Long-whiskered Catfish
Mystus gulio
This active, nocturnal bagrid catfish features long sensory barbels. Suitable for brackish or hard freshwater, it requires a 200L tank, soft sand, hiding places, and a voracious omnivorous diet.
Water Temperature
20 - 28 °C
pH Value
7 - 8.2
Water type
Freshwater / Brackish
Tank level
Bottom and middle
Adult size
20 cm
Minimum tank volume
>= 200 L
Minimum group
>= 3
GH
4 - 15 dGH
KH
2 - 7 dKH
TDS
80 - 295 ppm
Conductivity
125 - 461 uS/cm
Species description
Geographical Origin and Habitat: Mystus gulio is native to South and Southeast Asia, found along the coasts of India, Bangladesh, Myanmar, Thailand, and Malaysia. It primarily inhabits muddy estuaries, brackish lagoons, tidal river mouths, and mangrove swamps.
Taxonomy and Morphology: Belonging to the class Actinopterygii, order Siluriformes, and family Bagridae, under the genus Mystus. It features a scaleless body, a flattened head with four pairs of long sensory barbels, and an adipose fin. It typically grows to 20 cm in captivity.
Social Behavior: Active and schooling when young, becoming more solitary as they mature. They are nocturnal predators and opportunistic feeders. While peaceful toward larger fish, they will prey on any tankmate small enough to fit into their mouth.
Coloration and Sexual Dimorphism: Body is dark greyish-brown or olive on the back, shading to a silver-white belly. The fins are dusky or translucent. Mature females are noticeably rounder, heavier-bodied, and slightly larger than males of the same age.
Care, breeding and tankmates
Aquarium Setup: A minimum tank size of 200 liters is required. Use fine sand or smooth, rounded gravel to protect their delicate sensory barbels from injury. Provide plenty of hiding spaces using large PVC pipes, driftwood, and rocks, with open space for swimming.
Diet and Feeding: Voracious omnivore. Accepts a wide variety of foods including sinking catfish pellets, frozen foods (bloodworms, mysis, brine shrimp), earthworms, and chopped seafood. Feeding should ideally occur in the evening or under dim light.
Water Quality: Best kept in brackish water (specific gravity 1.002 to 1.010), but can adapt to hard freshwater. Keep temperatures between 20°C and 28°C, and pH between 7.0 and 8.2. Strong filtration is essential to handle their high biological load.
Compatibility and Cohabitation: Keep only with larger, active fish that inhabit the middle and upper water columns, such as Scats, Monos, Archerfish, or large brackish livebearers. Avoid small species like tetras or shrimp, which will be consumed.
Aquarium Breeding: Spawning in private aquariums is very rare. They are egg-scatterers. In nature, breeding is triggered by the monsoon season, which brings drops in temperature and salinity; recreating these conditions in captivity is difficult.
Risks and Diseases: The pectoral and dorsal fin spines are sharp and can inflict painful stings; use caution when netting the fish. They are susceptible to skin infections and bacterial diseases if the substrate is coarse or poorly maintained.
Geographic Origin and Distribution
Mystus gulio is native to South and Southeast Asia, found along the coasts of India, Bangladesh, Myanmar, Thailand, and Malaysia. It primarily inhabits muddy estuaries, brackish lagoons, tidal river mouths, and mangrove swamps.
Origin
Tropical oceans and reefsSouth and Southeast Asia
Fish profile
- Temperament
- Territorial
- The overall temperament of Mystus gulio can be described as nocturnal predator. Understanding their personality is vital for maintaining a peaceful and stress-free environment. They may exhibit unique behaviors when interacting with their surroundings or during feeding time. Careful consideration of their disposition leads to a more rewarding fishkeeping experience.
- Diet
- Omnivore
- The natural diet of Mystus gulio is primarily carnivorous. In captivity, they should be offered a varied selection of high-quality foods to meet their nutritional needs. Incorporating both dry commercial diets and frozen or live options will ensure optimal health and coloration. A varied diet prevents nutritional deficiencies.
- Life expectancy
- 3-9 years
- The long-whiskered catfish (Mystus gulio) has a lifespan of 3 to 9 years in captivity, depending on care and the stability of water parameters. Being a euryhaline species, it benefits from an environment with moderate salinity, which prevents the onset of fungal infections. Efficient filtration and regular water changes are necessary to keep it healthy in the long term.
- Adult size
- 20 cm
- The catalog's scalar value is 20 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 46 cm for this species, recorded as total length (TL). The taxonomic record consulted is Mystus gulio (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Solitary
- The ideal sex ratio for keeping Mystus gulio is typically solitary. Keeping them in these numbers helps reduce intraspecific aggression and mimics their natural social structure. Providing ample hiding spots can further alleviate tension among dominant individuals. Always monitor the group dynamics when introducing new specimens.
- Feeding frequency
- Twice daily
- Feeding Mystus gulio should generally be done daily. It is important to provide only what they can consume in a few minutes to prevent leftover food from decaying. Establishing a regular feeding schedule helps keep the fish active and healthy. Adjust the frequency if you observe signs of undernourishment or overfeeding.
- Bioload
- The bioload produced by Mystus gulio is generally considered high. This means that the filtration system must be adequately sized to handle their waste output. Regular water changes and tank maintenance are strongly recommended to keep the environment healthy. Failure to do so can result in poor water quality and stress the fish.
- Flow
- Strong
- In their natural habitat, Mystus gulio experiences water flow that is moderate. Replicating this in the aquarium is crucial for their well-being and natural behavior. Appropriate water movement aids in oxygenation and prevents dead spots in the tank. Utilizing adjustable powerheads can help achieve the perfect balance.
- Jump risk
- Yes
- The risk of Mystus gulio jumping out of the aquarium is rated as moderate. Therefore, a tight-fitting lid or a secure mesh cover is highly recommended. Many fish jump when startled by sudden movements or poor water conditions. Securing the top ensures that your fish remain safely inside the tank.
- Reproduction
- Oviparous
- Regarding reproduction, Mystus gulio is known to be a egg-scatterer. Breeding them in a home aquarium requires specific water parameters and a dedicated setup. Providing the correct spawning media and conditioning the adults with high-quality foods will increase success. Raising the fry can be challenging and requires specialized microscopic foods initially.
- Compatibility & tankmates
- Community
- When it comes to compatibility, Mystus gulio is characterized as predatory. They should be housed with tank mates that share similar water requirements and temperament. Care must be taken not to include species that could easily become prey or outcompete them for food. Observation is key to ensuring a harmonious community.
- Tank level
- Middle/Bottom
- In the aquarium, Mystus gulio prefers to occupy the bottom level. Designing the aquascape to cater to this preference ensures the fish feel secure and display their best colors. Ensure that there is adequate swimming space and appropriate decor in their preferred zone. This vertical distribution also allows for careful selection of tank mates that occupy other levels.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 4 ± 0.5 se
- Resilience
- Medium (1.4 - 4.4 years)
- Generation time
- 1.5 years
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.0123, b = 2.95
- VulnerabilityLow vulnerability (23 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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