Melanotaenia Maccullochi: a Dwarf Fish That Likes a Lot of Space

melanotaenia maccullochi space loving dwarf fish

The Dwarf Rainbowfish, scientifically known as Melanotaenia Maccullochi, is an intriguing species that demands our attention. This captivating fish, with its vibrant and iridescent coloring, has become a sought-after addition to aquariums worldwide.

However, it is not just their stunning appearance that makes them so fascinating. These fish have a unique preference for space, despite their diminutive size.

In this discussion, we will explore the intriguing behavior of Melanotaenia Maccullochi and discover why they thrive in setups that offer ample open space. Prepare to be amazed by the secrets of this extraordinary dwarf fish.

Key Takeaways

  • Melanotaenia Maccullochi is a small fish that grows up to 2.8 inches in size.
  • They have iridescent coloring that changes from blue and yellow to shiny silver, with bright red fins and black horizontal stripes.
  • Melanotaenia Maccullochi prefers to be kept in shoals of at least eight fish and thrives in heavily planted aquariums with open space.
  • They are compatible with other small, non-aggressive fish and have a diverse diet that includes high-quality dried foods, live foods, and frozen foods.

Description and Habitat

detailed species descriptions and environments

The Melanotaenia Maccullochi, a dwarf fish known for its iridescent coloring and striking red fins with black horizontal stripes, is native to Papua New Guinea and Australia. In the wild, these fish inhabit varied biotopes, from still ponds to flowing streams, with abundant vegetation in all habitats. Growing to a maximum of 2.8 inches, the Melanotaenia Maccullochi is a small but vibrant species.

When kept in captivity, their color develops gradually as they settle into the aquarium. To ensure their well-being, it is recommended to keep them in shoals of at least eight fish, in a heavily planted setup with lots of open space. Water conditions should have a pH of 5.5-7.5 and a temperature of 68-82°F. Proper care, including weekly partial water changes and clean water, is essential for their thriving in captivity.

Care Requirements

To ensure the thriving of the Melanotaenia Maccullochi in captivity, it is crucial to provide proper care and meet specific requirements. This includes maintaining optimal water parameters and creating an appropriate tank setup. The water parameters for Melanotaenia Maccullochi should have a pH level ranging from 5.5 to 7.5 and a temperature between 68-82°F. Regular partial water changes and clean water are essential for their well-being. In terms of tank setup, Melanotaenia Maccullochi prefer a heavily planted environment with ample open space for swimming. Providing hiding spots and a tight-fitting lid to prevent jumping is also important. To help the audience visualize these care requirements, an informative table can be presented:

Melanotaenia Maccullochi Water Parameters Melanotaenia Maccullochi Tank Setup
pH: 5.5-7.5 Heavily planted environment
Temperature: 68-82°F Ample open space for swimming
Regular partial water changes Hiding spots
Clean water Tight-fitting lid

Tank Mates

choosing compatible aquarium fish

When considering potential tank mates for Melanotaenia Maccullochi, it is important to choose small, non-aggressive species that can peacefully coexist in a community aquarium. These dwarf rainbowfish are compatible with other peaceful fish, but caution should be exercised when introducing them to aggressive species.

Melanotaenia Maccullochi has a narrow mouth, making it unable to swallow smaller tankmates. However, it is not safe to keep them with large Archerfish or larger Cichlids.

Additionally, water parameters play a vital role in the breeding of Melanotaenia Maccullochi. To successfully breed these fish, a separate breeding tank should be set up with appropriate plants or spawning mediums.

Maintaining a temperature of 80-84°F and a pH of 7.5 is crucial for the hatching and fertilization of the eggs.


Breeding Melanotaenia Maccullochi can be achieved successfully by creating a separate breeding tank with appropriate plants or spawning mediums, ensuring optimal water conditions, and providing high-protein foods before spawning. These breeding techniques are crucial for the successful reproduction of this dwarf fish.

The breeding tank should have a temperature of 80-84°F and a pH of 7.5. It is important to maintain these optimal breeding conditions to encourage the spawning process.

The male fertilizes the eggs, and the female lays batches of eggs daily. The eggs hatch in 7-10 days, and it is important to provide the fry with suitable food options.

Diet and Portion Control

healthy eating and moderation

The dietary needs and portion control of Melanotaenia Maccullochi are essential factors in maintaining their health and well-being. To ensure their nutritional requirements are met and to prevent overfeeding, it is important to follow proper diet and portion control practices.

Here are some key points to consider:

  • Importance of water conditions:
  • Maintaining a clean aquarium is crucial for the overall health of Melanotaenia Maccullochi.
  • Regular water changes help remove waste and maintain optimal water quality.
  • Maintaining a clean aquarium:
  • Excess food falling to the bottom of the tank can indicate overfeeding.
  • Overfeeding can lead to water parameter imbalances, impacting the health of the fish.
  • Portion control is important to avoid overfeeding and maintain a clean and balanced aquarium environment.

Size and Color Development

Size and color development in Melanotaenia Maccullochi is a gradual process that showcases the vibrant hues and distinct patterns of these dwarf rainbowfish. As these fish mature, they undergo significant changes in both size and coloration, making them a visually striking addition to any aquarium.

The size development of Melanotaenia Maccullochi is notable, as they can grow to a maximum length of 2.8 inches. However, it is important to note that the growth rate of these fish can vary depending on several factors, including diet, water quality, and tank conditions.

