Scrapermouth Mbuna – Labeotropheus trewavasae

The Scrapermouth Mbuna, scientifically known as Labeotropheus trewavasae, is one of the most distinctive cichlids from Lake Malawi. Its unusual mouth shape, intense colors and dynamic behavior make it a fascinating resident for Malawi biotope aquariums. At the same time, it demands thoughtful care, stable water parameters and a well-planned tank layout. In this article we will explore how to keep this mbuna successfully, what to feed it and how to combine it with other fish, so that your aquarium remains both beautiful and stable. Throughout, remember that MB Store offers a wide range of aquariums and aquarium equipment that can help you create an ideal environment for this species.

Origin and natural habitat of Labeotropheus trewavasae

Labeotropheus trewavasae belongs to the group of rock-dwelling cichlids from Lake Malawi known as mbuna. The term “mbuna” in the local language describes fish that live “among the stones,” which already reveals a lot about their ecological niche. This species inhabits the rocky coastal zones, where powerful waves and currents constantly wash the boulders and cliffs, creating ideal conditions for the growth of algae and microorganisms. These algae layers are the primary feeding ground for the Scrapermouth Mbuna.

The characteristic feature of Labeotropheus trewavasae is its uniquely shaped mouth. The upper lip extends forward like a pad and, combined with a steep forehead profile, allows the fish to precisely scrape off algae from rock surfaces. In the wild, it spends most of its time close to rocks, continuously grazing on so-called aufwuchs – a mixture of filamentous algae, diatoms, cyanobacteria and tiny crustaceans. This natural diet and behavior are crucial to understand when planning a captive environment.

Lake Malawi is famous for its crystal-clear, mineral-rich waters. The basic water parameters in the natural habitat of Labeotropheus trewavasae are:

• Temperature: approximately 24–27 °C
• pH: around 7.8–8.6 (strongly alkaline)
• Hardness: medium to hard, rich in dissolved minerals

The species shows some geographic variation, and aquarists often distinguish between different locality forms, such as “Thumbi West,” “Chilumba” or “Lion’s Cove,” each with somewhat distinctive body and fin colors. These forms should not be mixed in the same aquarium if you want to avoid hybridization and preserve their natural appearance.

By replicating rocky environments, strong lighting for algae growth and stable, alkaline water, we can create an aquarium that allows this fish to express its natural behavior. Here is where proper equipment, such as robust filtration, dedicated lighting and appropriately sized tanks available at MB Store, becomes essential.

Appearance and sexual dimorphism

The Scrapermouth Mbuna stands out not only because of its mouth, but also because of its compact body and dynamic coloration. Adult size usually reaches 10–13 cm, rarely more under aquarium conditions. The body is elongated, slightly laterally compressed, giving the fish an agile and powerful look suitable for swift maneuvering through rock crevices.

The head profile is steep, ending in the characteristic protruding upper lip. This adaptation gives Labeotropheus trewavasae a somewhat “bulldog-like” appearance that many aquarists find charming. The dorsal fin typically extends almost the entire length of the back, while the caudal fin is slightly rounded, providing both speed and precision of movement.

Coloration can vary widely depending on the locality form and sex. In many forms, males display vivid shades of blue, turquoise or blue-green over the body, sometimes with a contrasting orange or red band along the dorsal fin or on the shoulders. Some variants show warm orange or rusty red on the belly or lower flanks, creating a spectacular contrast. Females, on the other hand, are usually more modestly colored, often in various shades of brown, gray, beige or light blue, sometimes with faint vertical barring.

Sexual dimorphism is visible not only in coloration but also in body shape. Males tend to be more robust, with more extended fins and more intense, saturated colors. In many cases they also develop more pronounced egg spots (ocelli) on the anal fin. Females often remain smaller and more rounded. However, in some locality forms, subdominant males may adopt female-like coloration to avoid aggression from dominant males, which can make sexing more challenging for less experienced aquarists.

When purchasing Labeotropheus trewavasae, it is wise to select a group of juveniles and let them grow together. Over time, natural hierarchies will form and males will develop their adult coloration. MB Store can help you with appropriately sized and well-equipped tanks to support such growth, providing both filtration and lighting suited for Malawi cichlids.

Tank size and layout for Scrapermouth Mbuna

Proper tank design is the foundation for successfully keeping Labeotropheus trewavasae. Despite their relatively modest size, these fish are active, territorial and require adequate swimming space combined with plenty of rock structures. Keeping them in tanks that are too small or bare increases aggression and stress, and can significantly reduce their lifespan.

