Home / Fishes / Carp, barbs, minnows, loaches / Gastromyzontidae / Sewellia speciosa
No federal permit to keepSewellia speciosa
Sewellia speciosa
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Gastromyzontidae (Hillstream loaches)
Sewellia speciosa is a species of fish that is part of the family Gastromyzontidae.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 2.1 in / 5.37 cm).
- Water: Freshwater.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Availability: Rarely or never seen in the aquarium trade; expect to source it from specialists or not at all.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 30 × 12 in (roughly 18 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–75 °F, pH 6–7.5, 1–10 dGH.
- Behaviour: a shoaling fish best kept in a group of six or more; suited to a community tank.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “The water must be clean, well-oxygenated, and ideally turn over 15-20 times per hour so we suggest the use of an over-sized filter as a minimum requirement plus additional powerheads, airstones, etc., as necessary.”
- Diet: “Much of the natural diet is composed of benthic algae plus associated micro-organisms although insect larvae are probably taken on an opportunistic basis.”
- Tankmates: “In terms of behaviour Sewellia spp.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Hillstream loaches
Applies to most species in this group. Habitat: Balitora inhabit fast-flowing Asian hillstream riffles with rocky beds and abundant dissolved oxygen. [fg177-bal]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Use a long river aquarium; the river-tank reference recommends at least 3 feet of length, rather than a species-tested minimum.
- Provide strong directional current and vigorous aeration throughout the occupied area.
- Supply smooth pebbles, boulders and numerous rocky refuges out of the main current.
- Use bright lighting and an established aquarium with grazing growth on rocks.
- For B. brucei, maintain pH 7.0–8.0 and medium hardness up to 12 dGH.
Climate & lighting
| Water | 68–75°F |
Diet
- Algae and established rock biofilm.
- Frozen bloodworms and mysis shrimp.
- Pelleted foods.
Social life
- Provide separate resting and feeding surfaces; hillstream keepers report competition for favored rocks, but a Balitora-specific group size is not established here.
Health watch
- Oxygen deprivation, especially during overheating or inadequate aeration.
- Poor condition from inadequate access to established grazing growth.
- Skin disease with patchy coloration and loss of appetite; obtain a diagnosis rather than treating by appearance alone.
Understanding the animal
About this animal
About this animal
The fish is found in both Laos and Vietnam. It reaches up to 5.4 centimeters in length.
Quoted from the Wikipedia article “Sewellia speciosa” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Stays near the bottom. Inhabits rivers with rocky bottom, with gravel and stone and sometimes large boulders. River current is moderate to swift, but the gradient is moderate. |
| Water it lives in | Freshwater. |
| Climate | Tropical climate. |
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Biology | Inhabits rivers with rocky bottom, with gravel and stone and sometimes large boulders. River current is moderate to swift, but the gradient is moderate. — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates; aim for the middle.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 30 × 12 in (about 18 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Loaches Online: Balitora brucei Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Loaches Online: Hillstream Loaches — The Specialists at Life In The Fast Lane Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual: Disorders and Diseases of Fish Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
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