Brochis spp. – Brochis spp.

Among the peaceful bottom-dwellers kept by aquarists, Brochis spp. are a fascinating yet often overlooked group. Closely related to the well-known Corydoras, these armored catfish combine a calm temperament with active, almost playful behavior. They are ideal for community aquariums and for aquarists who appreciate natural biotopes, subtle colors and interesting group dynamics. In this article we will look at their origin, care requirements and how to keep them healthy and active in a home aquarium.

Taxonomy and natural distribution of Brochis spp.

Brochis are South American armored catfish that for a long time were considered a separate genus. In many modern taxonomic works they are included in the genus Corydoras, but in aquaristics the name Brochis is still widely used because it emphasizes some distinct features of these fish. They belong to the family Callichthyidae, the same family as the classic Corydoras and Dianema.

In the wild, Brochis live mainly in slow-flowing tributaries of large rivers such as the Amazon and its basin. They are found in shallow floodplain areas, muddy banks, and regions with dense aquatic or riparian vegetation. The water is often slightly stained with tannins from leaves and wood, with a soft to moderately hard profile and a typically neutral to weakly acidic pH.

The key feature that separates Brochis spp. from many Corydoras species is the noticeably higher number of dorsal fin rays. This gives the dorsal fin a taller, more triangular appearance. Their body shape is somewhat more robust, and many species show a metallic green or bluish shimmer that makes them very attractive in the right lighting.

Several species appear in the aquarium trade, among which the best known are Brochis splendens (often sold under different common names) and closely related green “Corydoras” forms. Due to taxonomic changes, the exact scientific names may differ depending on the literature, but from a care perspective, their requirements remain similar.

Appearance and behavior in the aquarium

Brochis spp. are medium-sized armored catfish. Many specimens reach 7–9 cm in length, which makes them slightly larger than most common Corydoras. Their body is covered with bony plates that provide protection, and the head is slightly more elongated, with well-developed barbels used for constant searching of food in the substrate.

The coloration of the best-known forms ranges from olive green to intense metallic green with bluish reflections, especially under high-quality aquarium lighting. The belly tends to be lighter, sometimes with golden reflections. Fins are usually transparent or slightly tinted, but in healthy and well-fed fish the back and flanks shimmer intensely, creating a very attractive effect in a planted aquarium.

Their behavior is typically peaceful. Brochis are gregarious fish: they feel best in groups and show natural behavior when kept in numbers of at least 5–6 individuals, preferably more. In a group they move in loose shoals, explore the bottom together, and sometimes suddenly dash to the surface to take a gulp of air. This is normal and related to their ability to use the intestine as an auxiliary respiratory organ.

Unlike many shy bottom fish, Brochis are active even during the day, especially in aquariums with subdued lighting and enough hiding places. They rarely disturb other species; at most they may gently nudge tank mates while searching for food. Because of their calm temperament, they are excellent for community tanks with small, peaceful fish such as tetras, rasboras and dwarf cichlids.

Setting up the ideal aquarium for Brochis spp.

To keep Brochis successfully, it is useful to recreate, as far as possible, the conditions of their natural habitat. A well-designed aquarium will not only ensure their health, but will also allow them to display their most interesting behavior patterns.

Aquarium size is an important starting point. For a group of 6–8 Brochis, a tank with a base of at least 80–100 cm in length is recommended. While they do not require great height, they appreciate a large bottom area, as they spend most of their time in the lower regions. A capacity from 100 liters upwards allows for stable water parameters and space for decoration and plants.

Substrate choice is crucial. Brochis constantly sift sand or fine gravel through their mouths in search of food. A sharp or coarse substrate can easily damage their sensitive barbels, which can lead to infections and feeding problems. Ideally, use fine, rounded sand or very smooth, small-grain gravel. Light-colored sand emphasizes their metallic green color beautifully and lets you observe their natural foraging behavior.

