Lawnmower Blenny: The Small But Mighty Fish You Need in Your Tank

lawnmower blenny

The distinct look of lawnmower blenny has made them a popular choice among aquarium enthusiasts thanks to their effectiveness in managing algae growth.

Our discussion on the various aspects of looking after these marine fish will delve into their size, potential threats they may face in captivity, and tank mate compatibility criteria that should be met before introducing them into an enclosed environment with other fish species and coral reefs.

Additionally, understanding their proclivity towards aggression as well as how well they get along with clownfish can only help enhance your ability to nurture your pets while unlocking maximum growth potential.


Lawnmower Blenny Size

Lawnmower blenny (Salarias spp.) typically grow to an average size of 4 to 5 inches (10 to 13 cm) in length, making them a relatively small addition to your aquarium. While individual growth rates may vary, it’s important to consider their potential size when planning their housing and tank mates.

Lawnmower Blenny Dangerous

Although lawnmower blennies pose no significant threat of danger to humans, cautious handling is necessary because of their powerful jaws and razor-sharp teeth. Any aggressive interactions should be avoided entirely since that could result in injuries for both parties involved. To prevent harm from occurring, it is best to avoid stressing the fish out unnecessarily.

Lawnmower Blenny Tank Mates

Lawnmower blennies are generally compatible with a variety of peaceful and non-aggressive fish species. When choosing tank mates, consider their size, temperament, and habitat requirements. Here are some suitable options:

  1. Gobies: Many goby species, such as the watchman gobies or neon gobies, make excellent companions for lawnmower blenny. They share similar peaceful behavior and bottom-dwelling habits.
  2. Damselfish: Certain species of damselfish, like the Azure damselfish or Talbot’s damselfish, can coexist with lawnmower blennies, especially in larger tanks with ample hiding spots.
  3. Clownfish: Lawnmower blenny can peacefully cohabitate with clownfish, creating an intriguing dynamic in the aquarium. Ensure the tank provides sufficient space and hiding spots for both species.
  4. Small Tangs: Some small tangs, like the yellow tang or Kole tang, can be compatible with lawnmower blennies in larger aquariums. However, closely monitor their behavior and provide ample space to reduce any potential aggression.
  5. Blennies and Dragonets: Other blenny species, such as the bicolor blenny or the midas blenny, can make suitable tank mates for the lawnmower blenny. Dragonets like the mandarin fish can also coexist peacefully.

Lawnmower Blenny Reef Safe


Reef-keeping enthusiasts may appreciate the lawnmower blenny for its reef-safe attribute. In well-established reef tanks, these creatures are unlikely to harm corals or any other invertebrates residing within them. Additionally, their powerful grazing capability assists with controlling algae growth and promoting overall cleanliness.

However, it’s important to note that some lawnmower blennies may develop a taste for certain soft corals or sessile invertebrates. Monitor their behavior closely and ensure an ample food source is available to discourage any potential grazing on corals. It’s always recommended to research the specific needs and compatibility of your chosen corals before introducing a lawnmower blenny to a reef tank.

Lawnmower Blenny Tank Size

To provide a comfortable and stimulating environment for lawnmower blenny, it’s essential to consider the appropriate tank size. A minimum tank size of 30 gallons (113 liters) is generally recommended for a single lawnmower blenny. However, larger tanks are preferred, especially if you plan to keep them with other fish or invertebrates.

A larger tank not only provides more swimming space but also allows for the establishment of diverse microhabitats, including ample hiding spots, caves, and rock structures. These features mimic their natural environment and contribute to their overall well-being.

Lawnmower Blenny Temperature

The key element for promoting the vitality and longevity of lawnmower blenny lies in maintaining a consistent water temperature within their recommended range. Hailing originally from tropical marine habitats, these fish exhibit optimal health when exposed to a temperature spectrum of roughly 74°F – 80°F (23°C – 27°C).

