Not furry, but we like them anyway.
Knight Goby
Stigmatogobius sadanundio
Also called Knight goby, Gobius sadanundio (older name)
From South and Southeast Asia, from India, Sri Lanka and the Andaman Islands east to Singapore and Indonesia, mainly in fresh water but also in estuaries and tidal river zones123
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
At a glance the quick version
Looks how to spot one
Scaled goby
A sturdy, grey-blue goby dotted with dark spots, with two dorsal fins that also carry spots. Mature males grow taller dorsal fins and longer fins overall, while females are smaller, rounder and have a yellowish tint.23
Personality what they are like
Confident and territorial, especially near the bottom. It is a keen predator that will try to eat anything small enough to fit in its mouth, so it suits a tank of similar-sized or larger fish.32
Daily activity how busy a day looks
A bottom-oriented fish that likes to claim a cave or rock as home base and patrol its patch.23
Grooming and care the hands-on bits
Keep at about 20 to 26 C, pH 7.0 to 8.5 and hard water (10 to 20 dGH). It does well in fresh water but also enjoys light brackish conditions around SG 1.005. Wikipedia notes it likes subdued lighting.312
Home where they are happiest
Seriously Fish recommends a tank with a base of at least 75 x 30 cm (around 68 litres), with rocks, caves and clear territory boundaries.32
Food basics what goes in the bowl
An unfussy eater that takes dried, frozen and live foods. In the wild it hunts small aquatic animals such as mosquito larvae, and it also appreciates some vegetable matter.31
Company who they like around
Wikipedia advises keeping it singly because of its territorial nature. Good companions are mid-water fish of similar size, such as archerfish, chromides, rainbowfish, swordtails or sailfin mollies, rather than other bottom dwellers.32
The story where it all began
Francis Hamilton described the knight goby in 1822 from Indian waters. Its genus has been trimmed over the years from 18 to about 7 species, and this remains the member most often seen in the aquarium hobby.123
Fun facts for the dinner table
- 1
A breeding pair can produce up to about 1,000 eggs, stuck to the ceiling of a cave.1
- 2
The fry are fairly easy to raise on newly hatched brine shrimp, making it a rewarding species to breed.2
- 3
Despite being sold as a brackish fish, it is found more often in fresh water than in brackish water in the wild.3
- 4
Wikipedia notes it benefits from a small daily rise and fall in water temperature.2
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 2024)1
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Knight Goby. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkBrackish fish need a little marine salt, and some need more as they growevery week
- Water changeAbout 25% of the water, mixed to the same salinityevery week
- Water testevery week
- Filter rinseRinse in old tank water, never tap waterevery month
Owner questions the things everyone asks
How often should I feed my Knight Goby?
Furry Diary's starting plan is to feed small amounts once or twice a day. This unfussy eater takes dried, frozen and live foods, so you can vary its diet. Always check the food label and ask your vet for exact amounts.31 Furry Diary plan
What does a Knight Goby eat, and what should it never eat?
It enjoys dried, frozen and live foods like mosquito larvae, plus some vegetable matter. Never feed anything too large to fit in its mouth, as it is a keen predator that will try to eat small tank mates.31
How much space does a Knight Goby need?
Seriously Fish recommends a tank with a base of at least 75 x 30 cm, around 68 litres. Provide rocks and caves to create clear territory boundaries for this bottom-oriented fish.32
What temperature, light or water does a Knight Goby need?
Keep water at 20 to 26 C, pH 7.0 to 8.5, and hard water (10 to 20 dGH). It enjoys fresh water or light brackish conditions (SG 1.005) and prefers subdued lighting.312
How often should I clean a Knight Goby's home?
Furry Diary's plan suggests a weekly 25% water change, mixed to the same salinity, and a monthly filter rinse in old tank water. Test water weekly and check temperature daily. Furry Diary plan
Can a Knight Goby live with others?
It is best kept singly due to its territorial nature. Good companions are mid-water fish of similar size, like archerfish or rainbowfish, not other bottom dwellers.32
How long does a Knight Goby live?
Lifespan varies depending on care and environment. For specific information, please ask a good breeder or an exotic-pet vet.
Can I handle a Knight Goby?
It is best not to handle this fish, as it is a delicate aquatic creature. Enjoy watching it patrol its territory from outside the tank.
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- FishBase: Stigmatogobius sadanundio fishbase.seused for size, environment, water parameters, IUCN status, breeding, describer
- Wikipedia: Stigmatogobius sadanundio en.wikipedia.orgused for description, aquarium notes, breeding, fun facts
- Seriously Fish: Stigmatogobius sadanundio seriouslyfish.comused for distribution, water parameters, tank, diet, compatibility, sexing, taxonomy
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.