BB AALA Ch21 Fish

Question 1

1. Which Vertebrate has the highest number of distinct species?

Answer 1

Fish

Question 2

2. True or False: Freshwater species of fish absorb and excrete agents similar to saline and euryhaline species.

Answer 2

False

Freshwater species should be expected to absorb and excrete agents differently due to radical differences in their handling of ionic homeostasis, but these differences are not well studied.

Question 3

3. Which fish are the most challenging to anesthetize?

Answer 3

Fishes from pelagic (open sea) and fast flowing streams.

Question 4

4. Which association specifically defines and promotes the study of pain?

Answer 4

IASP= International Association for the Study of Pain

Question 5

What evidence suggests that fish do perceive painful stimuli?

Answer 5

1) Functional neurologic pathway for nociception
2) Reactive complex behavioral responses and learned avoidance behavior to noxious stimuli
3) Endogenous chemical modulation analogous to mammals

Question 6

Because fish lack the structure analogous to the mammalian ________, it has been argued that they do not feel pain.

Answer 6

neocortex

Question 7

7. Describe the endogenous opioid system in fish.

Answer 7

Kappa and mu receptors in the brain

Question 8

Describe nociception in fish.

Answer 8

Nociceptors respond to pressurer, prick, and heat, and subsequently activate the telencephalon (demonstrated in goldfish and trout).

Question 9

9. True or False: Fish can be acclimated to catch and transfer (“netting”) like mammals.

Answer 9

True

Question 10

10. True or False: Mesh nets are adequate to catch fish.

Answer 10

False. Stiff and abrasive, best would be to use bag nets or box traps

Question 11

11. True or False: Fasting is not recommended before anesthesia of fish.

Answer 11

False. 24hr fasting is recommended to avoid regurgitation

Question 12

12. True or False: Fish should be observed for 24 hours after anesthesia to confirm good recovery from anesthesia.

Answer 12

True

Question 13

13. Which route of administration is most commonly used for anesthesia in fish ?

Answer 13

immersion

Question 14

14. Where is the anesthetic used for immersion absorbed by the fish?

Answer 14

gills

Question 15

15. Which commonly checked parameter is most crucial for adequate anesthesia in fish?

Answer 15

dissolved oxygen

Question 16

16. Where are IM injection usually performed?

Answer 16

above the lateral line under the dorsal fin

Question 17

17. True or False: For long surgeries, a method of continuous flow of well aerated anesthetic water over the gills is needed.

Answer 17

True

Question 18

18. Where are IP injections usually given in fish?

Answer 18

between pelvic fin and anus with needle angled forward on midline

Question 19

19. What is the least damaging way to handle fish?

Answer 19

Wet latex or nitrile gloves

Question 20

20. What signs are observed to monitor and assess the depth of anesthesia?

Answer 20

Rate and strength of opercular movement
Movement of the fish
Righting reflex
Menace reflex

Question 21

21. For immersion anesthesia, where should the water come from to prepare the anesthetic immersion solution?

Answer 21

The original tank if clean

Question 22

22. True or False: The ideal anesthetic depth in fish is a compromise achieving slow, steady and effective opercular movement without response to stimulation.

Answer 22

True

Question 23

23. True or False: Once anesthesia is no longer needed, the fish is placed in a well aerated, anesthetic-free water (ideally from the original tank) and manual movement of the fish can be used to force water through the gills.

Answer 23

True

Question 24

24. What are the “best practices” anesthetic agents used as an immersion solution in fish, as reported by the AALA?

Answer 24

Tricaine methanesulfonate (MS-222, TMS, Metacaine, Fiquel)

Quinaldine sulfate

Imidazole anesthetics (metomidate, marinil, methomidate, etomidate, amidate, R7464) - not ideal in most cases but may have specific use in certain situation

(Eugenol - approved for use in fish in Australia, New Zealand, Chile, Korea)

Question 25

25. What are the best practices injectable anesthetic agents used in fish?

Answer 25

Ketamine

Alpha-2 agonists

Propofol

Question 26

26. Which anesthetics are not recommended for use in fish?

Answer 26

Diethyl ether
Chloral hydrate
Urethane
Halothane
Chlorobutanol

Question 27

27. True or False: Imidazole anesthetics are stress-free anesthesia agents.

Answer 27

False

Question 28

28. True or False: Immersion of fish in a tricaine solution has been shown to produce physiological changes: increase in cortisol, glucose, hematocrit and lactate.

Answer 28

True

Question 29

29. True or False: Tricaine is more potent in warm and soft water.

Answer 29

True

Question 30

30. What is the withdrawal time after use of tricaine in fish?

Answer 30

21 days

Question 31

31. Which anesthetic agent is the only approved by the FDA?

Answer 31

Tricaine

Question 32

How should Tricaine be stored?

Answer 32

refrigerated, protected from light, +/- freezing

Question 33

33. True or False: Tricaine does not need to be buffered

Answer 33

False

At concentrations of 100 mg/ml, pH can be as low as 5. Should be buffered with sodium bicarbonate to pH 7-7.5.

Question 34

Describe analgesic use and agents in fish.

Answer 34

Teleost fish have mu and kappa opioid receptors.

Butorphanol is kappa opioid agonist and has been shown to preoperatively prevent behavioral changes in koi carp suggesting decreased pain or stress or both.

Morphine is mu agonist, and has been shown to attenuate post-op behaviors and decrease operculum rate in rainbow trout following noxious stimulus.

NSAIDs did NOT prevent behaviorla changes following noxious sti,uli in koi carp, but did attenuate creatinine kinase changes indicating diminished muscle injury.

Question 35

35. True or False: Electroanesthesia and hypothermia are 2 acceptable anesthesia options.

Answer 35

False