxing and raising the fry is difficult. It gives no parental care.
Did you know
The tiger hillstream loach is one of the very few hillstream loaches that breeds in home aquariums, which is why tank-raised Sewellia are now widely available. Given strong flow, cool water, and a mature tank, established groups will spawn on their own without hormones or special conditioning.
Weekly picks
Tank mates
Tiger hillstream loach is a peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Lake Tebera rainbowfish
Melanotaenia herbertaxelrodi
Freshwater3.5 in (9 cm) · 25 gal (95 L)68–79°F (20–26°C)
Striped flying barb
Esomus metallicus
Freshwater3 in (7.5 cm) · 24 gal (90 L)72–79°F (22–26°C)
Nan River loach
Hemimyzon nanensis
Freshwater2.8 in (7 cm) · 24 gal (90 L)64–75°F (18–24°C)
Croaking gourami
Trichopsis vittata
Freshwater2.8 in (7 cm) · 25 gal (95 L)72–82°F (22–28°C)
Wrestling halfbeak
Dermogenys pusilla
FreshwaterBrackish2.8 in (7 cm) · 25 gal (95 L)75–82°F (24–28°C)
Barred loach
Nemacheilus fasciatus
Freshwater3.1 in (8 cm) · 24 gal (90 L)68–77°F (20–25°C)
Common questions
What size tank does a Tiger hillstream loach need?
A Tiger hillstream loach needs at least 25 gal (95 L). It spends most of its time in the bottom.
What temperature and pH does a Tiger hillstream loach need?
A Tiger hillstream loach is comfortable at 68–75°F (20–24°C) with a pH of 6.0–7.5.
How big does a Tiger hillstream loach get?
An adult Tiger hillstream loach reaches about 2.6 in (6.5 cm).
Related species
2.6 in (6.5 cm)24 gal (90 L)68–75°F (20–24°C)Showy hillstream loach
Sewellia speciosa
2.6 in (6.5 cm) · 24 gal (90 L)
2.4 in (6.2 cm)24 gal (90 L)68–75°F (20–24°C)Pako hillstream loach
Sewellia breviventralis
2.4 in (6.2 cm) · 24 gal (90 L)
2.4 in (6 cm)24 gal (90 L)68–75°F (20–24°C)Finespot hillstream loach
Sewellia analis
2.4 in (6 cm) · 24 gal (90 L)
2.6 in (6.5 cm)20 gal (75 L)68–75°F (20–24°C)Spotted hillstream loach
Gastromyzon punctulatus
2.6 in (6.5 cm) · 20 gal (75 L)
2.6 in (6.5 cm)20 gal (75 L)72–79°F (22–26°C)Yellowfin Borneo sucker
Gastromyzon viriosus
2.6 in (6.5 cm) · 20 gal (75 L)
2.4 in (6.2 cm)20 gal (75 L)68–77°F (20–25°C)Starry Borneo sucker
Gastromyzon stellatus
2.4 in (6.2 cm) · 20 gal (75 L)
