Firemouth Cichlid Tank Mates – The Best and the Worst - "Thorichthys meeki - Wilhelma 01" by H. Zell is licensed under CC BY-SA 3.0.
Firemouth Cichlid Tank Mates – The Best and the Worst - "Thorichthys meeki - Wilhelma 01" by H. Zell is licensed under CC BY-SA 3.0.


Setting up an aquarium that houses firemouth cichlids presents a unique opportunity to observe the fascinating behaviors and vibrant colors of these freshwater fish. Known for their distinct fiery red undersides and relatively peaceful demeanor, firemouth cichlids can be a joy to keep. However, their territorial nature, especially during breeding periods, requires careful consideration when selecting firemouth cichlid tank mates to ensure a harmonious community tank. This guide aims to navigate the complexities of choosing compatible companions for firemouth cichlids, highlighting both suitable and unsuitable tank mates based on factors such as temperament, size, and environmental needs.

Appearance and Behavior

Firemouth cichlids are a vibrant and interesting species in the aquarium hobby, known for their distinctive appearance and behavior.


Firemouth cichlids (Thorichthys meeki) are medium-sized fish, typically reaching about 6 inches (15 cm) in length in captivity. They have a striking appearance, most notable for the bright red or orange coloring that extends from the underside of their jaw across their belly, which is more vivid in males. This fiery coloration is the origin of their common name, “firemouth.” Their bodies are elongated and somewhat laterally compressed, with a mix of blue, gray, and green hues that provide a beautiful contrast to their brighter underbellies. The scales often have a shimmering effect, adding to their visual appeal. Males tend to be larger and more colorful than females, with elongated dorsal and anal fins that are tipped with beautiful filamentous extensions.


Firemouth cichlids are known for their unique behaviors, particularly during breeding season. They are generally peaceful but can become territorial when spawning. Males display an interesting behavior where they flare their gills to show off their red throat and belly, intended to intimidate rivals and attract females. This gill-flaring can also be observed when they feel threatened or are asserting dominance within the tank.

These fish are substrate spawners, meaning they lay their eggs on flat surfaces like rocks or in dug-out pits in the sand. Both parents are involved in the care of the eggs and fry, exhibiting strong parental instincts. They will fiercely guard their spawn, becoming more aggressive towards tank mates during this time.

Outside of the breeding season, firemouth cichlids are relatively peaceful and can be seen engaging in typical cichlid behaviors such as digging in the substrate and exploring their environment. They are curious and can be quite interactive with their environment and even their human caretakers.

Firemouth cichlids are omnivorous, feeding on a variety of foods in captivity, including pellets, flakes, frozen, and live foods. Their diet can influence their color vibrancy, with a well-rounded diet leading to brighter colors.

Overall, firemouth cichlids offer a fascinating combination of beauty and behavior, making them a popular choice among aquarium enthusiasts. Their striking colors and engaging behaviors, especially during breeding, make them a captivating species to observe and care for.

Selecting Tank Mates

When selecting tank mates for firemouth cichlids, several important considerations must be taken into account to ensure a harmonious aquarium environment. Here are key factors to consider:

  • Compatibility: Choose species that have a compatible temperament with firemouth cichlids. Since firemouths can become territorial, especially during breeding, it’s important to select tank mates that are neither too aggressive to provoke them nor too timid to be bullied.
  • Breeding Behavior: Understand that firemouth cichlids become more aggressive during breeding. Tank mates should be able to withstand this temporary increase in territorial behavior.
  • Size: Opt for fish that are similar in size to firemouth cichlids. Smaller fish might be bullied or seen as prey, while much larger fish could intimidate or harm the firemouths.
  • Robustness: Choose robust and fast-swimming fish that can hold their own without being aggressive.
  • Water Parameters: Ensure that potential tank mates require similar water conditions as firemouth cichlids. This makes it easier to maintain an environment that’s healthy for all inhabitants.
  • Environmental Needs: Consider the environmental preferences of potential tank mates, such as plants, hiding spots, and substrate, to match the needs of firemouth cichlids.
  • Feeding Habits: Select fish with similar dietary needs to avoid competition for food. Firemouth cichlids are omnivorous, so tank mates with similar omnivorous diets are usually a good match.
  • Activity Patterns: Consider the activity level and swimming patterns of potential tank mates. Species that occupy different levels of the tank can help avoid territorial disputes and ensure more peaceful coexistence.
  • Observation: After introducing new tank mates, closely monitor the tank to ensure that all fish are getting along without signs of stress or aggression.
  • Space: Provide ample space and hiding places to reduce territorial behavior. A larger tank can help minimize conflicts and stress among inhabitants.

By carefully considering these factors, you can create a balanced and peaceful aquarium environment that is beneficial for firemouth cichlids and their tank mates.

The Best Tank Mates for Firemouth Cichlids

Selecting good firemouth cichlid tank mates involves finding species that can coexist peacefully with them, taking into account the firemouth’s territorial behavior during breeding. Here is a refined list that encompasses a variety of fish that can make suitable companions, ensuring a harmonious tank environment:


  • Angelfish (Pterophyllum scalare): With their peaceful nature and large size, they can hold their own in a community tank without becoming aggressive towards firemouths, provided there’s ample space.
  • Ram cichlids (Mikrogeophagus ramirezi): Their peaceful demeanor and smaller size make them a good match in a well-structured tank with hiding places, as long as care is taken to ensure they are not outcompeted for food.

