Zebra Fish

Question 1

Genus and species of zebra fish

Answer 1

Danio rerio

Family- Cyprinidae

Question 2

What gene is mutated in the zebra fish melanoma model?

Answer 2

BRAF
(driven by mifta promotor in p53 knock-out)
image in BB chap 20 p1019

Question 3

T or F. Aggression in zebra fish is highest at high population densities

Answer 3

F. Aggression is higher in lower density tanks. It is more difficult for them to maintain dominance hierarchy and territoriality at higher densities

Question 4

List some abnormal (maladaptive) behaviors in zebrafish

Answer 4

tight shoaling, erratic activity bursts, freezing, bottom dwelling.

Question 5

What are the appropriate water temperature and room temperature ranges for housing zebra fish

Answer 5

water temp= 75-82 (24-28)
room temp 78-81 (24-27)
(fluctuation of water, not more than +/- 1.5C per day)

Question 6

What might fish gasping or sipping at the water surface indicate?

Answer 6

low oxygen saturation in the water of the tank

recirculating systems should have 1 complete turnover/hour

Question 7

What is the appropriate pH range to house zebrafish?

Answer 7

pH of 7-8

Question 8

What does measuring conductivity in the water system determine

Answer 8

indirect (and imprecise) measure of salinity

Question 9

What is the appropriate conductivity range for zebrafish (measured in microseimens)

Answer 9

125-2500uS

Question 10

What is water hardness and what is the appropriate range?

Answer 10

• amount of calcium and magnesium salts in the water.
• kit actually measures CaCO3
• 80-220ppm (pretty hard)
• May need to add CaCO3 back to RO or distilled water

Question 11

Name the species of ammonia-oxidizing species that are likely to be found in the biofilter for aquatic systems

Answer 11

Nitrosomonas, Nitrospira, Nitrosococcus

NH3 to NO2

Question 12

Name the species of nitrite-oxidizing bacterial species likely be found in the biofliter of aquatic systems

Answer 12

Nitrospira, Nitrobacteria

NO2 to NO3

Question 13

What can be used to surface disinfect embryos that will be transferred to a new colony?

Answer 13

dilute bleach (20-50ppm) at pH 7.

Question 14

What is the primary hematopoietic organ of the adult zebra fish?

Answer 14

head kidney

Question 15

What drugs and technique are commonly used to anesthetize zebra fish

Answer 15

Trichaine methansulfate (MS-222) or eugenol (Clove oil) by immersion

Question 16

Name 2 pathogenic mycobacterial species of zebra fish

Answer 16

M. marinum, M. heamophilum
(opportunistic pathogens M. chelonae, M abscesses, M. fortuitous, M. peregrinum).
-M. chelonae most commonly found

Question 17

Which Mycobacterium species is zoonotic and responsible for the human diseases “fish tank granuloma”

Answer 17

M.marinum

Question 18

Give the characteristics of the bacterial fish pathogen Edwarseilla ictaluti

Answer 18

-gram negative rod

coagulative necrosis of spleen and kidney

Question 19

What is the etiologic agent of Motile Aeromonas Septicemia (MAS)

Answer 19

Aeromonas hydrophila (A. sobria)

• gram negative
• opportunistic

Question 20

What are the common clinical signs of infection with Aeromonas heydrophila

Answer 20

petechial hemorrhages of the skin, fins and oral cavity

Question 21

What is the etiologic agent of bacterial gill disease?

Answer 21

Flavobacterium (branchiophilum)

Question 22

Name the etiologic agents responsible for Microsporidiosis in zebra fish (most common zebrafish disease)

Answer 22

Pseudoloma neurophilia

Pleistophora hyphessobryconis

Question 23

How is microsporixdiosis diagnosed?

Answer 23

wet mount of tissue from brain, spinal cord, muscle

“bed-room slipper” spores (in vesicles)

Question 24

What is the etiologic agent of Ich?

Answer 24

Ichthyophthirius multifilis

Question 25

What is the cause of gas bubble disease?

Answer 25

Supersaturation of water with nitrogen or oxygen

• caused by faulty system that leads to air injection or pumping water from deep wells without gas-stripping
• see gas bubbles in fish- around eyes and under skin

Question 26

How is chlorine (toxic to fish) removed from treated municipal water sources

Answer 26

• 24hr period of aeration

- addition of commercial dechlorinater

Question 27

How is chloramine removed from treated water sources?

Answer 27

• cannot be removed by aeration
• filtered by activated carbon
• treatment with sodium thiosulfate (chemical neutralizer)

Question 28

List 3 types of neoplasia common in zebrafish

Answer 28

-Seminoma
-Intestinal tumors
-Ultimobranchial gland (analogous to C cells in human thyroid gland, similar in location too)
-spindle cell
Hepatocellular