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No federal permit to keepNemacheilus triangularis
Nemacheilus triangularis
Fishes › Carp, barbs, minnows, loaches (Cypriniformes) › Nemacheilidae (Stone loaches)
Mesonoemacheilus triangularis is a species of stone loach endemic to the Western Ghats in southern Karnataka, Kerala, and Tamil Nadu, India.
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 2.3 in / 5.8 cm).
- Water: Freshwater.
- Temperature: 70–79°F (range recorded for this species).
- pH: 7–7.5.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Diet: Eats a varied diet: mix quality prepared foods with frozen and live foods. FishBase classes it as a omnivore.
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, 64–78 °F, pH 6–7.5, 2–12 dGH.
- Behaviour: a shoaling fish best kept in a group of six or more; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Not difficult to maintain under the correct conditions; we strongly recommend keeping it in a tank designed to resemble a flowing stream or river with a substrate of variably-sized rocks, sand, fine gravel, and some water-worn boulders.”
- Diet: “Mesonoemacheilus species are omnivorous although the bulk of their diet consists of small insects, worms, crustaceans and other zooplankton with only relatively small amounts of plant matter consumed.”
- Tankmates: “This species can apparently exhibit contrasting behaviour in captivity with some aquarists reporting it to be peaceful while others claim it to be territorial and aggressive.”
- Breeding: “A single success was reported by an American aquarist in 2004.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Stone loaches
Applies to most species in this group. Habitat: Eurasian stone loaches include oxygen-rich stream dwellers such as Schistura and small Vietnamese river species such as the hovering zebra loach. [fg157-sumo, fg157-hover]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For Schistura balteata groups use a floor at least 90 × 30 cm (36 × 12 in).
- Build a stream layout with sand, rounded rocks and driftwood forming numerous caves and broken sight lines.
- Use strong filtration, aeration and some flow for Schistura; change 30–50% of water weekly.
- For hovering zebra loaches use at least 60 × 30 cm (24 × 12 in), dense plants and well-oxygenated but non-turbulent water.
- Introduce hovering zebra loaches only to a biologically mature aquarium; pH 6.0–7.5 and hardness 2–12 dGH suit both profiled species.
Climate & lighting
| Water | 71.6–78.8°F |
Diet
- Small live or frozen Daphnia and Artemia.
- Bloodworms for Schistura.
- Moina, microworms and Artemia nauplii for hovering zebra loaches.
- Appropriately sized dried foods alongside invertebrates, not as the sole Schistura diet.
Social life
- Schistura defend individual caves and can harass placid bottom dwellers; groups require territories. Hovering zebra loaches are peaceful and need at least 8–10 companions.
Health watch
- Territorial fin injuries in poorly structured Schistura tanks.
- Freshwater ich, a general aquarium risk.
- Stress-associated bacterial infections.
Understanding the animal
About this animal
About this animal
It is a fairly common species occurring in streams with gravel, cobbles and bedrock with some sand as the substrate. This fish grows to a length of 5.8 centimetres (2.3 in) SL and can be found in the aquarium trade.
Quoted from the Wikipedia article “Mesonoemacheilus triangularis” (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 streams with pebbly bottom. |
| Water it lives in | Freshwater, 70–79 °F (21–26 °C), pH 7–7.5. |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 70–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 94°F in the hottest sampled areas) |
| Cool-season lows | about 66°F (down to 59°F in the coldest sampled areas) |
| Average temperature | 73–81°F across sampled records |
| Relative humidity | 70–75% on average (driest month about 63%) |
| Rainfall | about 2843 mm a year, with strong wet and dry seasons |
Measured at 15 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 | Mesonoemacheilus triangularis is a species of stone loach endemic to the Western Ghats in southern Karnataka, Kerala, and Tamil Nadu, India. It is a fairly common species occurring in streams with gravel, cobbles and bedrock with some sand as the substrate. This fish grows to a length of 5.8 cm SL and can be found in the aquarium trade. — 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 |
| Appearance and size | Maximum length 5.8 cm sl male/unsexed. — FishBase |
| Biology | Occurs in streams with pebbly 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.
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.
- Seriously Fish: Schistura balteata Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Micronemacheilus cruciatus (formerly Yunnanilus cruciatus) 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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