For a small harem group – one male and three to five females – the absolute minimum tank volume is around 200 liters, but more is always better. A longer tank (for example 100–120 cm in length or more) works far better than a high but short aquarium, as it creates more distinct territories and swimming space. If you plan to keep Labeotropheus trewavasae together with other mbuna species, consider tanks from 300 liters upwards to distribute aggression.

Rockwork is the main structural element for this species. Use stable piles of stones that reach up towards the water surface, creating caves, crevices, tunnels and ledges. The goal is to provide both physical barriers and visual breaks – so that subordinate fish can move away from dominant individuals and disappear from their field of view. Arrange the rocks in a way that prevents collapses; you can support them with egg-crate under the substrate or silicon some critical stones together if needed.

Substrate should ideally be sand or fine gravel with light coloration, reminiscent of the natural rocky shores of Lake Malawi. Sand also allows the fish to display some natural digging behavior. Darker substrates can enhance the colors of the fish, but very dark backgrounds sometimes increase perceived aggression because contrasting silhouettes are more visible. A balanced approach is often best.

Lighting plays an important role. Stronger lighting enhances the visual effect of the rock structures and fish coloration, but also promotes algae growth on the stones, which is welcome for a naturalistic Malawi setup. Labeotropheus trewavasae will graze continuously on these algae films. However, excessive algae on the glass or equipment can be controlled with proper maintenance. MB Store offers lighting systems designed for freshwater aquariums, allowing you to choose a spectrum that highlights blues and oranges while supporting plant or algae growth where desired.

Filtration must be robust. Mbuna are active and produce a significant amount of waste. Aim for a filter turnover of at least 5–7 times the aquarium volume per hour. External canister filters, internal power filters or a combination of both are common choices. Additional aeration, such as air stones or surface skimmers, ensures a high oxygen level, especially important at higher temperatures. MB Store provides various filter solutions and accessories to help maintain excellent water quality.

While live plants are usually not typical of rocky Malawi biotopes, some hardy species like Anubias, Java fern or Vallisneria can be used, preferably attached to rocks. Yet, keep in mind that many mbuna will nip at soft leaves. In a pure mbuna setup, the rockwork itself becomes the primary decorative and functional element.

Water parameters and maintenance

Labeotropheus trewavasae, like other Lake Malawi cichlids, thrives in stable, alkaline and mineral-rich water. Sudden fluctuations in temperature, pH or hardness can lead to stress and disease, so consistent maintenance practices are essential.

Target water parameters should be:

• Temperature: 24–26 °C (can be slightly higher, but stability is key)
• pH: 7.8–8.4, slightly above neutral and clearly alkaline
• General hardness (GH): 8–15 °dGH
• Carbonate hardness (KH): 7–12 °dKH

If your tap water is naturally soft or slightly acidic, you may need to use mineral salts, limestone rock, aragonite sand or commercial Malawi buffers to raise and stabilize KH and pH. Avoid sudden corrections; make any changes gradually. MB Store offers water conditioners, test kits and buffering agents that can simplify this process and keep your parameters within the desired range.

Regular water changes are non-negotiable. With active cichlids that produce considerable bioload, weekly water changes of 25–40% are recommended. Larger, less frequent changes can work in heavily filtered tanks, but most aquarists find that smaller, consistent changes improve fish health and coloration. Always match the temperature of the fresh water to that in the tank as closely as possible and pre-condition it with dechlorinators if your tap water contains chlorine or chloramine.

Monitoring nitrogen compounds is crucial. Ammonia and nitrite should always be at 0 mg/l, while nitrate should ideally remain below 20–30 mg/l. In a heavily stocked Malawi tank this can be challenging, but good filtration and regular changes help keep nitrate under control. Frequent vacuuming of detritus from the substrate, especially in less flowed areas, further prevents accumulation of organic waste that might deteriorate water quality over time.

Due to the high pH, heavy metal toxicity can increase, so using quality conditioners that neutralize metals and protect the mucous membranes of fish is recommended. UV sterilizers can be an optional extra, especially in larger show tanks, to reduce free-floating algae and pathogens. Many of these systems and accessories can be found in MB Store’s range of equipment, helping you maintain clear water and healthy fish.

Water stability also depends on avoiding overfeeding. Because mbuna are constantly active and appear hungry, there is a strong temptation to feed them excessively. This not only pollutes the water, but also increases the risk of digestive problems such as Malawi bloat, a dangerous condition particularly associated with inappropriate diet and poor water quality.

