ANSWERS

1. Frogs and toads are amphibians. To which order do they belong?
   The order anura.
2. Newts and salamanders are amphibians. To which order do they belong?
   The order urodela.
3. Amphibians are ectothermic. What does this mean?
   They are unable to control their body temperature intrinsically, but reflect ambient environmental temperature.
4. Ectothermic animals have their own preferred body temperature (PBT). What is meant by this?
   The PBT is the temperature range at which physiological actions (locomotion, feeding and action of digestive enzymes) are at their optimum.
5. Amphibians are usually oviparous. What does this mean?
   Eggs are laid.
6. List 6 characteristics common to amphibians.
   
   • Possession of an internal skeleton (vertebrates).
   • Ectothermic (see Q3).
   • Possession of moist skin.
   • Usually oviparous (but occasionally may be ovo-viviparous which means that eggs are retained within the body of the female until the young are fully developed and able to lead an independent life).
   • Larval form (lungs present in the adult, gills present in the larval form).
   • External fertilisation.
7. State 2 species of toad.
   
   • Common toad (Bufo bufo).
   • Marine toad (Bufo marinus)
     (There are, of course, many others).
8. State 2 species of frog.
   • European tree frog (Hyla arborea).
   • Edible frog (Rana esculenta).

   (There are, of course, many others).

9. State 1 species of newt.
   • Great-crested newt (Triterus cristatus).
10. State 1 species of salamander.
    European salamander (Salamandra salamandra).
11. What is the Latin name for the order of fish?
    Pisces.
12. List 6 characteristics common to all fish.
    Internal skeleton (vertebrates).
    
    • Ectothermic.
    • Moist skin with scales.
    • Possession of gills.
13. State 3 characteristics that may vary in different species of fish.
    
    • May or may not possess a larval form.
    • Means of fertilisation (usually external).
    • May be oviparous or ovo-viviparous.
14. State the 3 main groups of fish.
    
    • Placoderms (primitive fish).
    • Osteichthyes (bony fish).
    • Chondrichthyes (cartilaginous fish).
15. List 8 considerations to be taken into account with regard to successful fish keeping.
    
    • Water temperature (cold-water or tropical).
    • Water type (salt-water or fresh-water).
    • Filtration device to keep the water clean.
    • Adequate oxygenation by means of plants and an air pump.
    • Suitable nutrition.
    • Only keep compatible species together.
    • Quarantine facilities necessary for sick fish/breeding/introduction of new fish.
    • Correct water pH, dechlorination, keep aquarium clean.
16. How long should a new fresh-water aquarium be left to "settle" prior to adding fish?
    2 Weeks.
    NB. Salt-water aquaria are much more complicated and take months of preparation before fish can be introduced.
17. Why is over-feeding of fish detrimental?
    Fish will eat continuously given the chance and will digest what is required and excrete any surplus. Excessive excretion causes a nitrite build up that will cause water quality problems and pollute the tank.
18. What are young fish called?
    Fry.
19. What is the common name for Ichthyopthirius infection that may affect amphibians and fish?
    White spot.
20. What is the name of the proprietary medicine often used to treat white spot?
    Malachite green.
21. State 2 causative organisms of tuberculosis in fish.
    
    • Mycobacterium marinum.
    • M. fortuitum.
      
      NB. Tuberculosis is a zoonotic disease and therefore suspect carriers must be handled with caution.
22. Describe the anaesthesia of amphibians and fish.
    
    • Select a suitably sized induction tank.
    • Fill the induction tank with a dilute solution of tricaine methane sulphonate or benzocaine according to the manufacturer's instructions (make sure the solution is deep enough to immerse the fish or submerge the amphibian up to nostril level).
    • Place the patient in the solution are carefully monitor vital signs (rate of induction is very variable).
    • Aim for sedation rather than anaesthesia, and once the patient has reached a state of minimal activity remove from the tank and place on a cool damp towel.
    • Cover the head, tail and gills with moistened swabs.
    • The surgical procedure may then be performed (if variation in the depth of anaesthesia is necessary, syringe oxygenated water or anaesthetic solution onto the animal and in particular the gills).
    • Once the procedure is complete, the animal is to be transferred to a recovery tank containing clean oxygenated water.
    • In species with gills, encourage movement and opening of the mouth for a swifter recovery.
23. List 3 characteristics common to both arthropods and molluscs.
    
    • Invertebrates.
    • Open vascular system.
    • Oviparous or viviparous.
24. List 5 examples of members of the arthropod group.
    
    • Emperor scorpion (Pandinus imperator).
    • Indian stick insect (Carausius morosus).
    • Red kneed tarantula (Euthalus smithii).
    • Tree bird spider (Avicularia spp.).
    • Tree crab (Coenobita spp.).
25. State 1 example of the mollusc group that may be kept as a pet.
    African land snail (Achatina spp.).
26. State the predominant diet for the following species: Indian stick insect, giant millipede, African land snail & red-kneed tarantula.
    
    • Indian stick insect - privet leaves.
    • Giant millipede - dead leaves, fruit, vegetables & other organic matter.
    • African land snail - fruit, vegetables & a calcium source.
    • Red-kneed tarantula - insects.
27. What is the correct name for the irritant hairs possessed by the red-kneed tarantula?
    Setae.