Not furry, but we like them anyway.

Lawnmower Blenny

Salarias fasciatus

Also called Jewelled blenny, Banded blenny, Blennius fasciatus (original name)

SpeciesShort profile

From Indo-Pacific: Red Sea and East Africa to Samoa, north to the Ryukyu Islands and south to the Great Barrier Reef and New Caledonia1 2

At a glance the quick version

Length10 to 14 cm1 2 3

Sizesmall

Grazes algae from rocks all day

Full of personality and expression

Good at changing colour to blend in

3 2

Looks how to spot one

Elongated blenny

A long-bodied blenny in olive to brown, marked with dark bars and many pale spots of different sizes. Dark lines run along the front of the body and small blue spots dot the rear, giving a mottled camouflage look.2 1 3

Coloursolivebrowndark barswhite spotsblue spots2 1

Personality what they are like

Peaceful with most fish, though it may defend its patch against other blennies, gobies or dartfish in a small tank.3

Daily activity how busy a day looks

Moves from rock to rock grazing and perching; it is a good jumper.3 1

Grooming and care the hands-on bits

Best added to a mature tank with plenty of live rock to graze. Keep a secure lid on the aquarium.3

Home where they are happiest

Minimum about 30 US gallons (114 L) with plenty of live rock. In the wild it lives on very shallow reef flats, lagoons and weedy rocky areas from the surface down to about 8 m.3 1 2

Food basics what goes in the bowl

Grazes surfaces in the wild, and studies find detritus makes up much of what it eats. In the aquarium, offer marine algae, seaweed, spirulina and algae-based foods 2 to 3 times a day.1 2 3

Company who they like around

Adults are usually solitary; keep one per tank.1

The story where it all began

Marcus Elieser Bloch described it in 1786 as Blennius fasciatus. Georges Cuvier later made it the type species of his new genus Salarias. It is now one of the best-known algae grazers in the marine hobby.2

Fun facts for the dinner table

1
It can breathe air for short periods, which helps it live in shallow tide pools.1
2
Despite its nickname, plant matter is only a small part of its natural diet.2
3
It changes colour to blend in with its surroundings.2
4
It is sometimes called a rock skipper because of how well it jumps.3

Recognised by the official bits

IUCN Red List: Least Concern (assessed 2009)1

The care rhythm a typical week and year

A typical home-care rhythm for a Lawnmower Blenny. A starting point, not a vet's advice.

FeedingSmall amounts once or twice a dayevery day
Temperature checkevery day
Salinity checkevery week
Top-upTop up evaporation with fresh RO water, not salt waterevery day
Water testevery week
Water changeAbout 10 to 20% of the waterevery 2 weeks
Glass cleanevery week

Owner questions the things everyone asks

How often should I feed my Lawnmower Blenny?

Feed your Lawnmower Blenny 2 to 3 times a day with marine algae, seaweed, spirulina, and algae-based foods. Furry Diary's starting plan suggests small amounts once or twice daily, but adjust based on how much algae it grazes from the tank.1 2 3 Pet Wiki plan

What does a Lawnmower Blenny eat, and what should it never eat?

It eats marine algae, seaweed, spirulina, and algae-based foods, and in the wild it grazes on detritus. Never feed it meaty foods or anything not algae-based, as its digestive system is built for plant matter.1 2 3

How much space does a Lawnmower Blenny need?

A minimum of about 30 US gallons (114 liters) with plenty of live rock is recommended. This gives it room to graze and perch, and helps it feel secure.3 1 2

What temperature, light or water does a Lawnmower Blenny need?

It needs typical tropical marine conditions, but specific numbers vary. Ask your local fish store or an exotic-pet vet for exact temperature, salinity, and lighting based on your tank setup.

How often should I clean a Lawnmower Blenny's home?

Furry Diary's plan suggests a weekly glass clean and a 10 to 20% water change every two weeks. Also test water weekly and top up evaporation daily with fresh RO water. Pet Wiki plan

Can a Lawnmower Blenny live with others?

Yes, it is peaceful with most fish, but keep only one per tank as adults are usually solitary. It may defend its patch against other blennies, gobies, or dartfish in a small tank.3 1

How long does a Lawnmower Blenny live?

Lifespan varies with care, but with a good diet and stable tank conditions, it can live several years. For a more precise estimate, ask a reputable breeder or an exotic-pet vet.

Can I handle a Lawnmower Blenny?

It is best not to handle it, as it is a good jumper and stress can harm it. Always use a secure lid and move it with a container if needed.3 1

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

Bicolor Blenny

Tailspot Blenny

Midas Blenny

Where this comes from

Every fact on this page has a numbered source. Spotted an error? [email protected].

FishBase: Salarias fasciatus fishbase.seused for distribution, size, depth, habitat, diet, air breathing, IUCN
Wikipedia: Salarias fasciatus en.wikipedia.orgused for appearance, diet detail, colour change, history
Saltwaterfish.com: Lawnmower Blenny saltwaterfish.comused for care, tank size, diet, temperament

Checked 2026-09-30. Text is written in our own words from these sources.