Feeding the specialized scrapermouth herbivore

The name Scrapermouth Mbuna perfectly reflects the feeding strategy of Labeotropheus trewavasae. In nature, this fish spends most of its day scraping algae and associated microorganisms from rocks. This makes it, first and foremost, an herbivore with a digestive system adapted to a fiber-rich diet, even though it does consume small invertebrates incidentally.

In the aquarium, the main diet should consist of quality herbivorous or omnivorous cichlid foods with a strong emphasis on plant ingredients. Flakes and pellets formulated specially for Malawi mbuna typically contain spirulina, various algae and vegetable components. Look for foods where fish meal is not the dominant ingredient and where there is a good proportion of plant-based proteins. High-quality sinking or floating pellets from reputable brands, many of which are available through shops like MB Store, form the basis of a balanced feeding regime.

Supplement this base with fresh or blanched vegetables. Popular choices include:

• Blanched spinach or lettuce (in moderation)
• Zucchini or cucumber slices weighted down on a rock
• Peas (peeled), offered occasionally
• Spirulina-enriched wafers

Such additions provide extra fiber and mimic the roughage content of their natural diet. The key is not to leave uneaten vegetables in the tank for too long, as they can decompose and pollute the water. Remove any leftovers after several hours.

Animal protein should be given sparingly. Avoid high-protein, fatty foods like beef heart or large quantities of bloodworms, which are more suitable for carnivorous species. Overconsumption of such foods is linked to digestive issues and the dreaded Malawi bloat. If you wish to provide some animal protein, occasional small portions of high-quality krill-based pellets or a bit of frozen mysis shrimp can be tolerated, but these should not form the core of the diet.

Feed small amounts multiple times a day rather than one large feeding. Mbuna are natural grazers; two to three feedings per day, each lasting only a few minutes, are usually optimal. Observe the fish: a slightly rounded but not distended belly indicates they are well-fed. Overfed fish become lethargic and more susceptible to disease.

By combining specialized herbivore foods, fresh vegetables and algae growth encouraged on rocks by good lighting, you can create a very natural and healthy feeding environment. This supports bright coloration, proper growth and robust immunity. Here, the right lighting and water stability, assisted by products from MB Store, reinforce the benefits of a thoughtful diet.

Social behavior, aggression and tank mates

Labeotropheus trewavasae is a typical mbuna in terms of temperament: active, territorial and often quite assertive, especially males. Understanding this social behavior is key to avoiding conflicts and ensuring a relatively peaceful community aquarium.

In the wild, males claim territories on rock faces, defending them from rival males and courting females who pass through. In the aquarium, similar behavior emerges. The dominant male will typically choose a specific rocky area and patrol it, displaying to intruders and chasing them away. To manage this aggression, it is best to keep this species in a harem structure, with one male per several females. This spreads the male’s attention and reduces harassment of any single female.

Keeping more than one male in smaller tanks often leads to constant fighting, fin damage and chronic stress. In larger aquariums (300 liters or more) with complex rockwork and multiple visual barriers, it is sometimes possible to maintain two or more males, but this remains a strategy for experienced aquarists who can closely monitor interactions and adjust the stocking if necessary.

Tank mates should be chosen among other robust mbuna species with similar dietary and environmental requirements. Good companions may include species of Pseudotropheus, Labidochromis or Metriaclima, provided they are not too similar in color and pattern to avoid hybridization and excessive interspecific competition. It is usually better to avoid mixing Labeotropheus trewavasae with species that occupy exactly the same ecological niche or have very similar body shape and coloration, as this tends to intensify aggression.

Fish that are too peaceful or slow – such as many South American cichlids, angelfish, or soft-water community fish – are not suitable tank mates. They will be stressed or injured by the energetic mbuna. Likewise, fin-nipping behavior of mbuna can damage long-finned species. A Malawi tank is best thought of as a specialized environment for African cichlids with hard, alkaline water, rather than a general community aquarium.

Overstocking is sometimes used as a method of aggression management in mbuna tanks: keeping a relatively high number of similar-sized fish distributes aggression among many individuals. While this can work, it places greater demands on filtration and water changes. MB Store’s range of efficient filters, aeration systems and larger aquariums can support such setups, but it remains important to avoid extremes. Balance between stock density and technical capacity is crucial.

Ensure numerous hiding places and visual barriers among the rocks so that subordinate fish can escape direct line of sight from dominant individuals. Observing the dynamics within the group can be fascinating: the constant displays, subtle color changes and courtship rituals form an integral part of the charm of keeping Labeotropheus trewavasae.

