Walking Catfish – Clarias batrachus

The walking catfish, Clarias batrachus, is one of those aquarium fish that instantly provoke curiosity. Long body, moustache-like barbels, and the legendary ability to “walk” across land make it unforgettable. In the home aquarium, however, this species is demanding and suited only to aquarists ready for a powerful, intelligent and sometimes mischievous companion. Below you will find a detailed guide that will help you decide whether the walking catfish is right for your aquarium and how to care for it responsibly.

Walking Catfish in Nature – Why It Is So Unique

In the wild, walking catfish inhabit warm waters of Southeast Asia: slow rivers, rice paddies, swamps and temporary ponds. These are often muddy, low-oxygen environments where many other fish would not survive. Clarias batrachus evolved a special breathing apparatus – a labyrinth-like organ that allows it to breathe atmospheric air. Thanks to this, it can live in waters that are extremely poor in oxygen, and even survive out of water for a certain amount of time as long as it remains moist.

Their famous “walking” ability comes from strong pectoral fins equipped with hard spines. The fish uses them as improvised legs, pushing and dragging itself over moist ground from one puddle to another. In monsoon regions, this skill is crucial: when one body of water dries up, the catfish can move to another and avoid death. This adaptation made the species very resilient but also caused problems in regions where it was introduced as a food fish and then escaped or was released into the wild.

In several countries, especially in parts of the United States, walking catfish are now considered an invasive species. They outcompete native fish populations and can travel between canals, ditches and ponds during rainy periods. This ecological context is important for aquarists: keeping this fish in an aquarium should always be tied to a strong sense of responsibility and legal awareness. Before buying, you should check local regulations, because in some areas possession, sale or transport of walking catfish is restricted or banned.

From the perspective of fishkeeping, their natural environment tells us a lot about their preferences. They like warm water, gentle current, muddy or sandy bottoms and many hiding places. They are nocturnal predators, most active at dusk and at night. This influences the way we design the aquarium and the type of tank mates we choose. Understanding their biology is the key to successful long-term care.

Appearance, Behaviour and Temperament in the Aquarium

The walking catfish has an elongated, cylindrical body, slightly flattened towards the head. The skin is smooth and scaleless, covered with a protective mucus layer. Colouration varies from brown and grey to almost black, sometimes with lighter spots or marbling. The dorsal fin runs almost the entire length of the body, and the head is decorated with long barbels that the fish uses as sensory organs. Adult specimens can easily reach 30–40 cm, and in very spacious tanks even more, which must be taken into account during planning.

Behaviorally, Clarias batrachus is an intelligent and very active fish, especially after lights-out. During the day, it often rests in a shelter, under roots or in dense vegetation, but with time it can become bolder and swim in the open. Many aquarists notice that the walking catfish quickly learns feeding routines and even reacts to the presence of people in front of the aquarium. It can be compared to a water-dwelling predator that gradually starts associating the aquarist with food.

Temperament is usually described as semi-aggressive to aggressive, mainly because of feeding behaviour. The walking catfish is opportunistic and will try to eat anything that fits into its mouth: smaller fish, shrimps, and even some larger but slow tank mates may be at risk. It is very robust and not easily intimidated, so it can outcompete peaceful species during feeding. At the same time, it does not constantly “chase” other fish like some cichlids; rather, it focuses on ambush and nocturnal hunting.

Because of its strong muscles and body structure, the walking catfish can uproot plants and move decorations while swimming or digging. It also tends to explore the upper parts of the aquarium and test any openings. This is one of the few aquarium fish that can genuinely escape from an uncovered tank and survive for a while on the floor. For this reason, a well-secured cover is not a recommendation but an absolute necessity. At MB Store you will find aquariums with tight-fitting lids and covers that help prevent such unwanted adventures.

Setting Up the Ideal Aquarium for Clarias batrachus

Keeping walking catfish requires a carefully planned environment. The first and most critical aspect is tank size. Although juveniles may seem small and harmless, they grow quickly. For a single adult, a minimum of 250–300 litres is recommended, and more is always better. A long tank (rather than a tall, narrow one) provides more swimming space and better mimics their natural habitats, which tend to be shallow and wide. When planning the layout, it is better to think from the perspective of a large, powerful fish rather than a small community species.