Larger Tetras

  • Black skirt tetra (Gymnocorymbus ternetzi): These larger tetras are less likely to be bullied and can add activity to the middle and upper levels of the tank.
  • Bleeding heart tetra (Hyphessobrycon erythrostigma): Their peaceful nature and size make them compatible with firemouth cichlids, contributing to a vibrant community aquarium.


  • Tiger barbs (Puntigrus tetrazona): When kept in a sufficiently large school, their nippiness is minimized, allowing them to coexist with firemouth cichlids. Ensure the tank is spacious enough to accommodate their energy.
  • Cherry barbs (Puntius titteya): These smaller, peaceful barbs can do well with firemouths if the aquarium provides enough hiding spots.


  • Plecostomus (various species): Their bottom-dwelling habits and armored bodies keep them safe from being harassed by firemouth cichlids.
  • Corydoras catfish (Corydoras spp.): These peaceful bottom feeders are excellent for adding diversity to the tank’s bottom level without inciting the firemouth’s aggression.

Larger Livebearers

  • Swordtails (Xiphophorus hellerii): Their size and peaceful nature make them less likely targets for firemouth cichlids, adding color and activity to the aquarium.
  • Mollies (Poecilia spp.): Adaptable and generally peaceful, mollies can share a tank with firemouths if there’s enough space and hiding places.

Considerations for a Peaceful Community

  • Ensure the tank is large enough (55 gallons or more recommended) to provide ample space for territories and reduce aggression.
  • Include plenty of hiding spots (caves, plants, driftwood) to allow for retreat and stress reduction.
  • Consider the water conditions preferred by each species to ensure compatibility.
  • Monitor the tank closely after introducing new species to observe interactions and make adjustments if necessary.

Selecting tank mates for firemouth cichlids requires balancing the temperament, size, and environmental needs of potential companions. By considering these factors, you can create a diverse and engaging aquarium where all species thrive.

Firemouth Cichlid Tank Mates – The Best and the Worst - "Thorichthys meeki - Wilhelma 01" by H. Zell is licensed under CC BY-SA 3.0.
Firemouth Cichlid Tank Mates – The Best and the Worst – “Thorichthys meeki – Wilhelma 01” by H. Zell is licensed under CC BY-SA 3.0.

The Worst Firemouth Cichlid Tank Mates

Choosing inappropriate tank mates for firemouth cichlids can lead to stress, injury, or even death among aquarium inhabitants. Here are examples of what would be considered the firemouth cichlid tank mates, based on their temperament, size, and environmental needs:

Small, Timid Fish

  • Neon tetras: Their small size and timid nature make them easy targets for firemouth cichlids, especially during breeding times when firemouths become more aggressive.
  • Guppies (Poecilia reticulata): While colorful and active, guppies are too small and delicate to share a tank with territorial cichlids.

Slow-moving or Long-finned Fish

  • Fancy goldfish (Carassius auratus): Their slow swimming speed and delicate fins make them vulnerable to nipping and aggression from more active and territorial fish like firemouth cichlids. Also, they typically have other water requirements.
  • Betta fish (Betta splendens): Their long fins can attract unwanted attention from firemouth cichlids, leading to stress and injury.

Highly Aggressive or Large Predatory Fish

  • Oscar cichlids: Their large size and aggressive nature can lead to dominance over firemouth cichlids, potentially causing stress or harm.
  • African cichlids (various species from Lakes Malawi, Tanganyika, and Victoria): Their aggressive temperament and different water condition requirements often make them incompatible with firemouth cichlids.

Very Small or Fragile Invertebrates

  • Dwarf shrimp (e.g., Cherry shrimp, Caridina spp.): Their small size makes them potential prey for firemouth cichlids.
  • Delicate snails: Some smaller or more delicate snail species can be harassed or eaten by firemouth cichlids.

Considerations for Avoiding Poor Tank Mates

  • Aggression Levels: Avoid mixing firemouth cichlids with fish known for either extreme aggression, which can bully them, or with very passive fish that can become victims.
  • Size and Speed: Fish significantly smaller or slower than firemouth cichlids are likely to be stressed or injured.
  • Environmental Needs: Fish requiring vastly different water parameters (pH, temperature, hardness) from firemouth cichlids are poor choices due to the difficulty in meeting the needs of all aquarium inhabitants simultaneously.

Ensuring the well-being of firemouth cichlids and their tank mates involves careful consideration of the potential interactions between species. Avoiding these worst tank mates can help maintain a healthy, stress-free aquarium environment for your fish.


Choosing the right firemouth cichlid tank mates is crucial for creating a balanced and stress-free aquarium environment. While certain fish, such as larger tetras, certain barbs, compatible cichlids like angelfish and ram cichlids, and robust catfish species, can coexist peacefully with firemouth cichlids, others should be avoided to prevent stress, aggression, and potential harm. Small, timid fish, slow-moving species with long fins, highly aggressive or large predatory fish, and delicate invertebrates are among the worst choices for companions. By carefully selecting tank mates that match the firemouth cichlids in temperament, size, and environmental needs, aquarists can enjoy the dynamic interactions and beauty of a diverse aquatic community. Remember, the key to a successful community tank lies in understanding and catering to the specific needs of each inhabitant, ensuring they all thrive together in harmony.