Home / Fishes / Gobies and sleepers / Stigmatogobius sadanundio
No federal permit to keepStigmatogobius sadanundio
Stigmatogobius sadanundio
Fishes › Gobies and sleepers (Gobiiformes) › Gobiidae (Gobies)
Stigmatogobius sadanundio is a species of goby native to south Asia from India to Indonesia including Sri Lanka and the Andaman Islands.
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 3.5 in / 9 cm).
- Water: Freshwater (tolerates brackish).
- Temperature: 68–79°F (range recorded for this species).
- pH: 7–8.
- Hardness: 9–19 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: 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 30 × 12 in (roughly 18 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–79 °F, pH 7–8.5, 10–20 dGH.
- Behaviour: temperament predatory.
- Difficulty: Easy (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “A soft, sandy substrate is ideal for this species.”
- Diet: “An unfussy goby that will accept most dried, frozen and live foods.”
- Tankmates: “Don't try to keep it with much smaller species as it will eat anything it can fit in its mouth.”
- Breeding: “Has been achieved in the hobby but is not very well-documented.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Gobies
Applies to most species in this group. Habitat: The listed gobies span marine sand burrows and rocky coasts as well as freshwater streams, where Stiphodon grazes biofilm in clear, oxygen-rich water. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For Valenciennea puellaris, provide at least 30 US gallons, live sand and a populated attached refugium.
- For Stiphodon ornatus, provide a base at least 80 × 30 cm (about 31 × 12 inches).
- Provide mature, illuminated, algae-covered rocks and strong oxygenation for Stiphodon.
- Seat Stiphodon rocks directly on the tank base, break sight lines with refuges and fit a tight cover.
- V. puellaris is sourced at specific gravity 1.020–1.025 and pH 8.1–8.4; adult Stiphodon require freshwater, pH 6.5–7.5 and 2–12 dGH.
Diet
- For Valenciennea: live or frozen mysis and brine shrimp, fed frequently.
- For Valenciennea: live blackworms and prepared carnivore foods.
- For Stiphodon: mature algal biofilm and associated microorganisms.
Social life
- Valenciennea puellaris fights conspecifics unless they are a mated pair. Separate Stiphodon male territories with rockwork; one social arrangement cannot represent this family.
Health watch
- Ammonia toxicity.
- Nutritional deficiencies.
Understanding the animal
About this animal
About this animal
It can be found in mostly fresh waters (occasionally in brackish waters) of estuaries and the tidal zones of rivers. It can also be found in the aquarium trade, where it is often marketed as the knight goby.
Quoted from the Wikipedia article “Stigmatogobius sadanundio” (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 and brackish water, in rivers and streams, estuaries. Uses both the bottom and open water. Occurs in estuaries and tidal zone of rivers. Prefers fresh water, rarely found in brackish water. Feeds on small fishes and invertebrates, including mosquito larvae. |
| Water it lives in | Freshwater / brackish water, 68–79 °F (20–26 °C), pH 7–8, hardness 9–19 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: nesters. |
What this means for care
- Keep water within its wild range, 68–79 °F.
- It tolerates or needs brackish water; check salinity needs before setup.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 95°F in the hottest sampled areas) |
| Cool-season lows | about 69°F (down to 55°F in the coldest sampled areas) |
| Average temperature | 79–82°F across sampled records |
| Relative humidity | 77–81% on average (driest month about 71%) |
| Rainfall | about 2168 mm a year, with strong wet and dry seasons |
Measured at 26 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 | Stigmatogobius sadanundio is a species of goby native to south Asia from India to Indonesia including Sri Lanka and the Andaman Islands. It can be found in mostly fresh waters (occasionally in brackish waters) of estuaries and the tidal zones of rivers. It can also be found in the aquarium trade, where it is often marketed as the knight goby. — 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 |
| Reproduction | Produces up to 1000 eggs. — FishBase |
| Appearance and size | There are two dorsal fins on this gray-blue fish: the first consists of about six stiffly held rays (often with a black blotch); the second is equal in length to the long-based anal fin. This species can reach a length of 9 cm SL. — Wikipedia (community-edited) |
| Biology | Occurs in estuaries and tidal zone of rivers. Prefers fresh water, rarely found in brackish water. Feeds on small fishes and invertebrates, including mosquito larvae. — 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 — Stiphodon ornatus Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- LiveAquaria — Diamond Watchman Goby Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Tropical Fish Hobbyist — Gobies in My Aquarium 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.
- 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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