Vertebrate Zoology

Spring 2004 _ Exam I

  1. Draw a cladogram showing the relationships of the bony fish, cephalochordates (amphioxus), hagfish, lampreys, ratfish (chimaeras or holocephalians), sharks,tunicates. Each of these seven taxa will be at the tips of the 7_branched cladogram. Place the following apomorphic characteristics on the cladogram in the correct position (10 points)
    1. Bone
    2. Cranium with sense organs
    3. Hollow dorsal nerve cord
    4. Internal bony skeleton
    5. Jaws
    6. Pelvic and pectoral fins
    7. Placoid scales
    8. Replacement tooth rows
    9. Segmented body muscles present in adult.
    10. Three semicircular canals
    11. Vertebral column
 

a

b

c

d

e

f

g

h

i

j

k

bony fish

                      

cephalochordates

                      

hagfish

                      

lampreys

                      

ratfish

                      

sharks

                      

tunicates

                      

  1. Why are most sharks considered to be K_selected. (2 points)
  2. Why are hagfish considered to be K_selected. (2 points)
  3. Why are K selected species more likely to be overfished. (2 points)
  4. What factors are contributing to the overfishing of sharks? (2 points)
  5. What factors are contributing to the overfishing of hagfish? (2 points)
  6. Define and state the significance to vertebrate zoology as discussed in the material covered in lecture of any 5 of the following. Where appropriate state what taxon (_a) the term is associated with. (5 points each, 25 points total)
    1. Counter current exchange
    2. Deuterostome
    1. Neoteny
    2. Notochord
    3. Swim bladder
    4. Regional heterothermy
    5. Ostracoderm
    6. Slime glands
    7. Suction disk mouth
  7. In the Chondrichthians, discuss the significance of any five of the following (5 points each, 25 points total)
  1. Ampullae of Lorenzini
  2. Brain mass to body mass ratio
  3. Chemoreceptors
  4. Claspers
  5. Holostylic jaw suspension
  6. Intrauterine cannibalism
  7. Liver
  8. Spiracle
  9. Urea

Answer any THREE of the following (10 points each, 30 points total).

Discuss the life cycle of a typical lamprey.

How is a lamprey larva (ammocoetes) similar to a cephalochordate (Amphioxus)? How is it different?

Discuss and describe the diet and feeding behavior in hagfish.

Discuss the osmoregulatory problems and solutions of a fresh_water bony fish

Describe the feeding specializations in elasmobranchs with any THREE of the following diets. Give the (common) name of a species that fits into each category and name which of the three major subgroups of elasmobranchs it belongs to.

  • piscivore _ fish eating, tend to grab on & swallow whole
  • Durophagous, or hard/shell_fish eater
  • "meat_cutter" _ takes bites out of large prey
  • Filter_feeding
    •