Fish & Aquarium Signs

Funny novelty fish and aquarium metal signs for betta keepers, reef tank enthusiasts, and freshwater hobbyists, printed on heavy gauge rust-proof aluminum and made in the USA.

View more collections: Reptile & Exotic Pet Signs Cat Metal Signs Funny Dog Signs for Every Breed Farm Animal Signs Lake Monster Metal Signs Mothman & Winged Cryptid Signs Beast & Canid Metal Signs Bird Signs Wildlife Signs Aquatic & Marine Animal Signs Insect & Garden Metal Signs

Showing 1 - 24 of 48 products

a warning sign that says "WARNING" and "This property is protected by a highly trained Betta fish".

a warning sign that says "WARNING THIS PROPERTY IS PROTECTED BY A highly trained Betta fish. NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

Betta Fish Warning Metal Sign

From $14.95

6 reviews

a warning sign that states "This property is protected by a highly trained peacock. Not responsible for injury or possible death."

Plecostomus Warning Aquarium Sign

From $14.95

2 reviews

a warning sign that says "This property is protected by a highly trained Cichlid".

a warning sign that says "This property is protected by a highly trained Cichlid" and states that it is not responsible for injury or possible death.

Protected by Cichlid Warning Sign

From $14.95

1 review

a warning sign that says "This property is protected by a highly trained Anemone".

a warning sign that states "This property is protected by a highly trained anemone" and includes a graphic of a black and white anemone.

Anemone Warning Metal Tank Sign

From $14.95

a warning sign that says "WARNING" and "THIS PROPERTY IS PROTECTED BY A highly trained axolotl".

a warning sign that says "WARNING THIS PROPERTY IS PROTECTED BY A highly trained axolotl. NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

Axolotl Warning Tank Decor Sign

From $14.95

4 reviews

The image is a warning sign that states "This property is protected by a highly trained Archerfish. Not responsible for injury or possible death."

a warning sign that says "This property is protected by a highly trained Archerfish. Not responsible for injury or possible death."

Archerfish Tank Warning Sign

From $14.95

a warning sign that says "This property is protected by a highly trained GOURAMI not responsible for injury or possible death".

a warning sign that says "This property is protected by a highly trained GOURAMI" and states that it is not responsible for injury or possible death.

Gourami Warning Aquarium Sign

From $14.95

a warning sign that says "This property is protected by a highly trained leech".

Highly Trained Leech Yard Sign

From $14.95

The image is a warning sign that says "WARNING This property is protected by a highly trained Oscar Oscar not responsible for injury or possible death".

a warning sign that says "WARNING This property is protected by a highly trained Oscar Oscar not responsible for injury or possible death".

Oscar Fish Aquarium Metal Sign

From $14.95

8 reviews

a warning sign that says "WARNING" and "THIS PROPERTY IS PROTECTED BY A highly trained CLOWNFISH".

a warning sign that states "This property is protected by a highly trained clownfish", accompanied by a silhouette of a clownfish.

Clownfish Aquarium Metal Sign

From $14.95

2 reviews

a warning sign that says "WARNING: THIS PROPERTY IS PROTECTED BY A highly trained GOLDFISH. NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

a warning sign that states "This property is protected by a highly trained goldfish. Not responsible for injury or possible death."

Goldfish Warning Metal Sign

From $14.95

4 reviews

a warning sign that says "WARNING" and "ANGELFISH" in bold red letters. The sign also includes a black silhouette of an angelfish and a warning that it is protected by a highly trained Angelfish.

a warning sign that says "WARNING: THIS PROPERTY IS PROTECTED BY A highly trained ANGELFISH NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

Angelfish Warning Metal Sign

From $14.95

The image is a warning sign that states "This property is protected by a highly trained guppy" and warns that it is not responsible for injury or possible death.

a warning sign that says "This property is protected by a highly trained guppy" and "Not responsible for injury or possible death".

Guppy Fish Metal Warning Sign

From $14.95

7 reviews

The image is a warning sign that states that the property is protected by a highly trained fish, and it is not responsible for injury or possible death.

a warning sign that states "This property is protected by a highly trained fish", accompanied by a silhouette of a fish.

Highly Trained Fish Warning Sign

From $14.95

a warning sign that states "This property is protected by a highly trained Mantis Shrimp", indicating that the property is guarded by trained Mantis Shrimp.

a warning sign that states "This property is protected by a highly trained MANTIS SHRIMP", indicating that the property is guarded by a highly trained manta ray.

Mantis Shrimp Aquarium Metal Sign

From $14.95

a warning sign that says "WARNING THIS PROPERTY IS PROTECTED BY A highly trained MYSTERY SNail".

Mystery Snail Security Metal Sign

From $14.95

a warning sign that says "This property is protected by a highly trained PIRANHA" and is responsible for injury or possible death.

