Lawnmower Blenny

Lawnmower Blenny key facts

Care level

Beginner-friendly

Lifespan

4-6 years

Size

10-13cm

Temperature

24〜26℃

Diet

Algae, Pellets

Notes

Starves without algae, train to eat pellets

Water Temperature & Quality

Keep the water at 24–26°C and specific gravity around 1.023–1.025. Adults reach 10–13cm and do best where filamentous algae grows on rock.

Tank Mates & Compatibility

It fights with its own kind and similarly shaped blennies, so keep one per tank. Few problems with other fish.

Diet & Feeding

A herbivore that scrapes filamentous algae off rock with comb-like teeth. Do not treat it purely as a cleaner; supplement with nori sheets and plant-based pellets.

Housing

It rests on rocks with its fins raised. Arrange live rock to provide both algae-covered surfaces and resting spots.

About Lawnmower Blenny

The Lawnmower Blenny is a beginner-friendly marine fish that grazes on algae. It lives 4 to 6 years and grows to 10-13 cm, prized for its comical expressions and algae-eating habits.

7 things to know before welcoming a Lawnmower Blenny

1. 1Feed Prepared Food When Algae Runs Low

   Since this fish relies mainly on algae, it can become malnourished once the tank's algae supply is depleted. Once algae becomes scarce, supplement its diet with seaweed sheets or prepared foods to keep its nutrition stable.

2. 2Rests on Rockwork

   It is often seen resting on rocks with its fins raised. Arranging live rock to provide algae-covered surfaces and resting spots will help it feel settled.

3. 3Provide Rockwork for Hiding

   This fish likes to tuck itself into crevices among the rocks. Arranging live rock to create several hiding spots will reduce stress and encourage more natural behavior.

4. 4Territorial Toward Its Own Kind

   While peaceful toward other fish, it tends to fight with its own species and with similarly shaped blennies. Keeping one per tank is the basic rule, so avoid combining it with other blennies.

5. 5A Lid Is Essential

   When startled, it can leap quite forcefully, and an inadequately covered tank risks it jumping out. Be sure to fit a secure lid or cover glass and close off any gaps.

6. 6Generally Peaceful With Other Fish

   As blennies go, it is relatively peaceful and generally suits community tanks with other small marine fish. However, due to its territorial streak, keep an eye on compatibility when pairing it with similarly shaped or behaving species.

7. 7Best Introduced After Algae Has Established

   Introducing it into a newly set up tank with little algae growth can leave it with too little to eat. Consider waiting until algae has developed somewhat, or plan to train it onto prepared foods from the start.

Frequently asked questions about Lawnmower Blenny

Q.What should I do once it has eaten all the algae in my tank?

A.Once algae becomes scarce, offer seaweed sheets or prepared foods to make up for it. Most individuals adapt well and will readily eat prepared foods.

Q.Can it be kept together with other marine fish?

A.It is generally peaceful and can be kept with other small marine fish without issue. However, it may become territorial and aggressive toward its own species or similarly shaped blennies.

Q.Does it ever jump out of the tank?

A.It has a tendency to leap when startled, so in an uncovered tank it may jump out. Fitting a secure lid or cover glass with no gaps helps prevent this.

Q.Is it safe to keep in a reef tank with corals?

A.As an algae grazer, it generally does not target corals directly, so it is commonly kept in reef tanks. It also does well in setups with plenty of live rock.

Q.How difficult is it to keep?

A.It is considered beginner-friendly, being hardy and adaptable to water conditions. That said, feeding still requires some attention, such as ensuring algae supply and transitioning to prepared foods when needed.

Useful tools for Lawnmower Blenny care

Learn more about Lawnmower Blenny in the encyclopedia

More in this category