Species profile
Hillstream Loach
Sewellia lineolata
Peaceful
Hard care
100 L minimum aquarium
5–6.5 cm adult size
Bottom
Minimum group: 3
About this species
General notes for hobby use.
Rheophilic hillstream loach requiring very high dissolved oxygen, strong directional flow and mature rock surfaces for grazing.
Water parameters
Suggested general range for long-term care.
Temperature
22–26 °C
pH
6–7.5
GH
Up to 15 dGH
KH
Not yet documented
Flow preference
High
Data confidence
Verified
Behaviour
General behaviour traits used by TanksConnected compatibility checks.
Minimum group size
Minimum group: 3
Tank zone
Bottom
Territory level
Low
Predation risk
None
Bioload factor
0.8
Individuals may defend favoured grazing rocks but interactions are generally ritualised. Do not keep in warm, stagnant low-oxygen tanks.
Compatibility flags
Quick cautions for common tank-planning issues.
Fin nipper
No
Plant safe
Yes
Shrimp safe
Yes
Snail safe
Yes
Cave breeder
No
Digs substrate
No
Jump risk
Yes
Natural history & care
Research-backed context for long-term aquarium care.
Lifespan
Not yet documented
Diet type
Omnivore
Minimum aquarium volume
100 L
Minimum footprint
90 × 35 cm
Accepted scientific name
Sewellia lineolata
Alternative names
Reticulated Hillstream Loach, Gold Ring Hillstream Loach
Native range
Vietnam, Laos and Cambodia in the Mekong region.
Natural habitat
Fast, shallow riffles and rapids over rock/cobble where oxygen and current are consistently high.
Diet & feeding
Grazes biofilm/algae and consumes small benthic invertebrates; mature aufwuchs surfaces plus supplemental foods are important.
Breeding & sexing
Research-backed guidance for identifying sexes and reproductive behaviour.
Sexing
Males develop stronger tubercles/raised structures on pectoral rays and a squarer head/shoulder profile; females are rounder.
Breeding
Aquarium spawning occurs in mature high-flow tanks; eggs/fry may develop within substrate interstices, but controlled breeding is not routine.