Lifespan. The Lawnmower Blenny fish can live up to 2-4 years, but some specimens have even lived longer in well cared for aquariums.

Are blennies Hardy?

Most blennies are hardy fish and have a tendency to be long-time residents once they have become acclimated to your tank. All blennies should have hiding places in various nooks and crannies in your aquarium, which can be created by adding rocks or shifting your artificial landscape to accommodate them.

Do blennies sleep?

Yes they do sleep..