Use a reliable aquarium thermometer to monitor the water temperature consistently. It’s recommended to invest in a heater with a built-in thermostat to maintain the desired temperature range. Sudden fluctuations or prolonged exposure to temperatures outside their preferred range can stress lawnmower blenny and compromise their immune system.

Are Lawnmower Blenny Aggressive?

Lawnmower blennies are generally peaceful and non-aggressive fish. They exhibit a calm temperament and rarely engage in aggressive behaviors toward other tank inhabitants. However, like any fish, individual personalities can vary, and there may be exceptions to this general rule.

In some cases, lawnmower blenny may display territorial behavior, especially if they feel threatened or if their personal space is invaded. This is more likely to occur if they are kept in a confined space with limited hiding spots or if they are introduced to aggressive or territorial tank mates.

To mitigate any potential aggression, provide ample hiding places and create a well-structured aquarium environment. This allows lawnmower blenny to establish their territories and reduces the likelihood of conflicts with other fish. Additionally, carefully select tank mates known for their peaceful nature to promote a harmonious community.

Regular observation and monitoring of the fish’s behavior will help identify any signs of aggression early on. If necessary, be prepared to provide alternative housing arrangements for aggressive individuals to maintain a peaceful tank environment.

Can Lawnmower Blenny Live with Clownfish?

Lawnmower blenny can coexist harmoniously with clownfish under the right conditions. Both species have different behavioral traits and occupy different areas of the tank, which reduces the likelihood of direct competition or aggression.

When introducing lawnmower blenny and clownfish, consider the following:

  1. Tank Size: Provide a spacious tank with ample hiding spots and territories for both species. A larger tank minimizes territorial disputes and provides sufficient swimming space.
  2. Compatibility: Choose clownfish species known for their peaceful nature, such as the Ocellaris clownfish or the Percula clownfish. Avoid aggressive or dominant clownfish species that may pose a threat to the lawnmower blenny.
  3. Introduction Process: Introduce the lawnmower blenny and clownfish simultaneously or introduce the lawnmower blenny first to establish its territory. This helps reduce potential aggression during the introduction process.


Lawnmower blennies are captivating aquarium fish known for their unique appearance and algae-eating capabilities. By understanding their size, tank mate compatibility, reef safety, tank size requirements, temperature preferences, aggression tendencies, and growth potential, you can create an ideal environment for these fascinating creatures.

Providing a suitable tank size, maintaining optimal water conditions, and selecting compatible tank mates are crucial for the well-being of lawnmower blennies. Their peaceful nature and reef-safe behavior make them an excellent addition to a community or reef aquarium.

Remember to monitor their growth, behavior, and overall health regularly. If any issues arise, seek advice from knowledgeable professionals to ensure the best care for your lawnmower blennies.


  1. Is lawnmower Blenny suitable for beginners?
    • Yes, lawnmower blennies are generally considered suitable for beginners due to their ease of care and peaceful nature. However, proper research and understanding of their specific needs are still important.
  2. Does a lawnmower blenny require a specialized diet?
    • While lawnmower blennies are primarily herbivores, they benefit from a varied diet that includes algae, seaweed, and high-quality marine-based foods. Supplementing their diet with occasional live or frozen foods can also be beneficial.
  3. Can a lawnmower blenny jump out of the tank?
    • Yes, lawnmower blennies have been known to jump out of open aquariums, especially if they feel stressed or threatened. It’s recommended to have a securely fitted lid or mesh cover to prevent accidental escapes.
  4. Are lawnmower blennies suitable for reef aquariums?
    • Yes, lawnmower blennies are generally considered reef safe. However, some individuals may nip at certain soft corals or sessile invertebrates. Monitor their behavior and provide ample food sources to minimize any potential grazing.
  5. How can I prevent lawnmower Blenny from damaging corals?
    • To prevent lawnmower blenny from damaging corals, ensure they have a well-balanced diet that includes enough algae and other suitable foods. Offering algae-based supplements or target feeding can help redirect their grazing behavior away from corals.

Recommended Reading: Why Every Aquarium Needs Water Sprite Plant

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