Glowing Fish: What Are GloFish?

Updated Jun. 13, 2024
Glofish in tank

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What Are GloFish?

What Are GloFish?

GloFish® are an exciting new type of fish that are becoming more popular because of their vibrant colors. These glowing fish are attractive display animals for any tropical community fish tank.

GloFish get their name from their fluorescent coloration. They come in a variety of fluorescent colors such as red, pink, orange, green, blue, and purple. These colors a called Starfire Red, Electric Green, Sunburst Orange, Cosmic Blue, Galactic Purple, and Moonrise Pink.

GloFish species actually come from a number of different fish species. All these colors can be found in the following species of fish:

  • Zebra fish (Danio rerio)

  • Tetra (Gymnocorymbus ternetzi)

  • Tiger barbs (Puntius tetrazona)

  • Rainbow shark (Epalzeorhynchos frenatum)

  • Betta (Betta splendens)

How Are GloFish Made?

GloFish are one of the first genetically modified animals to become popular within the pet trade. These fish were developed by introducing different fluorescent proteins into the genome of the fish at the early stages of development. Unlike other colorful varieties of pet fish that are injected with dye, these fish will pass on their glowing colors to their offspring.

The goal of producing fish that have these fluorescent proteins was to improve biomedical and environmental research. It was thought they would be able to detect pollution within the environment. When these transgenic fish were added to contaminated water source, researchers were able to note changes in the fishes’ coloration. Now, these fish are bred specifically for the ornamental fish pet trade.

GloFish come in a variety of fluorescent colors such as red, pink, orange, green, blue, and purple.

GloFish absorb light in a specific wavelength then re-emit light, giving them their glowing appearance. Their color can be enhanced by blue LED, actinic, and black lights.

The genes that are responsible for the color of GloFish have been placed within the genetic code of each fish, so they are passed on from generation to generation. These genes produce proteins that fluoresce which give GloFish their glow!

GloFish are not available in all places due to legal issues surrounding their genetically modified state. Determine if GloFish are legal in your state before you add them to your tank.  

GloFish Tank Mates

As with all fish, selecting fish species to live with your GloFish is important to maintain harmony within your fish tank.

Community species of GloFish can be safely housed together with other community fish species. These fish may include:

Are GloFish Aggressive?

GloFish varieties are no more aggressive than their normally colored counterparts. This is not due to their glowing nature, but just their species.

In the wild, GloFish would be more vulnerable to predation compared to the wild forms of each species given their vivid coloration. However, this is not a concern in captive aquariums. No matter the color, species aggression is important to understand when selecting additional fish for a fish tank. Do not include any aggressive fish species within your tank as they might try to eat your easy-going GloFish. 

GloFish Tank Setup

Habitat size should be based on:

  • The adult size of the species you keep

  • The amount of fish you keep within the aquarium

GloFish can be successfully housed in tanks from 5 gallons for small Zebra GloFish to aquariums greater than 20 gallons for multiple GloFish species.

GloFish Water Quality

As with any other fish species, water quality is extremely important in maintaining a thriving GloFish tank.

It’s important to use GloFish water conditioner for your fish tank. This neutralizes any impurities or chlorine in the water that can be harmful to the fish.

Proper filtration is also necessary to maintain optimal water quality to ensure health. Water circulation should be provided for water currents and ensure high oxygen levels in the water, as GloFish are found in habitats with high water oxygen levels.

Regularly test the water quality of your tank. Stable values of pH, ammonia, nitrate, nitrite, and water temperature are vital to the health of any aquatic habitat. Home water quality test kits can be purchased online.

Water quality should be maintained in the standard ranges for freshwater tanks.

Do GloFish Need a Heater?

Yes, an aquarium heater is important to ensure stable water temperatures. An appropriate water temperature for most GloFish species is 72–82 degrees F.

GloFish Aquarium Decor

GloFish can benefit from having enrichment within their habitats. Decor can be used to provide structure and hides within the environment.

Structures that provide shelter include plants, rock caves, and hollow logs. Additional environmental decor, marketed under the GloFish brand, can add fluorescent color to the rest of the habitat, including items such as substrates and plants, when placed under blue LED lighting.

What To Feed GloFish

GloFish can be fed a balanced diet of flakes, pellets, and frozen or freeze-dried food items, including:

  • Brine shrimp

  • Mysis shrimp

  • Bloodworms

How Often To Feed GloFish

Offer small amounts of food to your fish once or twice a day. Only offer enough food that your fish can eat within 1–2 minutes of feeding. Thaw any frozen food items immediately before feeding.

GloFish can make fantastic pets for kids and adults alike. If you are looking to have a pet fish with vibrant colors, GloFish are a great option for a new freshwater tank.

With many GloFish species options available, these beautiful fish can be housed in many tank sizes in a variety of different homes. These fish can provide hours of entertainment for your entire family.

GloFish FAQs

How big do GloFish get?

GloFish size will depend on the specific species of fish you adopt. Most GloFish will generally grow to 1.5–6 inches in length.

Are GloFish natural?

No, you would not find GloFish naturally in the wild, but other than their color, there are no differences between these fish and their typical colorations. Without human intervention, this variety of fish would not have occurred on its own.

How long do GloFish live?

GloFish can live anywhere between 3–8 years under appropriate conditions.

References

Amanuma K, Takeda H, Amanuma H, Aoki Y. Transgenic zebrafish for detecting mutations caused by compounds in aquatic environments. Nat Biotechnol. 2000;18(1):62-65.

References


Sean Perry, DVM

WRITTEN BY

Sean Perry, DVM

Veterinarian

Dr. Sean Perry completed his undergraduate degree at the University of California, Santa Cruz, earning a Bachelor of Science in...


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