A distinct, high-bodied goby found in estuaries across South Asia. Unlike most bottom-dwelling gobies, the Knight Goby frequently hovers in the water column. While often sold as freshwater fish, they thrive best in slightly brackish water (SG 1.003-1.005) or very hard, alkaline freshwater. They are territorial and notorious fin-nippers, making them poor tankmates for Guppies or Bettas.
Knight Goby At a Glance
Knight Goby Tank Requirements
Will Knight Goby fit in your tank?
Care guides tell you what Knight Goby needs, the next question is whether your tank can safely provide it. Test Knight Goby against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Knight Goby Water Parameters
Water care products
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Knight Goby Temperament & Compatibility
Knight Goby Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard wild-type form. Males typically have longer, more pointed fins and a lighter grey body compared to the yellowish, smaller-finned females. Best kept singly or in a mated pair; groups require large tanks to prevent territorial fighting.
Differs in 1 trait from base species
Knight Goby Care Guide Summary
The Knight Goby, scientifically known as Stigmatogobius sadanundio, belongs to the Gobies & Gudgeons family group. Adults reach a maximum size of approximately 9 cm and have a fusiform body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a medium level of biological waste.
To thrive, the Knight Goby requires a brackish tolerant aquarium with a minimum volume of 75 litres and a tank length of at least 60 cm. Water temperature should be maintained between 20°C and 28°C, with a pH range of 7–8.5 and a general hardness of 10–30 dGH. A moderate water flow is preferred.
Due to its specialist needs, the Knight Goby is best suited for fishkeepers who can provide a carefully planned setup. The Knight Goby is typically available in one standard form.
Knight Goby Habitat Setup
When setting up an aquarium for the Knight Goby, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, driftwood, which can serve as both a hiding place and a dietary supplement, and shells for breeding and shelter. Keepers should note that expect substrate disturbance, so lightweight décor should be secured.
Knight Goby Compatibility Notes
Classified as semi-aggressive, the Knight Goby is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, avoid housing with slow-moving or long-finned species that may become targets for fin nipping, ornamental shrimp are not safe companions, conspecific aggression can be intense, especially in smaller tanks, and territorial behaviour may cause issues if hiding spots or floor space are limited. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.
Knight Goby Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Knight Goby.
20 Gallon High
20 Gallon Long
29 Gallon Standard
30 Gallon Breeder
36 Gallon Bowfront
40 Gallon Breeder
Show 17 more tank sizes
Knight Goby Feeding & Diet Considerations
The Knight Goby will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups and will eat fry, so breeding efforts in the same tank are unlikely to succeed.
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Frequently Asked Questions About Knight Goby
How big does Knight Goby get?
Knight Goby (Stigmatogobius sadanundio) typically reaches a maximum adult size of approximately 9 cm. They have a fusiform body shape and a moderate growth rate.
What tank size does Knight Goby need?
A minimum aquarium volume of 75 litres and a tank length of at least 60 cm are recommended for Knight Goby. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Knight Goby need?
Knight Goby thrives in brackish tolerant conditions with a temperature range of 20–28°C, a pH between 7 and 8.5, and a general hardness of 10–30 dGH. A moderate water flow is preferred.
Is Knight Goby peaceful or aggressive?
Knight Goby is classified as semi-aggressive with an aggression score of 6 out of 10. They can work in community setups but may clash with certain tankmates.
Can Knight Goby live alone?
Yes, Knight Goby can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Knight Goby safe with shrimp?
No. Knight Goby is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Knight Goby have any special tank requirements?
Yes. Knight Goby benefits from sand (sifters), shells (breeding/hiding), and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Plants That Suit Knight Goby
These plants pair well with Knight Goby based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Anubias Barteri
Anubias barteri
Belinda's Buce
Bucephalandra belindae
Buce Motleyana
Bucephalandra motleyana
Christmas Moss
Vesicularia montagnei
Congo Anubias
Anubias heterophylla
Fish Similar to Knight Goby
Marble Goby
Oxyeleotris marmorata
The Marble Goby (Soon Hock) is one of the largest freshwater gobies in the world. As a strictly carnivorous, nocturnal ambush predator, it is incredibly inactive during the day but will swallow any tankmate that fits into its massive mouth. Due to its enormous adult size, it is strictly a 'monster fish' and requires highly specialized care and heavy filtration.
Peacock Gudgeon
Tateurndina ocellicauda
A stunning, peaceful freshwater sleeper goby from Papua New Guinea. Known for their vibrant blue, red, and yellow colors, they are excellent nano-tank inhabitants. They are not true gobies (they lack fused pelvic fins) and are exclusively freshwater. They prefer slow-moving water, dense vegetation, and small caves (like PVC pipes or smooth stones) for spawning.
Neon Blue Goby
Stiphodon atropurpureus
A stunning, specialized freshwater goby native to fast-flowing hill streams in Asia. Males display brilliant neon blue metallic coloration, while females are striped. They are specialized biofilm grazers ('Aufwuchs' eaters) and require mature tanks with established algae/biofilm stones. They are obligate stream dwellers requiring high oxygen and strong flow.
Bumblebee Goby (Brackish)
Brachygobius xanthozonus
A miniature, bottom-dwelling goby famous for its striking black and yellow stripes. While they are often sold as freshwater fish and can survive in it temporarily, they are highly susceptible to fungal infections in fresh water and truly require a brackish setup (SG 1.002-1.005) to thrive long-term. They are notoriously picky eaters, often ignoring flakes in favor of live or frozen foods (like bloodworms or brine shrimp).
Empire Gudgeon
Hypseleotris compressa
A remarkably adaptable and beautifully colored sleeper goby (not a true goby) native to Australia and New Guinea. They inhabit both pure freshwater streams and brackish estuaries. While generally peaceful and excellent community fish, they are micropredators that will happily consume dwarf shrimp and very small fry.
Violet Goby (Dragon Goby)
Gobioides broussonnetii
Often misunderstood due to its terrifying 'Dragon' appearance and sharp teeth, the Violet Goby is actually a gentle, nearly blind scavenger and filter feeder. It uses its teeth to scrape algae, not to bite fish. It requires brackish water to thrive long-term and fine sand to sift through for food. It is not a predator.