How To Breed Zebra Fish “Danio Rerio”

zebra fish

Zebra fish are a species of fish that have been used in research for decades. They can be found all over the world, particularly in warm climates. These animals reproduce very quickly and easily.

This makes them ideal candidates to use in experiments where they will need to procreate before being killed or fixed up with an injury so their development is studied. They are also small fish making them easy to handle for lab experiments where they may be exposed to chemicals or radiation.

They have a transparent body, allowing scientists to visualize the inner workings of their organs and how genetic mutations affect development in real-time. Scientists can observe these changes as they occur rather than waiting weeks or months for the results. This ability has led to a number of important discoveries about human development and disease, including the discovery that heart attacks do not need oxygen for damage to occur.

Origin and descriptions

zebra fish

The zebra fish is a species of freshwater fish belonging to the minnow family, Cyprinidae. Native to the Himalayan region, it has been introduced to parts of Europe and America where they are sometimes considered an invasive species. They are also found in pet stores as well as being studied by scientists worldwide due to their transparency and the fact that they breed easily.

There are many different breeds of zebra fish, which can be grouped into three main types: wild type (the “normal” fish), black molly, and leopard danio.

These fishes have an omnivorous diet consisting mostly of phytoplankton as well as some protozoa, depending on their age. They have a long lifespan and grow to around 11 cm (almost five inches) in length, although the maximum recorded size is 12.0 cm (four-and-a-half inches).

They can be distinguished from other species of fish by the presence of three black bars that run horizontally across its body behind its gills. These black lines can be any number of different shapes and are unique to the individual fish, much like human fingerprints.

Zebra fish has been an important scientific model organism for biomedical research since it was first introduced into science in 1938 by George Streisinger from the University of Oregon using wild-caught specimens imported from India.

Species profile

zebra fish

Zebra fish are native to the streams of India, Pakistan, and Bangladesh. The zebrafish has been used extensively in research for decades due to their biological similarities with humans, including transparent embryos that allow observation throughout development.

They have also recently emerged as a model organism in quantitative genetics due to rapid advances in imaging technology which allows automated measurements across many individuals and generations. The zebra fish genome has also been sequenced, which provides exciting opportunities for finding the genetic basis of genomic data.

Zebra fish are now one of the most popular vertebrate species used in research due to their rapid development cycle and transparency during embryogenesis allowing observation at all stages as well as ease of housing and feeding.

Zebrafish scientific name

The scientific name for zebra fish is Danio rerio

Color and appearance

Zebra fish are named for their characteristic stripes and coloring. They have a pale brown or gray body with several dark vertical lines running from head to tail, which is why they were initially called the “zebra fish”. Over 200 distinct color patterns exist among zebrafish, although albino varieties lack pigmentation and display white instead of black stripes.

Zebrafish are typically dark brown or black with light horizontal stripes running down their sides. They have pinkish-white bellies and grayish-white edges on the dorsal fins. The fish has an upturned mouth which helps it to feed on the surface of the water as well as pick food out from between tiny crevices in rocks or plants.

Zebrafish are mostly found in blackwater rivers throughout Southeast Asia, especially Malaysia and Thailand where they live near the surface of sandy substrates or along banks covered with vegetation. They prefer slow-moving water but can also be found in dams and rice paddies that have shallow areas for them to feed in without being swept away by currents.

Range and habitat

Zebrafish are native to Thailand, Malaysia, and Indonesia. They have also been introduced all over the world where they can be found in warm, slow-moving waters such as ponds, rivers, or rice fields.

They prefer shallow water with low currents so that they can feed easily without being swept away by fast-moving tides or waves. Zebrafish live in a range of water temperatures from 16 to 25 degrees Celsius, but they can tolerate colder or warmer waters as long as the change is gradual.

They typically feed on invertebrates and insect larvae that dwell between cracks on rocks or within plants along the surface of their habitat. They also eat algae and other aquatic vegetation found growing in their habitat.

Zebra fish are most active during the day, but they will also come out to feed at night when there is less light available for aquatic plants and animals in their environment. They tend to form small groups according to age or size within a species, with larger members of each group eating before smaller ones do so that they are not out-competed for food.

Zebrafish size

Zebra fish grow to an average length of six inches and a maximum length of seven inches. Females are generally larger than males, but not too much as they only differ in size slightly.

Tank size

Zebra fish require a tank with plenty of surface area for them to make nests and feed from. They prefer slow-moving water about 12 inches deep, but they can also be kept in shallower waters as long as there are areas where the fish can take refuge such as plants or rocks.

