Lawnmower Blenny

Salarias fasciatus

Last updated: May 27, 2024
Verified by: AZ Animals Staff
Roberto Dani/

Must be in temperatures of 78 degrees Fahrenheit to breed


Lawnmower Blenny Scientific Classification

Scientific Name
Salarias fasciatus

Read our Complete Guide to Classification of Animals.

Lawnmower Blenny Conservation Status

Lawnmower Blenny Locations

Lawnmower Blenny Locations

Lawnmower Blenny Facts

Group Behavior
  • Mainly solitary
Fun Fact
Must be in temperatures of 78 degrees Fahrenheit to breed
Estimated Population Size
Biggest Threat
Bigger fish
Most Distinctive Feature
Color-changing body, smooth lips, tentacle-like extremities, fat belly.
Other Name(s)
Jeweled Rockskipper, algae blenny, banded blenny, banded-jeweled blenny, barred blenny, lineated blenny, lined blenny, painted blenny, sailfin blenny.
Gestation Period
Optimum pH Level
8 – 8.4
Rocky substrate
Any larger fish
Favorite Food
Common Name
Jeweled Blenny

Lawnmower Blenny Physical Characteristics

  • Brown
  • Red
  • Blue
  • White
  • Tan
  • Orange
Skin Type
2-5 years
14 cm

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The Lawnmower Blenny (also known as the Jeweled Rockskipper, algae blenny, or banded blenny) is a saltwater fish, primarily found in Australasia.

It is not sought after as a commercial fish for food, but it is a popular addition to many fish tanks because of the changing color of its body.

5 Lawnmower Blenny Facts

1. The color of the Lawnmowner Blenny changes with its environment and mood.
2. It exclusively lives in shallow saltwater, consuming algae on the surface of rocks.
3. They only breed in the late spring and early summer months, due to the change in warmth.

Lawnmower Blenny Classification and Scientific Name

Originally discovered in 1786, the lawnmower blenny’s scientific name is Salarias fasciatus. While “Salarias” comes from the Latin word for trout, “fasciatus” means “banded.” They have many common names they go by, including the Jeweled Rockskipper, algae blenny, banded blenny, banded-jeweled blenny, barred blenny, lineated blenny, lined blenny, painted blenny, and sailfin blenny.
The lawnmower blenny is in the order Blenniiformes, which includes 151 genera and almost 900 different species. The order includes many types of fish, though only six families are actually classified as “true” blennies. The family is Blenniidae.

Lawnmower Blenny Appearance

Part of the reason that the Lawnmower Blenny finds itself on the minds of pet owners is due to the changing color of its body. At no more than 3.7 to 4.2 inches in length, the color of the entire body can change to blend in with its surroundings, protecting it from predators. The intensity of these changing colors changes with their mood as well. To break up the color, it also features white spots along the body and darker lines towards the front. While the rest of the body can change, there are consistently blue spots that outline the back of their body.
With no notch in the dorsal fin, these fish have smooth lips with tentacle-like cirri along their body. They have a rather fat belly, making them look almost comedic.

Lawnmower Blenny Distribution, Population, and Habitat

Where to Find Lawnmower Blennies and How to Catch Them

The easiest place to find the saltwater blenny in nature is in Australasia, ranging from East Africa to the Islands of Micronesia. It prefers to live along shallow reef flats, allowing them to consistently graze on the algae on them. Their preferred water type is saltwater.

Though their actual population is unknown, they are considered Not Extinct, and no conservation efforts are being made currently. Since they are often kept as pets, they don’t need to be sourced from the wild to care for. Instead, breeders will sell them directly to pet stores. If you need to catch one of these fish in the tank to clean, using a net is the most you’ll need.

According to the IUCN Redlist of endangered species, the lawnmower blenny is considered least concern.

Lawnmower Blenny Predators and Prey

Unfortunately for the Lawnmower Blenny, this fish is primarily prey for other animals. Though they are technically considered to be an herbivore, they are more accurately referred to as detritivores, which means their diet consists of dead organic material. Their main food is algae.

What eats Lawnmower Blennies?

The Lawnmower Blenny is often consumed by fish larger than it is, like bluefish, weakfish, and striped bass. To protect itself from predators, it uses the changing color of its body to hide. It sometimes hides in oyster reefs, but it is a natural part of the bottom of the food chain.

What does the Lawnmower Blenny eat?

While Lawnmower Blenny doesn’t really have any prey that it goes after, it can become aggressive with other fish in its tank as it gets older. This aggression isn’t really noted in the wild because it has plenty of space to roam.

Lawnmower Blenny Reproduction and Lifespan

Typically, the Lawnmower Blenny spawns in the late spring and early summer between April and June. The mating is set off by the increased temperature, which pet owners can replicate in their tank with enough dedication. If this environment is changed, it is possible to breed them at home with highly specific care, but it can be difficult for a novice. The tank must be raised to 78 degrees Fahrenheit and breeding often has to be moved to another tank.
In the wild, however, they lay eggs in empty shells, allowing males to fertilize them. Once on the substrate of these shells, they will stay there until they hatch. The resulting young – larvae – will stay in shallow water and feed on plankton.
According to researchers, there’s no particular age that the Lawnmower Blenny has to reach for sexual maturity. It doesn’t matter whether another female or male is around them. However, it takes

Lawnmower Blenny In Fishing And Cooking

The Lawnmower Blenny is a rather small fish, so it is not ordinarily fished as a delicacy. There’s no commercial demand for these fish to eat, but the pet trade is popular for him.

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About the Author

Growing up in rural New England on a small scale farm gave me a lifelong passion for animals. I love learning about new wild animal species, habitats, animal evolutions, dogs, cats, and more. I've always been surrounded by pets and believe the best dog and best cat products are important to keeping our animals happy and healthy. It's my mission to help you learn more about wild animals, and how to care for your pets better with carefully reviewed products.

Lawnmower Blenny FAQs (Frequently Asked Questions) 

What is a lawnmower blenny?

It is a saltwater fish with a fat belly, smooth lips, and a body that changes color. They primarily eat algae, and they require a tank size of no less than 40 gallons. If their tank size isn’t big enough for hiding places, they may become aggressive with other fish in it. For the most part, they are peaceful.

What will a Lawnmower Blenny eat?

These fish are at the bottom of the food chain. Their diet primarily consists of different types of algae. In fact, they get the nickname “lawnmower blenny” from the way that they graze from rock to rock to clear through all the algae they eat.

Is the Lawnmower Blenny aggressive?

The Lawnmower Blenny is not a predator, so it is not aggressive towards humans. While they tend to maintain a peaceful attitude towards the other fish in their tank, aging can make them a little less willing to cooperate. It may be best to increase their tank size at this time.

Are lawnmower blennies Hardy?

Yes. Though it is important to care for them properly, they won’t react to small changes if something happens in their tank. They even heal quickly from disease if they get sick.

Will a Lawnmower Blenny eat hair algae?

Hair algae are the main reason that pet owners buy the Lawnmower Blenny. It helps to control hair algae in the tank, which keeps the other fish alive and healthy.

Where is the Lawnmower Blenny found?

The main location of the Lawnmower Blenny is Australasia. It prefers to live on rocky areas with plenty of algae to eat.

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