Regarding water parameters, walking catfish are tolerant but still need stability and quality. Optimal temperature ranges from 24 to 28 °C. pH should be between 6.5 and 7.5, and general hardness in the soft to moderately hard spectrum. They can cope with temporary fluctuations or slightly worse conditions, but this should not be used as an excuse to neglect regular maintenance. Good filtration and frequent water changes are crucial, because these fish produce a lot of waste and eat generously.

High-quality external filters or powerful internal filters available at MB Store are advisable. A strong filter ensures mechanical and biological purification, but the current should not be too intense across the entire tank. It is wise to create zones with calmer water using decorations and plants so that the fish can choose the area most comfortable for it. Adequate aeration is helpful, though the walking catfish can breathe air; the rest of the aquarium inhabitants will certainly benefit, and the overall ecosystem will be more stable.

Substrate should be soft – sand or fine smooth gravel – because the fish likes to dig and rest at the bottom. Sharp stones or rough gravel can damage its delicate skin. Arrange hiding spots using roots, caves, coconut shells or ceramic tubes. The walking catfish feels safer with at least a few shelters; this also reduces stress and may slightly moderate aggressive tendencies. Decorations sold at MB Store allow you to build complex, safe structures without sharp edges.

Plants in tanks with Clarias batrachus are a matter of debate. On the one hand, they improve water quality, provide shade and look attractive. On the other hand, a strong, active catfish can uproot or damage them. It is worth choosing robust species with strong roots such as large Anubias, Java fern attached to roots and stones, or hardy Vallisneria. Floating plants are also a good idea, because they dim the light and provide a sense of security. You should, however, be prepared that from time to time you will need to replant or rearrange the décor.

Lighting does not have to be extremely strong. Walking catfish prefer dim conditions and are more active at dusk. Moderate light, coupled with dark substrate and drifting shadows from roots and plants, will create a more natural, calming environment. A programmable lighting system, easily connected with modern aquariums and lids from MB Store, can simulate gradual sunrise and sunset and thus support the fish’s biological rhythm.

Another important element is a solid and sealed cover. The walking catfish can push up loose lids, find gaps around cables or holes for equipment. Each cable opening should be secured, for example with sponge or special cover elements. An uncovered or poorly covered tank is a serious risk not only for this species but also for the household – a large fish on the floor is an unpleasant surprise for both sides.

Feeding and Nutrition – A True Predator at the Table

Clarias batrachus is a classic omnivorous predator with a strong craving for animal protein. In the wild, it eats insect larvae, small fish, crustaceans, worms and almost anything edible that falls to the bottom. In the aquarium, such a diet can be successfully replicated using a combination of live, frozen and high-quality dry foods. Proper nutrition is crucial to maintain health, vitality and attractive appearance.

As a base, sinking pellets or granules designed for large carnivorous or omnivorous fish work well. They should contain a solid proportion of animal protein, vitamins and balanced fats. MB Store offers a wide range of feeds tailored to predators and bottom-dwelling species, which makes it easier to compose a diversified menu. It is important to choose products that do not disintegrate too quickly in water, so as not to burden the filter and water parameters.

Supplement this base with frozen foods such as bloodworms, krill, shrimps, pieces of fish fillet or mussels. Occasional live food – earthworms, mealworms or feeder fish from safe sources – can stimulate natural hunting instincts and provide mental enrichment. However, live food should be used thoughtfully, both for ethical reasons and to avoid introducing diseases. Always buy from trusted suppliers or breed feeder organisms yourself.

Although animal protein dominates, it is beneficial to add a small share of plant-based components: spirulina-based pellets, blanched vegetables (zucchini, peas, spinach) or commercial mixes with plant additives. This helps digestion and provides additional micronutrients. The walking catfish is not a herbivore, but like many omnivores, it takes advantage of any accessible food source in small amounts.

The key rule in feeding Clarias batrachus is moderation. These fish have a voracious appetite and can easily overeat, leading to obesity, fatty degeneration of organs and deterioration of water quality. It is better to feed smaller portions 1–2 times a day rather than a large amount once. Observe how fast food is eaten: an adult walking catfish should finish a meal in just a few minutes. Leftovers should be removed using a siphon or net to prevent rotting.

At night, when the catfish is most active, you can offer the main portion of food. If the aquarium is lit more in the evening, feeding shortly after lights-out will correspond to its natural rhythm. It is also worth adapting feeding to the tank mates: faster midwater fish may try to grab most of the pellets, so choose sinking foods and feed in a way that the walking catfish can easily find its share. Regular, varied feeding combined with clean water will encourage strong growth, a robust immune system and lively behaviour.