Decoration should offer both open areas and shaded zones. Roots, branches and natural driftwood create shelter and visual barriers that help reduce stress. Stones can be used, but edges should be rounded. Leaf litter (catappa leaves, oak or beech prepared for aquariums) not only provides hiding places and a more natural look, but also releases tannins that slightly color the water and can have a mild antibacterial effect.

Plants are highly recommended. Brochis do not damage healthy plants and are at most able to uproot very delicate species while digging. Robust rooted plants such as Echinodorus, Cryptocoryne, or various stem plants create shaded zones and stability. Floating plants reduce light intensity and give the aquarium a more “blackwater” ambiance, close to many South American habitats.

Filtration and water movement should ensure good oxygenation and clean water, but without creating a strong current directly on the bottom. A well-dimensioned internal or external filter with gentle flow is ideal. It is important that the intake of the filter is protected with a sponge or a guard to avoid barbels or small fish being sucked in. Brochis appreciate clean, well-oxygenated water; efficient biological filtration and regular maintenance are therefore essential.

MB Store offers a wide choice of aquariums, external and internal filters, heaters and other aquarium equipment that allows aquarists to design an ideal environment for Brochis and other community fish. When planning a setup, it is worth considering the dimensions of the tank, the type of filter and the substrate from the beginning, so that the bottom zone is safe and comfortable for these catfish.

Water parameters and compatibility

Brochis spp. are relatively tolerant of a range of water parameters, which makes them accessible even to intermediate aquarists. However, stable and appropriate values greatly increase their lifespan and vitality.

Temperature should typically be kept between 23 and 27 °C. Short-term deviations are usually tolerated, but permanent temperatures above 28 °C are not recommended, as they can accelerate metabolism and shorten life expectancy. On the other hand, temperatures constantly below 22 °C may weaken the immune system.

pH is best between 6.0 and 7.5. Slightly acidic water is closer to their natural habitats, but these fish can adapt well to neutral values, as long as changes are not sudden. Extreme pH values beyond this range should be avoided.

Water hardness can vary from soft to medium-hard. General hardness (GH) around 3–12 dGH and carbonate hardness (KH) in the lower to medium range are usually well tolerated. More important than exact values is the absence of ammonia and nitrite and keeping nitrate at a low to moderate level through regular water changes.

Water quality must be high. Brochis are quite sensitive to nitrogenous wastes and to abrupt changes. A regular regime of partial water changes, around 25–30% weekly, helps keep parameters stable and reduces organic load. When using tap water, it is necessary to treat it with a suitable conditioner to neutralize chlorine, chloramine and heavy metals.

Compatibility with other fish is one of the great advantages of Brochis spp. They are peaceful, non-territorial and do not harm plants or invertebrates larger than their mouth. Ideal tank mates include:

• Small peaceful characins (neon tetras, glowlight tetras, rummynose tetras)
• Rasboras and small danios that occupy upper and mid water layers
• Dwarf cichlids such as Apistogramma and Mikrogeophagus, provided they are not overly aggressive
• Other peaceful catfish like smaller Corydoras species or Otocinclus, if the aquarium size allows

It is advisable to avoid combining Brochis with large or aggressive fish, such as many large cichlids, predatory species or very active and nippy barbs. These can harass or stress bottom dwellers, limiting their access to food and reducing their active behavior.

The presence of other peaceful fish contributes to a sense of security for Brochis. In a well-planned community tank, you will observe more natural interactions, such as groups of Brochis exploring the bottom while shoals of tetras swim above them, creating a dynamic and harmonious scene.

Feeding and nutritional needs

In nature, Brochis spp. feed primarily on small invertebrates, insect larvae, worms and organic detritus found in the substrate. In the aquarium, they adapt easily to prepared food, but to maintain optimal health and coloration it is worth paying attention to variety and quality.

