Adult zebrafish are small in size and breed readily

Zebrafish adults are small, around 3-5 cm in length, and they like to be housed together in shoals. They are batch spawners capable of laying hundreds to thousands of embryos a week.

The eggs are externally fertilized

Female fish lay eggs into the water around her, where they are fertilized by the males, allowing collection the eggs as soon as they're laid.

Embryos develop quickly

They develop from a single cell in a fertilized egg to something that resembles a tiny fish in 24 hours. Once they are around 4-5 day post fertilization the embryos are free swimming larvae and start to catch their own food.

Embryos are transparent

The transparency of zebrafish embryos is one of the leading reasons for using them for scientific research. The ability to see through the embryos allows observation of morphological changes that occur during development.

Embryos can be genetically manipulated

Mutations can be generated and analyzed to see what happens when a gene’s normal function is altered.

Close homology to humans

Zebrafish are vertebrates and share many of the same genes as humans.

Other attractive characteristics

  • Fully-sequenced genome
  • Well understood, easily observable and testable developmental behaviors
  • Availability of well-characterized mutants
  • Drugs or chemicals may be administered by adding directly to the tank
  • Inexpensive compared to other vertebrate models

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