Brachydanio rerio

Brachydanio rerio, commonly known as the zebrafish, is a tropical freshwater fish belonging to the minnow family Cyprinidae. It is a popular model organism in scientific research due to its genetic similarity to humans and its transparent embryos, which allow for easy observation of developmental processes.

Description

The zebrafish is a small fish, typically reaching up to 4-5 cm in length. It is named for its distinctive horizontal stripes along the length of its body, which resemble a zebra's pattern. These stripes are thought to serve as camouflage and as a social signaling mechanism among fish.

Habitat

Brachydanio rerio is native to the streams and rice paddies of the Himalayan region, including India, Nepal, Bangladesh, and Myanmar. It prefers shallow, slow-moving waters with abundant vegetation.

Reproduction

Zebrafish are oviparous, with females laying hundreds of eggs at a time. Fertilization occurs externally, and the transparent embryos develop rapidly, hatching within three days. This rapid development, along with the large number of offspring, makes the zebrafish an ideal subject for genetic and developmental studies.

Use in Research

The zebrafish has become a powerful model organism in biomedical research. Its genetic makeup is remarkably similar to that of humans, with over 70% of human genes having a zebrafish counterpart. Researchers use zebrafish to study a wide range of biological processes, including development, genetics, disease mechanisms, and potential drug therapies. The transparency of zebrafish embryos allows scientists to observe developmental processes in real-time.

Genetics

The zebrafish genome has been fully sequenced, revealing approximately 26,000 genes. Genetic tools and techniques, such as CRISPR/Cas9 for gene editing, have been developed for use in zebrafish, facilitating the study of gene function and the genetic basis of diseases.

Conservation

While the zebrafish is not currently considered endangered, its natural habitats are threatened by pollution, habitat destruction, and climate change. Conservation efforts are important to preserve these ecosystems for the zebrafish and other species that share its habitat.

In the Aquarium

Beyond its scientific value, the zebrafish is also popular in the aquarium trade. It is prized for its vibrant colors and patterns, as well as its hardiness and ease of care. Zebrafish are social animals that do best in groups and require a well-maintained tank with plenty of space for swimming.