Base diet can be composed of sinking pellets or tablets formulated for catfish and bottom feeders. Choose products that contain high-quality protein sources and added vitamins. Pellets designed for Corydoras or omnivorous bottom species are usually suitable and easy to distribute along the substrate, allowing all individuals in the group to feed.

Frozen and live foods are excellent supplements that stimulate natural foraging behavior and improve overall condition. Offer bloodworms (in moderation), black mosquito larvae, daphnia, cyclops or finely chopped tubifex. It is important to avoid relying exclusively on very fatty foods and to ensure they come from safe, controlled sources to reduce the risk of introducing pathogens.

Vegetable components also play a role in a balanced diet. While Brochis are primarily carnivorous, they will accept tablets with vegetable content, spirulina, and some blanched vegetables such as zucchini or peas (without skin). These ingredients help digestion and provide additional micronutrients.

Feeding frequency should be adapted to the size of the group and the presence of other species in the aquarium. Generally, two moderate feedings per day are sufficient. A common mistake is to assume that Brochis “clean” the bottom and can live only on leftovers from other fish. This leads to malnutrition and weakening. They must receive dedicated food that reaches the substrate.

When feeding, observe if all fish manage to access the food. Brochis are peaceful and can be outcompeted by fast mid-water species. Distributing tablets in different areas of the aquarium and feeding when lights are slightly dimmed can help ensure that every individual receives its share.

To complement the dietary strategy, MB Store offers a wide range of high-quality dry, frozen and specialized foods. Selecting appropriate formulations for bottom feeders and alternating them intelligently over the week promotes strong immunity, intense coloration and a more active, confident behavior in Brochis spp.

Social structure, health and breeding

Brochis are social fish, and their well-being is closely linked to group size. Keeping them in pairs or in very small numbers often results in shy, inactive fish that spend most of their time hiding. In contrast, a group of 6–10 individuals displays coordinated movements, collective foraging and even subtle dominance interactions that are harmless and interesting to observe.

Social behavior within the group is typically peaceful. Occasionally, two individuals may briefly “push” each other with their snouts or take parallel positions, but these behaviors rarely escalate. A well-structured aquarium, with hiding places and a sufficiently large bottom area, prevents any tension and allows more submissive fish to withdraw when they wish.

Health of Brochis spp. depends primarily on water quality, adequate diet and proper substrate. The barbels are a sensitive point: if they are shortened, frayed or missing, this often indicates abrasive or dirty substrate, high levels of organic waste or bacterial infections. Maintaining cleanliness, avoiding sharp gravel and regularly vacuuming the bottom (without over-disturbing the sand) are key preventive measures.

Common problems also include stress-related diseases, such as susceptibility to external parasites, when fish are exposed to sudden parameter changes or kept with aggressive tank mates. Quarantine of new fish and plants, along with careful introduction procedures, helps prevent the introduction of pathogens into an established aquarium.

Breeding Brochis spp. is possible in captivity, though it is somewhat less common than breeding of some Corydoras species. The basic principles, however, are similar. To encourage spawning, you will need a healthy group with both sexes present, ideally with well-conditioned fish fed intensively with live and frozen foods over several weeks.

Spawning is often stimulated by water changes with slightly cooler and softer water, simulating the onset of the rainy season in their natural environment. Lowering the temperature by 1–2 °C and performing a larger water change can trigger courtship behaviors. Males will begin to follow and nudge females, and the typical “T-position” may be observed, similar to the behavior of Corydoras.

Females deposit sticky eggs on glass, plants or deco elements, usually in small groups. Parents often do not guard the eggs; on the contrary, they may sometimes eat them. For this reason, many breeders move the eggs or breeding pair to a separate, specially prepared aquarium with gentle aeration and identical water parameters.

Raising fry requires attention to water cleanliness and access to very small foods. Newly hatched fry first consume their yolk sac, then can be fed with infusoria, liquid fry foods, and later with freshly hatched Artemia nauplii or microworms. Frequent small water changes and diligent removal of uneaten food are essential to prevent disease outbreaks.