Tank Mates, Compatibility and Legal Considerations

Choosing companions for a walking catfish is a complex question. On one hand, it is possible to keep this species in community tanks; on the other, mistakes easily end in lost fish or long-term stress. The basic rule is simple: do not keep Clarias batrachus with anything that fits in its mouth or is much more peaceful and delicate. Nano fish, small tetras, rasboras, shrimps or ornamental snails are completely unsuitable as companions.

Better candidates are large, robust species such as certain cichlids, big barbs, silver dollars, or larger catfish of comparable size. However, even in such company, problems may arise. During nocturnal hunting, the walking catfish can attack sleeping fish or eat eggs and fry. Therefore, it is usually best to avoid pairing it with species that you plan to breed in the same tank. If you want to attempt cohabitation, create many visual barriers and shelters that will reduce direct contact and increasing the chance of peaceful co-existence.

Sometimes aquarists decide to keep the walking catfish in a single-species aquarium. This can be an excellent solution, especially if you want to focus on observing the behaviour of this fascinating fish without worrying about tank mates. In such conditions, the catfish often becomes tamer and more “interactive” with the keeper. You can then tailor the entire aquascape, filtration and feeding pattern to its specific needs.

Legal aspects must not be ignored. In several countries and regions, especially where Clarias batrachus has become an invasive species, legal limitations are strict. They may include bans on import, trade, keeping or release into local waters. Before you decide to purchase, check regulations in your area – for example by consulting environmental agencies or up-to-date online legal resources. Acting in accordance with the law protects local ecosystems and prevents serious penalties.

Responsibility also applies to situations when you decide that the walking catfish is no longer suitable for you. Under no circumstances should the fish be released into natural bodies of water. It may survive, reproduce or spread diseases to native fauna. Alternatives include returning the fish to the store, offering it to other experienced aquarists or contacting local aquarium associations. Responsible ownership is a foundation of ethical fishkeeping, and MB Store supports such an approach by promoting education and awareness among customers.

Remember as well that the walking catfish is a long-term commitment. With proper care, it can live more than ten years. Before buying, consider not only the size of your current aquarium and budget, but also your long-term plans and potential future moves. MB Store offers not only tanks and aquarium equipment, but also advice in choosing systems that can grow with your passion – for example modular aquariums and filters that can handle future upgrades.

Health, Common Problems and Long-Term Care

Walking catfish are robust and resistant fish, but like any aquarium resident, they can fall ill under poor conditions. One of the most common problems is stress caused by too small a tank, lack of hiding spots, overly aggressive tank mates or poor water quality. Chronic stress weakens the immune system and opens the door to infections. Symptoms can include hiding all the time, refusal to eat, rapid breathing or abnormal swimming.

Skin damage is another frequent issue. Because Clarias batrachus has no scales, its skin is more susceptible to injuries from sharp decorations, rough substrate or rough handling with nets. Damaged areas can become infected with bacteria or fungi, leading to ulcers and systemic diseases. To minimise risk, use a soft substrate, smooth decorations and handle the fish carefully. When you need to move it, use large, soft nets or containers rather than traditional small nets.

Like other aquarium fish, walking catfish can suffer from external parasites (such as Ichthyophthirius), bacterial infections or internal parasites. Prevention is based on quarantine of new fish and plants, regular water changes, and stable parameters. If you notice symptoms such as white spots, fuzzy patches, swelling, or changes in appetite and behaviour, react quickly: test water parameters, improve conditions and, if necessary, use appropriate medications. MB Store stocks water test kits, medicines and conditioners that help restore balance in the tank.

Overfeeding and poor diet can lead to obesity, constipation and fatty liver. A bloated, sluggish fish with reduced activity is a sign that the feeding regime must be adjusted. Introduce fasting days (e.g., once a week), reduce portion sizes and feed more diversified foods. Walking catfish are masters at begging for food, but it is better to withstand their pleading behaviour than risk long-term health problems.

Ensuring good oxygenation and clean water is essential, even though the fish can breathe air. Accumulated organic waste increases ammonia and nitrite levels, which are toxic. A high-performance filter, regular vacuuming of the substrate and at least weekly water changes (20–30%) should become routine. Use water conditioners to neutralise chlorine and heavy metals. Equipment from MB Store, such as siphons, conditioners and professional filters, greatly simplifies these tasks and makes them more efficient.

