Introduction

The GloFish® (Danio rerio) is a popular tropical freshwater aquarium fish. It belongs to the Cyprinidae family under Order Cypriniformes of Class Actinopterygii. It is also known as zebrafish that is native to the streams of the southeastern Himalayan region. It is distributed in parts of India, Pakistan, Bangladesh, Nepal and Burma. This species inhabits streams, canals, ditches, ponds and slow-moving or stagnant water bodies including rice fields. The GloFish® is an important vertebrate model organism in scientific research due to its notable regenerative abilities. At present it is modified by researchers to produce several transgenic danio.

GloFish®’s Overview

The GloFish® has fusiform and laterally compressed body with upward directed mouth. It has centrally located eyes and thin elongate mandibles with a protrusive lower jaw. The body of this Zebrafish contains incomplete lateral line and two pairs of barbells. There are five uniform pigmented horizontal blue stripes on the side the body which resembles of zebra`s stripes that extend to the end of the caudal fin.  Anal fin is distinctively striped with 10-12 branched fin rays. It is omnivorous fish and in the wild condition its food chiefly consists of zooplankton, algae, vascular plants, spores, insects, insect larvae, invertebrate eggs and variety of other foods such as worms and small crustaceans. It also takes food from surface area of the water such as terrestrial insects and arachnids.  In wild condition, the GloFish®is preyed upon by snakeheads, freshwater garfish, catfish, knifefish, spiny eels, Indian pond heron and common kingfisher. The zebra fish can grow up to 7.6 cm in length and its life span ranges from 2 to 5 years.

Scientific Name: Danio rerio

English Name: Red Danio, Green Danio, Orange Danio, Blue Danio, Purple Danio

Origin:  India to Bangladesh

Adult Size: Up to 3 inches (7.6cm)

Behavior: Peaceful

Tank Level: Middle to Top levels of the tank

Minimum Tank Size:  15 gallons or larger

Diet: Omnivore

Breeding: Egg layers.

Care level: Easy

Water pH: 6.5-8.0

Water Hardness: 5-19° dH

Water Temperature: 65°F – 75°F

Water Movement: Weak

Lighting:  Moderate – normal lighting

Compatible Tank Mates: Glofish can be kept with other danios, barbs, tetra, angelfish and other freshwater fish species which are similar in size.

Lifespan:  up to 5 years

Housing GloFish®

GloFish® are hardy fish and considered good for beginner aquarium hobbyists. This fish adapts to most aquarium conditions. At least 15 gallons or larger tank is required to keep your Danio rerio healthy and happy. They also do well in schools or shoals of six or more individuals. They spend most of their time in the top and middle regions of the tank. This is a peaceful fish and should be housed with other peaceful fish such as other danios, barbs, tetra, angelfish and other freshwater fish species which are similar in size. Aquariums are closed systems and it always needs some maintenance. Organic matter, nitrates and phosphate build up overtime in the aquarium and the water hardness increases due to evaporation. Proper care should be taken and 25-50% of the tank water should be replaced at least once a month. If the tank is densely stocked, 20-25% water should be replaced weekly or every other week. The aquarium needs good filtration system to provide sufficient water movement and the tank should be covered with lid as this fish may jump.

Recommended Plants

Check out recommended plants for GloFish®

Feeding GloFish®

The GloFish®GloFish or zebrafish is omnivorous and they gets their food from the water column that chiefly eats zooplankton, algae, vascular plants, spores, insects, insect larvae, invertebrate eggs and variety of other foods such as worms and small crustaceans. GloFish® also takes food from surface area of the water such as terrestrial insects and arachnids. In the aquarium they eat most any prepared or live aquarium foods. Standard tropical flake food should be fed in small batches 2- 3 times per day. They also take freeze-dried shrimp. A variety of feed should be fed for best health of your GloFish®. Fry can initially be fed live Paramecium or other microorganisms. At around day 9 they can be fed brine shrimp.

Breeding GloFish®

Danio rerio is considered easy to breed in aquarium. It is group spawners and egg scatterers. It is active and social fish which breeds seasonally during the monsoons that ranges from April to August. It tends to breed in silt-bottomed and well vegetated pools. In captive condition gravel spawning sites are preferred to silt spawning sites. Water temperature (78°F) of the aquarium should be maintained and feeding the female with high quality foods. The female lays 100 non-adhesive eggs without preparing a nest in each clutch at intervals of 2 to 3 days.  The Zebrafish spawns every 1 to 6 days during spawning season that occurs once yearly.  Breeding is influenced by temperature and food availability also acts as cue for breeding. Hatching time also depends on water temperature which should be 83.3 °F.  The most eggs hatch between 48 and 72 hours after fertilization.  Hatchling is approximately 3 mm in size and becomes immediately independent. They are able to swim, feed and exhibit active avoidance behaviors within 36 to 72 hours of fertilization.

Sexing GloFish®

The male GloFish® are hard to distinguish from the  female during juvenile stage but at adult stage it is easy to make differences between the male and female GloFish®.  The male has torpedo-shaped body with gold stripes between the blue stripes while the female has a larger whitish belly and silver stripes instead of gold stripes. The male also have more yellow coloration and larger anal fins than females. Adult females exhibit a small genital papilla in front of the anal fin origin. During breeding time female develops a more pronounced stomach when carrying eggs.

GloFish® for sale & Where to buy

The GloFish® are readily available in stores and online vendor under the trade name zebra danio. A variety of different GloFish® are currently on the market and are now sold in bright red, green, orange-yellow, blue, and purple fluorescent colors. Look below for online vendors to buy your favorite color GloFish® that I personally would recommend from. NOTE: GloFish are ban in California for very odd reasons.