Successful breeding is a sign that the aquarium environment is well balanced and that the group of Brochis is thriving. Even if you do not intend to become a breeder, understanding the reproductive needs of these fish helps you better recognize signs of good or poor condition and adjust your care accordingly.

Brochis spp. in the broader context of aquariums and fishkeeping

Including Brochis spp. in an aquarium project means not only adding an attractive species, but also diversifying the ecological roles within the system. As active bottom foragers, they contribute to the breakdown of leftover food and the gentle stirring of the top substrate layer. Although they are not “cleaners” in the strict sense, their natural behavior helps prevent the accumulation of debris in hard-to-reach areas.

In a community aquarium, Brochis occupy the lower region, complementing mid- and upper-water species. This vertical distribution allows aquarists to create multi-layered scenes where each group of fish uses a different niche. This is interesting both aesthetically and educationally, especially for those who approach aquaristics as a way to observe natural behaviors and interactions.

From a design perspective, Brochis are particularly well suited to biotope-inspired aquariums that mimic South American streams and floodplain areas. The combination of fine sand, driftwood, leaf litter and soft lighting creates a natural look in which these armored catfish feel at home, showing their full color and more confident behavior.

Fishkeepers who prioritize stability, welfare and naturalistic setups often appreciate species such as Brochis because they reward patience and careful planning. Rather than being a “show” fish with extravagant fins or bright colors, they impress through subtle metallic tones, group dynamics and their constant, methodical exploration of the bottom.

When planning such an aquarium, MB Store can be a strategic partner, offering not only tanks in various sizes and formats, but also the necessary filtration, lighting, heating, substrates and decorative materials. With suitable equipment and well-chosen accessories, both beginners and experienced aquarists can create stable ecosystems in which Brochis spp. and their tank mates thrive for many years.

Ultimately, adding Brochis to an aquarium is an invitation to observe details: how they interact with each other, how they explore every corner in search of food, how they quickly rise to the surface for a breath of air and immediately return to the bottom. These behaviors remind us that, even in a glass box, fish retain much of their natural repertoire, and that responsible fishkeeping is about offering conditions in which these instincts can be expressed fully.

FAQ – Brochis spp. in the aquarium

Are Brochis spp. suitable for beginners?
Yes, Brochis can be kept by beginners who understand the basics of the nitrogen cycle and regular maintenance. They are robust if water is clean and substrate is fine. A group of at least 6 fish, stable temperature, and appropriate filtration are essential. Avoid sharp gravel and aggressive tank mates to prevent stress and injuries.

How many Brochis should I keep together?
Brochis are shoaling fish and should be kept in groups of at least 5–6 individuals, preferably more if tank space allows. In small numbers they become shy and hide often. A larger group spreads out stress, promotes natural behaviors and creates impressive group movements along the bottom, especially in spacious aquariums.

Do Brochis clean the aquarium bottom?
Brochis help consume leftover food on the substrate, but they are not a substitute for proper maintenance. They still produce waste and need regular water changes and substrate vacuuming. Think of them as active bottom foragers, not cleaning tools. Overfeeding, even with Brochis present, will still lead to poor water quality over time.

Can Brochis live with shrimp and snails?
In general, adult shrimp and medium-sized snails are safe with Brochis, as these catfish do not actively hunt them. Very small shrimplets might occasionally be eaten if they fit in the mouth. Providing dense plants, mosses and hiding spots helps protect young shrimp. Stable parameters and gentle filtration favor invertebrate health.

What is the ideal substrate for Brochis?
The best substrate is fine, rounded sand or very smooth small-grain gravel. Brochis constantly sift substrate through their mouths, and sharp gravel can damage their delicate barbels, leading to infections. Light-colored sand highlights their metallic green sheen and encourages natural digging behavior, making them more active and confident.