Zebrafish Flashcards
How do you tell the difference between female and male zebrafish?
Females have a white underbelly, males are more streamlined and active
What are natural zebrafish conditions?
Found in shoals of 5-20 fish, in the ganges delta river
How should fish be set up, and how many eggs can they lay?
group breeding = no more than 8 fish (2:1 ratio female to male)
In paired tanks = no more than 1 male and 2 females
Can lay 300-400 fertilised eggs (2-300 is normal)
What age can fish be bred at, and why are dividers used (2)?
3-4 months
To prevent male aggression and to collect eggs at a specific time
At what age does quality of eggs begin to diminish, and why might fish not lay?
14 months
Egg bound, same sex, unhealthy adults, diseases
What do zebrafish eat?
Artemia - fed to fish 14 dpf
Paramecia - fed from 5 dpf
Rotifer (can be loaded with nutrients) - fed from 5 dpf
Ammonia and nitrate - how is this created, what are symptoms of poisoning?
Fish excrete ammonia, which is turned into nitrite by nitrosomonas bacteria, which is then turned into nitrate by nitospira bacteria. Nitrate reduces the ability of fish to absorb oxygen
Ammonia is a stressor at 0.5mg/l and fatal at 2mg/l
Brown blood disease symptoms include rapid gill movements and gasping at the surface of water
Conductivity - why, and what value (ms)?
400 ms
Keeping fish in a mildly conductive environment puts less stress on the body, so they lose less energy. Reduces incidence of disease
What temperature range can fish tolerate, and what are they kept in in the lab?
Can tolerate 6-42C, kept between 24-28C
What is the definition of poikilothermic
Fish do not regulate their own body temperature
How long does tricaine take to work on fish, and how is schedule 1 carried out?
Takes around 20-30 seconds to start affecting fish, and around 2-3 minutes to reach a plane of anaesthesia.
Observe fish until they lose balance in the water and gill movement slows
Which schedule 1 methods are suitable for fish?
COnfirmation of permanent cessation of circulation (removing the heart), destruction of the brain (sharp implement), confirming onset of rigor mortis (leaving the fish in tricaine for 2 hours and observing)
When might larval forms of zebrafish be considered protected?
If regulated procedures are performed on them with the intention of raising them past day 5
What is schedule 2?
Animals can only be obtained from designated breeding or supplying establishments
What might cause fish to rise to the surface and not hold their position in the water?
Swim bladder problem
