Danio rerio ( zebra fish) introduction & Morphology

The zebrafish (Danio rerio) is a freshwater fish belonging to the minnow family (Cyprinidae) of the order Cypriniformes. Native to India and South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a "tropical fish" although both tropical and subtropical).

1. University of Chakwal, Pakistan

2. Topic:Zebra Fish Department of Zoology
Presented by: Komal Zahra
Roll no# UOC-BSZOL-F2020/035
BS Zoology
Session: 2020-2024
Subject: Ichthyology
Instructor Name: Dr. Syeda Nadia Ahmad

3. Introduction The zebrafish is one of the model organisms for genetic and
developmental studies. The scientific name of zebrafish is Danio rerio The zebrafish ( Danio rerio ) Is a freshwater fish it belongs to the minnow family, Cyprinidae . Native to India and South Asia also found in private ponds. Fig.1 Zebra fish https://images.app.goo.gl/dbRs3W4LU1PjTFfp7

4. Zebrafish grow to maturity and are able breed within 2 to 3 months. Got its common name from the presence of five uniform and pigmented horizontal stripes on the side of its body. Stripes of zebrafish are blue in colour and they extend from the gill cover to the end of the caudal fin. Zebrafish has been used for biomedicine and developmental biology. ( Metscher , B. D., & Ahlberg , P. E. 2014). Fig.2 Zebra fish https://images.app.goo.gl/vH5GGVrc4GLtn957A

5. Taxnomy : Domain: Eukaryota Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Cypriniformes Family: Cyprinidae Subfamily: Danioninae Genus: Danio Species: D. rerio

6. Binomial Names: Barilius rerio Cyprinus chapalio Brachydanio rerio Cyprinus rerio Danio lineatus Nuria rerio Perilampus striatus (Broughton, R.,2016 )

7. General Characteristics: Body Shape: Its shape is fusiform and laterally compressed, Mouth Shape: Mouth directed upwards. Tail: Forked tail Fins: Dorsal, pectoral, pelvic,Anal , Cadual Type of scales: Elasmoid scales

8. Meristic Characterstics : Feeder: Zebrafish are primarily carnivorous ( zooplankton, insect larvae, and small crustaceans in the wild) Migrate: they don’t migrate in the same sense as some other species. Growth rate: The growth rate of zebrafish can vary depending on factors such as genetics, environment, and diet. Life span: 2 to 3 years Weight: between 0.1 to 0.5 grams Natural predators: (predatory cichlids, snakes, birds, and aquatic insects.)

9. Fin formula: Dorsal fin rays: 8 to 9. Pectoral fins rays: 11-12 rays. Pelvic fin rays: 6-7 rays. Anal fin rays: 8 to 9. Cadual fin rays: 15 or more rays. Lateral Line scales: 32-35

10. Distribution: Native to India and South Asia also found in private ponds. Countries such as India, Bangladesh, Nepal, Myanmar, and Pakistan. Slow-moving or stagnant waters, including streams, ponds, ditches, and rice paddies. Often found in shallow waters with sandy or muddy substrates and dense aquatic vegetation. Zebrafish have been introduced to various parts of the world beyond their native range. (Broughton, R.,2016)

11. Importance of Zebra fish: Economic Importance of Zebra fish: Indicator Species Prey Species Control of Insect Populations: Nutrient Cycling Seed Dispersal Biodiversity Maintenance: Research on Aquatic Ecology.(Tavares, B., & Lopes, S.,2019) .

12. Biological importance of Zebra fish: Genetic Similarity to Humans Embryonic Development Regenerative Abilities Drug Discovery and Toxicology Neuroscience Cardiovascular Research Cancer Research Environmental Biology .( Tavares, B., & Lopes, S.,2019 ).

13. Interesting or Unique facts about Zebra fish: Origin and Habitat Distinctive Stripes Genetic Optical Clarity Regenerative Abilities Social Behavior Drug Discover Developmental Biology Environmental Sensitivity Educational Tool Short Reproduction Cycle Optogenetics .( Pritchard, V. L. 2017).

14. Morphology of Zebra fish: Mouth: The mouth of zebrafish is located ventrally and is terminal, Zebrafish have well-defined lips surrounding the mouth opening, Zebrafish possess two sets of jaws – the upper and lower jaws, which are lined with small, pointed teeth Fig.3 Zebra fish Mouth https://images.app.goo.gl/W8n3vfjjizGndD1SA

15. Oral cavity
Zebrafish have pharyngeal teeth located at the back of the throat.
Along the inner side of the gill arches, zebrafish have gill rakers Zebrafish mouths are adapted for omnivorous feeding habits

16. Scales: The zebrafish , Danio rerio , has a streamlined body covered in overlapping scales called dermal scales. These scales are composed of bone-like material called dentin covered by a thin layer of enamel. the coloration and patterning of the scales vary between different strains and individuals Fig.4 Zebra fish scales https://images.app.goo.gl/JNzo628RBCGFkEi5A

17. Fins: Caudal Fin (Tail Fin) Dorsal Fins Anal Fins Pelvic Fins Pectoral Fins Fig.5 Zebrafish fins https://images.app.goo.gl/ZQiHfgxQP6iHZzSw5

18. Behavior: Migratory Behavior: In the wild, they migrate in response to environmental cues such as temperature changes, photoperiod, and food availability. These migrations are essential for their survival and reproduction. Zebrafish larvae, for example, may migrate towards warmer waters or areas with higher food abundance. (Spence, R., Gerlach , G.,2019)

19. Parental Behavior: caring for their eggs and offspring. After spawning, the male fertilizes the eggs. role in guarding and maintaining the nest. fan the eggs with their fins to ensure proper oxygenation and remove debris. defend the nest against potential (Spence, R., Gerlach , G.,2019)

20. Recent research findings: Genetic Studies Disease Modeling Drug Screening Neuroscience Regenerative Medicine Environmental Studies(Spence, R., Gerlach , G.,2019)

21. References: Metscher , B. D., & Ahlberg , P. E. (2014). Zebrafish in context: uses of a laboratory model in comparative studies. Developmental biology, 210(1), 1-14. Broughton, R. E., Milam, J. E., & Roe, B. A. (2016). The complete sequence of the zebrafish ( Danio rerio ) mitochondrial genome and evolutionary patterns in vertebrate mitochondrial DNA. Genome research, 11(11), 1958-1967. Spence, R., Fatema , M. K., Reichard , M., Huq , K. A., Wahab , M. A., Ahmed, Z. F., & Smith, C. (2018). The distribution and habitat preferences of the zebrafish in Bangladesh. Journal of fish biology, 69(5), 1435-1448.

22. Tavares, B., & Lopes, S. S. (2019). The importance of Zebrafish in biomedical research. Acta medica portuguesa , 26(5), 583-592. Spence, R., Gerlach , G., Lawrence, C., & Smith, C. (2019). The behaviour and ecology of the zebrafish , Danio rerio . Biological reviews, 83(1), 13-34. Pritchard, V. L. (2016). Behaviour and morphology of the zebrafish , Danio rerio (Doctoral dissertation, University of Leeds). Brittijn , S. A., Duivesteijn , S. J., Belmamoune , M., Bertens , L. F., Bitter, W., De Bruijn , J. D., … & Richardson, M. K. (2018). Zebrafish development and regeneration: new tools for biomedical research. International Journal of Developmental Biology, 53(5-6), 835-850.