Long-term care also includes regular observation. Pay attention to the fish’s appetite, swimming style, interaction with tank mates and response to stimuli. A healthy walking catfish is active, curious, feeds eagerly and explores the environment. Any sudden changes – lethargy, hiding, staying near the surface or bottom for long periods, rubbing against decorations – should raise questions. Early intervention often means the difference between quick recovery and serious illness.

Finally, do not forget mental stimulation. Clarias batrachus is intelligent and can become bored in monotonous conditions. Periodic rearrangement of decorations, introduction of new hiding places, variation of food types and interactive feeding (e.g., offering food with tweezers in different areas) provide enrichment. This not only makes life more interesting for the fish, but also allows the aquarist to observe a wider range of natural behaviours, turning everyday care into a more rewarding experience.

MB Store – Reliable Support for Keeping Walking Catfish

Deciding to keep a walking catfish means entering the world of large, demanding aquarium fish. To meet their requirements, you need not only knowledge and patience, but also reliable equipment. MB Store offers a wide selection of aquariums with secure lids, powerful filters, heaters, lighting systems and practical accessories. With this infrastructure, you can create a stable environment in which Clarias batrachus will thrive rather than simply survive.

When choosing an aquarium, pay attention to dimensions and lid design. MB Store staff can help you select a tank that provides enough swimming space and allows integration of all necessary devices. Special attention is paid to safe covers, which are crucial in the case of species that can escape. You can also find complete sets that combine tank, filter, lighting and heater – a good starting point for those building a system dedicated to walking catfish.

The right filter and heating system guarantee clean water and stable temperature. MB Store offers external canister filters, internal filters and modern heaters with precise thermostats. With their help, maintaining optimal conditions (temperature around 24–28 °C, appropriate pH and hardness) becomes much simpler. For a species that produces as much waste as the walking catfish, effective filtration is not a luxury but a necessity.

Beyond hardware, MB Store provides foods, conditioners, medicines and testing kits. This allows you to create a complete care system – from everyday feeding to reacting to unforeseen problems. Educational materials and staff experience support aquarists at every stage: from planning the first large tank to long-term maintenance of a complex system with demanding predators.

Keeping a walking catfish is not for everyone, but for those who are ready, it can become a fascinating adventure. With proper preparation, responsible approach and support in the form of suitable aquariums and equipment, this impressive fish will reward its keeper with behaviour and interactions that you will not experience with typical community species. MB Store stands ready to assist you in every step of this advanced fishkeeping journey.

FAQ – Walking Catfish in the Aquarium

Is the walking catfish suitable for beginners?
For most beginners, walking catfish is not recommended. It grows large, needs a spacious tank, solid filtration and a well-secured lid. Its predatory nature makes choosing tank mates difficult. It is better to gain experience with smaller, peaceful fish first, and consider Clarias batrachus only when you understand water chemistry and advanced care.

Can I keep walking catfish with other fish?
Yes, but only with large, robust species that will not fit into its mouth and can withstand more energetic behaviour. Avoid small fish, shrimps and delicate species. Provide many hiding spots and visual barriers. Even then, some risk remains, especially at night when the walking catfish hunts. A single-species tank is often safer and easier to manage.

Do I need a special lid for the aquarium?
A secure lid is absolutely essential. Walking catfish can push up loose covers and squeeze through small gaps near cables or equipment. Choose a lid that fits tightly and secure openings with sponges or dedicated covers. Many aquariums from MB Store include well-fitted lids that significantly reduce the risk of escapement and injury to the fish.

What should I feed my walking catfish?
Offer sinking pellets for carnivorous or omnivorous fish as the main diet, supplemented with frozen foods like shrimp, fish fillet or bloodworms. Occasionally add live foods and plant components, such as spirulina pellets or blanched vegetables. Feed moderately, once or twice a day, and remove leftovers to protect water quality and prevent obesity.

Is keeping walking catfish legal everywhere?
No. In some regions, especially where Clarias batrachus is invasive, laws restrict its import, sale or keeping. Always check local regulations before purchase by contacting authorities or consulting up-to-date online resources. Never release unwanted fish into wild waters. If you must rehome a specimen, use stores, clubs or experienced aquarists instead.