Lab Exam - Identification

Question 1

Amphioxus

Answer 1

• Oral hood with tentacles
• Notochord extends to tip of head
• Many pharyngeal slits

Question 2

Ascidiacea

Answer 2

Larvae undergo metamorphosis

In larvae:

• Notochord present
• Tail present
• Eye spots present
• Fewer paired pharyngeal slits than in adult

Question 3

Larvacea

Answer 3

Do not undergo metamorphosis

Adults resemble larvae but with a well-developed gut

Question 4

Myxiniformes

Answer 4

• Tongue with two rows of keratinized tooth plates
• 1-16 gills
• Fin-like structure running along ventral surface
• Feeler whiskers under the mouth

Question 5

Petromyzontiformes

Answer 5

• Mouth has oral disc with keratinized tooth-like structures (circular)
• 7 gills that look like holes
• Caudal fin along post-anal tail

Question 6

Ammocoete

Answer 6

Looks very similar to amphioxus, except:

• Notochord does not extend to the tip of the head
• No cilia/tentacles on oral hood
• Post-anal tail has caudal fin
• Only 7 gill slits

Filter feeder (adult is not!)

Question 7

Selachii

Answer 7

• 5-7 gills
• Spiracle
• Heterocercal tail
• Relatively small pectoral fins
• Hyostylic jaw

Question 8

Sharks

Answer 8

• Covered in placoid scales
• Multiple rows of teeth within the jaw
• Teeth embedded in gums

Question 9

Rays & skates

Answer 9

• Spiracle enlarged and close to eye

- Gills on ventral side of body

Question 10

Holocephali

Answer 10

• Gills covered by operculum
• Long, whip-like tail
• Large pectoral fins
• Holostylic jaw

Question 11

Sturgeon

Answer 11

• Heterocercal caudal fin
• Spines present along back and sides
• Ventrally placed mouth
• Ctenoid scales

Question 12

Salmon/trout

Answer 12

• Homocercal caudal fin
• Mouth anteriorly placed
• Cycloid scales
• No spines

Question 13

Sunfish/bass

Answer 13

• Homocercal caudal fin
• Spiny rays on dorsal/anal fin
• Mouth anteriorly placed
• Ctenoid scales

Question 14

South American lungfish

Answer 14

• Very thin pectoral and pelvic fins
• Caudal fin runs along ventral and dorsal sides of tail
• Reduced gills

Question 15

African lungfish

Answer 15

• Thin pectoral and pelvic fins
• Caudal and dorsal fins fused, run along dorsal and ventral sides of tail
• Full aestivation

Question 16

Australian lungfish

Answer 16

• Normal lobed pectoral and pelvic fins
• Posterior end is a fat wedge shape
• Caudal fin along tail

Question 17

Neotenic Caudata

Answer 17

Metamorphosis is not completed, so adult looks somewhat like larvae

• Adult retains gills
• Tail resembled caudal fin

Question 18

True frog

Answer 18

• Tapered toes
• Road pupils
• Eyes dorsally placed
• Smooth skin
• No parotoid gland
• Tympanum around same size as eye

Question 19

Treefrog

Answer 19

• Bulbous tip of toes
• Elliptical pupil
• Laterally placed eyes
• Smooth skin
• No parotoid gland
• Small tympanum

Question 20

Toad

Answer 20

• Tapered toes
• Horizontal slit pupil
• Laterally placed eyes
• Wart-like structures present
• Parotoid gland present
• Tympanum same size as eye

Question 21

Caudata

Answer 21

• No annuli
• Limbs may be present, reduced, or partially absent
• Skull gracile
• Post-anal tail present

Question 22

Anura

Answer 22

• No annuli
• Limbs present
• Hindlimbs substantially larger than forelimbs
• Skull gracile
• Tympanum
• Vocal sac
• Post-anal tail absent

Question 23

Gymnophiona

Answer 23

• Annuli present
• Skull well ossified and fully closed
• Post-anal tail reduced or absent
• Eyes reduced
• Limbs absent
• Tentacles on face

Question 24

Rhynchocephalia

Answer 24

Look almost exactly like a lizard but does not have fully-developed hemipenes

Question 25

Chameleon

Answer 25

- Laterally compressed body - Prehensile tail - Independently mobile eyes - Zygodactyl - Projectile tongue

Question 26

Anole

Answer 26

- Dewlap on males - Well developed toe pads - Limited colour change (greens and browns only)

Question 27

Gecko

Answer 27

- No temporal arches - Nocturnal - Slit pupil - Subdigital lamellae - Tubercles - No eyelids (they lick their eyes)

Question 28

Skink

Answer 28

- Fish-like scales | - Tendency for limb loss and reduction

Question 29

Coral snake

Answer 29

If red and yellow bands touch, dat shit is POISON. Colour banding also goes all the way around the body (doesn't always in mimics)

Question 30

Lizard

Answer 30

- External ears present - Eyes present - Limbs present

Question 31

Snake

Answer 31

- External ears absent - Eyes present - Limbs absent

Question 32

Worm lizard

Answer 32

- External ears absent - Eyes absent - Limbs absent

Question 33

Alligator/caiman

Answer 33

- Lower teeth fit into pits in the upper jaw, so lower teeth are not visible when the jaw is closed - Snout relatively broad

Question 34

Ghavial

Answer 34

- Long, thin snout | - Many teeth, all thin and needly

Question 35

Crocodile

Answer 35

- Fourth tooth in lower jaw lies outside the upper jaw when mouth is closed - Generally, the snout is narrower than an alligator's and wider than a ghavial

Question 36

Duck

Answer 36

- Palmate foot - Strainer beak (?) - Sexual dimorphism present

Question 37

Eagle

Answer 37

- Raptorial foot type - Meat tearing beak - Sexual dimorphism absent

Question 38

Crow

Answer 38

- Ansiodactyl foot - Generalized beak - Sexual dimorphism absent

Question 39

Cormorant

Answer 39

- Totipalmate foot - Hooked beak - Sexual dimorphism unknown