Additionally, the color maturation of Melanotaenia Maccullochi is a fascinating aspect to observe. Initially, the fish may exhibit duller colors, but as they settle into their environment and adapt to their surroundings, their iridescent hues become more pronounced. The blue and yellow hues gradually transform into shiny silver, complemented by bright red fins with black horizontal stripes.

This color development adds visual interest and beauty to the aquarium, captivating the attention of aquarists and enthusiasts alike.

Compatibility With Other Fish

fish compatibility and coexistence

When considering the compatibility of Melanotaenia Maccullochi with other fish species, it is important to take into account their peaceful nature and narrow mouths, which make them suitable tankmates for smaller, non-aggressive fish.

Here are some pros and cons of keeping Melanotaenia Maccullochi with larger fish:


  • Melanotaenia Maccullochi's peaceful nature makes them less likely to engage in aggressive behavior towards larger fish.
  • Their narrow mouths prevent them from preying on smaller tankmates, ensuring a harmonious coexistence.


  • Larger fish may see Melanotaenia Maccullochi as potential prey, leading to aggression and potential harm.
  • The presence of larger fish can create a stressful environment for Melanotaenia Maccullochi, affecting their overall well-being.

Here are some tips for introducing new tank mates to Melanotaenia Maccullochi:

  • Gradual acclimation: When introducing new fish, it is important to acclimate them slowly to the aquarium environment to minimize stress and potential aggression.
  • Monitor behavior: Keep a close eye on the interactions between Melanotaenia Maccullochi and the new tank mates. If signs of aggression or stress are observed, it may be necessary to separate the fish.
  • Provide hiding spots: Adding ample hiding spots, such as plants or caves, can help alleviate stress and provide refuge for Melanotaenia Maccullochi if needed.

Active Swimming Behavior

As we shift our focus to the active swimming behavior of Melanotaenia Maccullochi, it is important to understand how their energetic nature contributes to their overall well-being in the aquarium environment. These dwarf rainbowfish are known for their lively swimming patterns, constantly darting and exploring their surroundings. To ensure their optimal swimming experience, a well-designed tank setup is crucial. Providing them with ample open space allows them to freely navigate and showcase their natural behaviors. Additionally, incorporating plants and decorations that mimic their natural habitat will create a stimulating and enriching environment for these active swimmers. By carefully considering the swimming patterns and tank setup, aquarists can create an innovative and captivating aquarium that promotes the well-being of Melanotaenia Maccullochi.

Swimming Patterns Tank Setup
Lively Ample open space
Darting Stimulating décor
Exploratory Natural habitat

Diverse Diet Preference

wide range of food choices

The diet preference of Melanotaenia Maccullochi is characterized by a diverse range of food sources that contribute to their overall health and vitality. These fish have a varied diet, exhibiting both herbivorous and carnivorous feeding habits.

Their feeding behavior includes the following:

  • Herbivorous Feeding:
  • Melanotaenia Maccullochi consume plant matter such as algae and aquatic vegetation.
  • They graze on algae growth present on rocks, plants, and tank decorations.
  • Carnivorous Feeding:
  • These fish also actively prey on small invertebrates, including insects, worms, and small crustaceans.
  • They have a particular preference for live and frozen foods such as daphnia, mosquito larvae, brine shrimp, Mysis shrimp, and krill.

The diverse diet variety of Melanotaenia Maccullochi ensures that they receive the necessary nutrients for growth and vitality. Providing a balanced diet that encompasses both plant and animal-based foods is vital for their well-being.

Frequently Asked Questions

How Long Do Melanotaenia Maccullochi Live?

The lifespan of Melanotaenia Maccullochi, commonly known as the Dwarf Rainbowfish, can vary depending on various factors such as water quality, diet, and overall care. On average, they can live for 5-8 years with proper care and maintenance.

Can Melanotaenia Maccullochi Be Kept in a Small Tank?

Melanotaenia Maccullochi, a dwarf fish, requires a tank size that provides ample space for swimming. It is not suitable for small tanks as it thrives in heavily planted setups with lots of open space. Compatible tankmates should be small and non-aggressive.

Do Melanotaenia Maccullochi Require a Specific Type of Substrate in Their Tank?

Melanotaenia maccullochi does not require a specific type of substrate in their tank. They prefer heavily planted setups with open spaces. Breeding habits include egg scattering and separate breeding tanks with plants. They are compatible with other small, peaceful fish species.

Are Melanotaenia Maccullochi Jumpers?

Melanotaenia maccullochi, a dwarf fish, has the potential to jump out of the aquarium if not provided with a tight-fitting lid. Therefore, it is important to ensure the tank has appropriate measures in place to prevent any potential escapes.

Can Melanotaenia Maccullochi Be Kept With Shrimp or Snails in the Same Tank?

Melanotaenia Maccullochi can be kept with shrimp or snails in the same tank, as long as the shrimp and snails are small and non-aggressive. Tank decorations should provide hiding spots for the shrimp and snails to avoid predation.


In conclusion, Melanotaenia Maccullochi, the Dwarf Rainbowfish, is a captivating species that requires specific care to thrive in an aquarium setting.

With their vibrant colors and preference for shoals, these fish thrive in heavily planted setups with ample open space.

It is crucial to provide suitable tank mates and maintain appropriate water conditions for their well-being.

Additionally, their diverse diet preference and active swimming behavior contribute to their overall health and vitality.

An interesting statistic is that the Dwarf Rainbowfish can reach a maximum size of 2.8 inches, making them a small yet captivating addition to any aquarium.