Breeding Labeotropheus trewavasae in the aquarium

Labeotropheus trewavasae is a maternal mouthbrooder, like many other Lake Malawi cichlids. This means the female carries the fertilized eggs, and later the fry, in her mouth for a certain period, protecting them until they are ready to swim freely. Breeding in a well-maintained aquarium is usually not very difficult and can even happen spontaneously once the fish are mature and comfortable.

Sexual maturity is typically reached at around 8–10 cm, depending on nutrition and conditions. A dominant male will choose a territory, often a flat stone or a small cave where he can display to females. Courtship displays include intense coloration, body quivering and leading the female to the chosen spawning site. Once a receptive female follows, the pair circles in tight patterns while eggs are laid and immediately taken into the female’s mouth.

The male fertilizes the eggs using the egg spots on his anal fin as a cue: the female, attempting to pick up these “eggs,” takes in sperm that then fertilizes the real eggs already in her mouth. This fascinating adaptation ensures successful external fertilization within the confines of mouthbrooding.

The incubation period lasts around 21–28 days, during which the female eats little or nothing and tends to remain more secretive. Her buccal cavity appears enlarged, and she may show less interest in interaction. Many aquarists choose to leave the brooding female in the main tank, allowing natural release of fry. Others prefer to gently move her to a separate nursery tank near the end of the incubation period to protect the fry from predation.

When the fry are ready, the female releases them gradually. In a well-structured tank with plenty of rockwork and crevices, some fry may survive even in a community setting, but many will become prey to other mbuna, including their own parents. To maximize survival, raising them in a dedicated fry tank is recommended. There, they can be fed finely crushed herbivorous flakes, specialized fry foods and later small pellets.

Water conditions for fry should mirror those of the adults, but extra attention must be paid to cleanliness and avoiding strong currents that might exhaust the tiny fish. Frequent small water changes, stable temperature and finely tuned filtration are vital. MB Store’s selection of small sponge filters, gentle pumps and appropriately sized aquariums can be very useful for setting up such nursery systems.

One important ethical consideration is avoiding uncontrolled breeding if you lack space or outlets for juvenile fish. Mbuna breed prolifically under good conditions, so have a plan for rehoming or trading fry in advance. Additionally, never intentionally cross different mbuna species or locality forms for the sake of “new” color variants; this practice diminishes the genetic purity of these fish, which are often highly localized in the wild.

Key equipment and how MB Store can help

Creating an ideal environment for Labeotropheus trewavasae requires a thoughtful choice of technical equipment and accessories. While experience and careful observation are crucial, having reliable tools greatly simplifies daily maintenance and ensures long-term stability.

The starting point is an appropriately sized aquarium. Tanks in the 200–300 liter range or larger provide the necessary space for a group of Scrapermouth Mbuna and compatible species. The glass thickness, stand strength and overall construction must be sufficient to safely bear the weight of water, rocks and substrate. MB Store offers robust aquariums in various dimensions, allowing you to choose a model that fits both your living space and your fishkeeping ambitions.

Next comes filtration. For mbuna tanks, external canister filters are especially popular, as they offer significant biological and mechanical filtration volume, easy maintenance and the possibility of customizing media. Combining them with internal circulation pumps helps eliminate dead spots and ensures that oxygen-rich water reaches all regions of the tank. MB Store’s range of canister, internal and hang-on filters gives you flexibility in designing the right filtration strategy.

Heating is usually provided by adjustable submersible heaters. Even though many homes maintain temperatures not far from Malawi ranges, a reliable heater keeps the water stable, which is more important than the exact number on the thermometer. Always use a quality thermometer to verify the set temperature. In larger systems, using two smaller heaters instead of one big one can increase safety in case of failure.

Lighting, as mentioned earlier, is not only about aesthetics. For Labeotropheus trewavasae, well-planned lighting encourages healthy algae growth on rocks and brings out the vivid blues, oranges and reds of the fish. LED systems with adjustable intensity and color spectrum are now standard in many aquariums. MB Store provides modern lighting solutions suitable for Malawi biotopes, helping you achieve both visual impact and functional benefits.

Other useful equipment includes wave makers or circulation pumps to simulate the natural water movement around rocks, air pumps and stones for extra oxygenation, background foils or 3D backdrops that enhance the sense of depth and cover, and high-quality test kits for monitoring pH, hardness and nitrogen compounds. All of these tools help keep your system stable and allow Labeotropheus trewavasae to display its full potential.

