Home / Fishes / Carp, barbs, minnows, loaches / Botiidae / Dwarf loach
No federal permit to keepDwarf loach
Ambastaia sidthimunki
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Botiidae (Clown, yoyo and other loaches)
The dwarf loach, ladderback loach, pygmy loach, chain loach or chain botia (Ambastaia sidthimunki) is a freshwater fish belonging to the family Botiidae.
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 2.2 in / 5.5 cm).
- Water: Freshwater.
- Temperature: 79–82°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–19 dGH.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
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 31 × 12 in (roughly 19 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–86 °F, pH 5.5–7.5, 1–12 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: “All botiids require a well-structured set-up although choice of décor is more-or-less down to personal taste, with A.”
- Tankmates: “This species is generally considered to be an excellent choice for the community aquarium, but caution should possibly be exercised since conflicting observations exist.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Clown, yoyo and other loaches
Applies to most species in this group. Habitat: Botiids inhabit Asian freshwater rivers and tributaries, including forested headwaters and seasonally flooded river margins. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Provide at least an 80 × 30 cm (31 × 12 in) base for dwarf chain loaches; clown loaches require at least 180 × 60 cm (71 × 24 in).
- Use sand or fine gravel, smooth rocks, roots and numerous shelters; fill trapping holes and remove sharp edges.
- Fit a tight lid.
- Use a mature biological filter and maintain well-oxygenated water with some flow.
- Perform routine weekly water changes of 30–50% for the dwarf chain loach setup.
Climate & lighting
| Water | 75.2–86°F |
Diet
- Quality sinking dried foods
- Live or frozen bloodworms
- Daphnia or Artemia
- Blanched spinach or courgette
Social life
- For clown and dwarf chain loaches, keep at least 5–6 conspecifics, preferably 10 or more; pairs and trios can suffer severe dominance stress. Avoid slow, long-finned tankmates.
Handling
- Take care with the erectable subocular spines when moving loaches; they can become entangled in nets.
Health watch
- Stress and failure to feed in undersized social groups
- Entrapment injuries in narrow décor
- Water-quality illness from accumulated organic waste
Understanding the animal
About this animal
About this animal
Formerly included in the genus Yasuhikotakia, it is frequently seen in the aquarium trade, the product of captive breeding. This endangered species is endemic to the Mae Klong basin (including Khwae Noi River) in Thailand, and the Ataran River on the Thai-Myanmar border.
Quoted from the Wikipedia article “Dwarf loach” (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, in rivers and streams. Stays near the bottom. Occurs in medium to large-sized rivers and flooded fields. |
| Water it lives in | Freshwater, 79–82 °F (26–28 °C), pH 6–8, hardness 5–19 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: open water/substratum egg scatterers. |
What this means for care
- Keep water within its wild range, 79–82 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 94°F (up to 97°F in the hottest sampled areas) |
| Cool-season lows | about 67°F (down to 62°F in the coldest sampled areas) |
| Average temperature | 78–83°F across sampled records |
| Relative humidity | 72–74% on average (driest month about 62%) |
| Rainfall | about 1400 mm a year, with strong wet and dry seasons |
Measured at 7 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
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.
| Overview | The dwarf loach, ladderback loach, pygmy loach, chain loach or chain botia (Ambastaia sidthimunki) is a freshwater fish belonging to the family Botiidae. Formerly included in the genus Yasuhikotakia, it is frequently seen in the aquarium trade, the product of captive breeding. This endangered species is endemic to the Mae Klong basin (including Khwae Noi River) in Thailand, and the Ataran River on the Thai-Myanmar border. Records from the Mekong basin are misidentifications of the very similar and closely related A. nigrolineata. — Wikipedia (community-edited) |
| 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 | Occurs in medium to large-sized rivers and flooded fields. Found in small muddy lakes and other standing water habitats. Active by day and often schools in some distance above the bottom. — 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 in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 31 × 12 in (about 19 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.
- Seriously Fish: Chromobotia macracanthus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Ambastaia sidthimunki Experienced keeper or breederAdded 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.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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