The image is a warning sign that states "This property is protected by a highly trained Piranha. Not responsible for injury or possible death."

Piranha Aquarium Metal Guard Sign

From $14.95

The image is a warning sign that states "This property is protected by a highly trained Nerite snail", indicating that the property is guarded by a trained Nerite snail.

a warning sign that says "This property is protected by a highly trained Nerite snail" and states that it is responsible for injury or possible death.

Nerite Snail Aquarium Metal Sign

From $14.95

a warning sign that says "WARNING THIS PROPERTY IS PROTECTED BY A HIGHLY TRAINED SEA URCHIN NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

a warning sign that says "This property is protected by a highly trained sea urchin" and is responsible for injury or possible death.

Sea Urchin Warning Sign

From $14.95

The image is a warning sign that states "This property is protected by a highly trained Damselfish. Not responsible for injury or possible death."

a warning sign that says "This property is protected by a highly trained Damselfish. Not responsible for injury or possible death."

Damselfish Warning Metal Sign

From $14.95

a warning sign that states "This property is protected by a highly trained Bamboo Shrimp", indicating that the property is guarded by a trained bamboo shrimp.

The image is a warning sign that states "This property is protected by a highly trained Bamboo Shrimp", indicating that the property is guarded by a trained bamboo shrimp.

Bamboo Shrimp Aquarium Guard Sign

From $14.95

a warning sign that states "This property is protected by a highly trained sea anemone. Not responsible for injury or possible death."

a warning sign that says "WARNING THIS PROPERTY IS PROTECTED BY A HIGHLY TRAINED SEA ANEMONE NOT RESPONSIBLE FOR INJURY OR POSSIBLE DEATH".

Sea Anemone Aquarium Metal Sign

From $14.95

a warning sign that says "This property is protected by a highly trained Otocinclus catfish", indicating that the property is protected by a highly trained otocinclus catfish.

Otocinclus Catfish Warning Sign

From $14.95

The image is a warning sign that states "This property is protected by a highly trained GOBY" and warns that it is not responsible for injury or possible death.

a warning sign that says "This property is protected by a highly trained Goby" and is responsible for injury or possible death.

Goby Fish Aquarium Metal Sign

From $14.95

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For the people whose living room centerpiece is a tank, whose vacations are quietly planned around water changes, and who can identify every fin on a betta at a glance. This collection is for the freshwater crowd, the reef tank crowd, and the weird-fish-people crowd we love most.

Every sign here is a novelty humor sign, not an actual warning or safety notice. They simply look official enough to post above the tank, the filter, or the door of the fish room that guests enter only with proper supervision and advance notice.

All fish and aquarium signs are made in the USA and exclusive to Designs by Linda Nee. Each one is printed directly onto heavy gauge rust-proof aluminum using UV resistant ink, with no decals and no vinyl. Species covered include betta fish, goldfish, clownfish, angelfish, cichlid, oscar, plecostomus, axolotl, archerfish, gourami, anemone, and more from both freshwater and reef tanks.

Signs come with pre-drilled mounting holes and are ready to hang straight out of the package. Above the aquarium, on the fish room door, in the home office where the tank lives, or gifted to the aquarist in your life who has strong opinions about water hardness and even stronger opinions about their fish.

Strong starting points include the Betta Fish Warning Metal Sign, the Clownfish Aquarium Metal Sign, the Axolotl Warning Tank Decor Sign, the Goldfish Warning Metal Sign, and the Plecostomus Warning Aquarium Sign.

For more, browse the full Animal Signs collection, explore Reptile and Exotic Pet Signs for the tank-adjacent crowd, check out Aquatic and Marine Signs for ocean species, or visit Most Loved to see what fellow fish people keep choosing.

Frequently Asked Questions

Are these real warning signs or novelty aquarium signs?
Every sign in this collection is a novelty humor sign, not an actual safety or regulatory warning. They are designed to look amusingly official while celebrating the specific fish or aquatic creature that anchors your tank. No liability is implied, though your cichlid may feel otherwise.

What are the signs made from?
Each sign is printed directly onto heavy gauge rust-proof aluminum using UV resistant ink. There are no decals, no vinyl overlays, and nothing that peels. The design bonds to the metal itself for a finish that holds up indoors and in humid tank-adjacent environments.

Do the signs come ready to hang?
Yes. Every sign arrives with pre-drilled mounting holes so you can hang it immediately without additional hardware. They work above tanks, on walls, on doors, and anywhere else your fish have established territorial claims.

Which fish and aquarium species do you have signs for?
This collection includes betta fish, goldfish, clownfish, angelfish, cichlid, oscar, plecostomus, axolotl, archerfish, gourami, anemone, and more across freshwater and reef species. All designs are exclusive to Designs by Linda Nee and made in the USA. Do not see your fish? Reach out. We probably have it.