Decor and substrate choices also count as “equipment” in a broader sense. Hard, inert rocks – such as limestone, tufa, granite or slate – serve both as shelter and as surfaces for algae growth. Sand or fine gravel replicate the natural setting and are gentle on the fish’s mouth and fins. When planning your layout, consider both biological needs and visual harmony: a well-designed rockscape not only pleases the eye but also reduces aggression by creating natural territorial boundaries.

Finally, basic maintenance accessories – nets, siphons, algae scrapers, buckets reserved for aquarium use – are everyday tools that make water changes and cleaning routine. Combining these with the right foods and supplements builds a complete system in which Scrapermouth Mbuna can live long, healthy lives. MB Store’s complete range of aquarium gear allows both beginners and advanced keepers to equip their setups fully and reliably.

Is Labeotropheus trewavasae right for you?

Deciding whether to keep Scrapermouth Mbuna depends on your expectations from the aquarium hobby and your willingness to engage with a somewhat demanding but incredibly rewarding group of fish. Labeotropheus trewavasae is not a fragile species, but it does require a certain level of commitment to water chemistry, aquascaping and social management.

If you are attracted to vivid colors, dynamic behavior and complex social interactions, and if you appreciate the idea of recreating a biotope that reflects a specific natural environment, then a Malawi mbuna tank featuring Labeotropheus trewavasae may be perfect. You should be prepared to invest in a sufficiently large tank, strong filtration and adequate lighting, as well as to perform regular water changes and parameter monitoring.

Beginners to aquarium keeping can certainly attempt this species, provided they are willing to study the basic principles of cichlid husbandry, understand the needs of herbivorous fish and avoid common pitfalls like overstocking without proper filtration, overfeeding and mixing incompatible species. Many aquarists actually start their “serious” fishkeeping journey with mbuna, quickly falling in love with their personalities and intense coloration.

On the other hand, if you prefer extremely calm community tanks with delicate plants, shrimp and soft-water fish, or if your tap water is very soft and acidic and you do not wish to modify it, Labeotropheus trewavasae may not be the best choice. These fish thrive in hard, alkaline water and will often damage finer plants. They also demand a rock-based layout rather than lush vegetation.

When planned carefully, a tank dominated by Scrapermouth Mbuna and other compatible mbuna species becomes a living, ever-changing landscape, full of color, movement and fascinating breeding behavior. With the right care, equipment and dedication, you can enjoy a thriving piece of Lake Malawi in your home. MB Store, with its selection of equipment, tanks and accessories, can support you in each step of designing, setting up and maintaining such a system, helping you transform interest into a stable, long-term success.

FAQ – Labeotropheus trewavasae (Scrapermouth Mbuna)

How big does Labeotropheus trewavasae get in the aquarium?
Adult Scrapermouth Mbuna typically reach 10–13 cm in length, with males often slightly larger and more robust than females. Growth rate depends on diet, water quality and tank size. In smaller or overcrowded tanks, growth can be stunted. Providing spacious, well-filtered aquariums helps them reach their full size and natural body shape.

Can I keep Labeotropheus trewavasae with other fish?
Yes, but tank mates must be chosen carefully. Best companions are other mbuna species from Lake Malawi that share similar water needs and assertive temperament. Avoid mixing them with peaceful community fish, soft-water species or long-finned varieties, as these will be stressed or injured. Ensure enough space and rock structures to manage territorial behavior.

What is the ideal diet for Scrapermouth Mbuna?
Provide a predominantly herbivorous diet based on high-quality mbuna flakes or pellets rich in algae and plant matter. Supplement with vegetables like blanched spinach, zucchini or peas. Limit animal proteins and avoid fatty foods such as beef heart. This approach supports healthy digestion, bright coloration and helps prevent Malawi bloat, a dangerous digestive disorder.

How do I tell males and females apart?
Males are usually more colorful, larger and have more extended dorsal and anal fins with pronounced egg spots. Females tend to be smaller, with brownish or grayish tones. However, subdominant males may temporarily mimic female coloration. Reliable sexing becomes easier as the fish mature and a clear hierarchy and coloration differences appear in the group.

Is Labeotropheus trewavasae suitable for beginners?
It can be kept by dedicated beginners who are willing to learn about hard, alkaline water, regular maintenance and the social dynamics of mbuna. A properly sized tank, strong filtration and appropriate diet are essential. Reading up on Malawi cichlid care and planning the setup thoroughly beforehand will greatly increase the chances of long-term success with this species.