Life cycle of zebrafish

The first stage of life cycle for zebrafish starts when an egg hatches into a larva. These larvae are transparent with gills on both sides of their head. They also have a long, stiff tail with fins on either side that help them swim around in the water. The larvae then grow into juveniles within just about three weeks, which is known as metamorphosis.

With this transformation comes many developmental changes including having gills instead of lungs and scales covering their bodies to protect them from the water. They also gain a tail and fins, as well as eyes that can see shapes and movement around them.

The next stage of the life cycle is where zebrafish become adults. The adult phase starts with the metamorphosis from the juvenile stage to an adult fish which happens in just three weeks time. During this period, they develop their adult color pattern and a full set of scales. They also develop the ability to breathe through their gills or lungs depending on what kind of environment they are in.

The last stage for zebrafish is when they become old adults. This phase includes developing large gonads which store sex cells, as well as increased fat storage throughout the body. The fat reserves are used as a food source during breeding and help the fish become more attractive to potential mates.

Are they aggressive or peaceful?

Zebra fish are very peaceful animals that rarely get into fights. They don’t show any aggressive behavior to each other even when they feel threatened or hungry.

Zebra fish care

zebra fish

Zebra fish care can be difficult. The water temperature must stay between 70 and 80 degrees Fahrenheit, the pH should range from seven to eight, and nitrates can’t exceed one-hundred parts per million (ppm).

Zebrafish diet

Zebrafish are omnivorous, so feed them a variety of vegetables and protein foods. Feeding your fish will depend on the life stage they’re in: fry (babies), juveniles, or adults.

Fry need live brine shrimp every day because their stomachs are too small for dry food. Juveniles should be fed brine shrimp and daphnia two or three times a day, as much as they can eat in five minutes.

Adult Zebra fish need to have their diet changed from live food to dry flake food every now and then so that they get different nutrients than what the live foods provide them with.

Tank mates

Zebra fish are best kept with other zebra fish, but bottom dwellers like Corydoras catfish make good tank mates. Avoid keeping them with large or aggressive fish that might eat them.

Water conditions

Zebra fish are freshwater fish and need clean water. Weekly, check the pH level of your tank’s water with a test kit to make sure it stays in the range of seven to eight.

Replace one-fourth of the tank’s water every week and perform 20% changes twice a month by siphoning up the gravel with a cup, taking out one-fourth of water, and adding fresh dechlorinated tap water.

Use an appropriate tank filter to keep ammonia levels low; if it becomes too high, your fish will become sick or die.

Zebra fish breeding

zebra fish

Zebrafish breed easily in warm water with a pH of eight. Males follow the female around until she lays her eggs, then they fertilize them after she picks up each individual egg to lay it somewhere else.

After about three days, the fry will hatch and can be fed by crushing flake food into a powder so that they get the nutrients they need.

Zebrafish lifespan

A zebrafish’s average lifespan is between three and five years but can survive up to 15 years in captivity.

Parasites and diseases

Zebra fish are susceptible to parasites and viral diseases. Some of the common ones include:

  • Ichthyophthirius multifiliis, which causes “ich” or white spot disease
  • Chilodonella sp., which is a single-celled organism that can attack the skin cells on zebrafish causing ulcerations.
  • Aeromonas rettgeri, which causes hemorrhagic septicemia in the bloodstream.

Most of these parasites and diseases are easily treated with antibiotics or copper sulfate, but cannot be cured if they have reached an advanced stage. Treatment is most effective when treatment can begin immediately after noticing symptoms of infection on the fish.


Zebrafish are prey to many different types of predators. Some examples include:

Zebra fish are also prey to many different types of predators in their natural habitats too. For example, birds (eagles) eat them while they’re swimming around the water’s surface or on land during mating season when they can’t swim away fast enough. They also fall victim to crocodiles, large fish, and snakes.

Does it make good pets?

Yes. Zebra fish make good pets as they are very hardy and easy to breed. They can live in a small tank with minimal equipment, do not require daily feeding (every other day is fine), and stay at the top of the aquarium so you won’t have issues with getting waste on your floor.


Zebra fish are a very popular aquarium fish because of their hardy nature and are easy to care for. They have been used in scientific research due to the fact that they breed quickly, grow rapidly, eat easily lab-produced food, and can be genetically altered through selective mating or CRISPR technology.

They also make good pets as you only have to feed them every other day, they stay at the top of your aquarium so you won’t have issues with wastes on your floor and can live in a small tank.