Lec 10 part b

Question 1

Holocephali clades

Answer 1

Callorhynchidae

Chimaerida

Rhinochimaeidae

Question 2

Holocephali features

Answer 2

Teeth that form beak-like feeding aparatus

Elongate snouts for electroreception

Lack tesserae or scales

Question 3

Holocephali feeding

Answer 3

Feed on invertebrates and small fishes near the sea floor

Holostylic jaw suspension

Question 4

Holostylic jaw suspension

Answer 4

Palatoquadrate (P) fused to neurocranium (C)

Question 5

Holocephali reproduction

Answer 5

Mostly solitary off mating period

Males can carry cephalic clasper for copulation

Are oviparous

Maturity at 10-12 years

Question 6

Oviparous

Answer 6

Fertilized eggs develop outside the female body

Question 7

Elasmobranchii

Answer 7

Sister group of Holocephali

Question 8

Batomorphi 4 clades

Answer 8

Rajiformes (A)
Torpedoiniformes (B)
Rhinoplastiformes (C)
Myliobatiformes (D)

Question 9

Batomorphi features

Answer 9

Wide and depressed

Eyes positioned dorsally

Gills and jawed mouth are ventral

Anal fin lost

Dorsal fin modified into tail spine with one or more venom barbs

Pectoral fins well developed and fused to head

Question 10

Batomorphi swim in

Answer 10

Wave like motions of the pectoral

Question 11

Batomorphi feeding

Answer 11

Most are benthic (bottom dwelling)

Durophagy

Some are piscivorous and filter feeders

Hyostylic jaw suspension allows jaw to protrude in some

Question 12

Durophagy

Answer 12

Feeding on invertebrates with hard shells

Question 13

Batomorphi hunt with

Answer 13

Electric organs

Electroplax tissues derived from muscles on the branchial/gill arches

Active electrogenesis

Found in some members of Torpidiniformes

Question 14

Batomorphi reproduction

Answer 14

Some species are oviparous and some are viviparous

Question 15

Viviparous

Answer 15

Fertilized eggs develop in female

Oral feeding starts before birth

Question 16

Selachii

Answer 16

Sister group to Batomorphie

Question 17

Shared feature of Selachii and Batomorphi

Answer 17

Relatively long rostrum (portion of the cranium in front of the eye)

Subterminal mouth

Hyostylic for mobile and protrusible jaws

Large nasal capsules

Question 18

Squalomorphi five clades

Answer 18

Hexanchiformes (A)

Squaliformed (B)

Squantiformes (C)

Pristiophoriformes (D)

Echnorhiniformes (E)

Question 19

Sawfish

Answer 19

Member of Batomorphi

Gill positioned ventrally

Lack barbels as electroceptors on the nostrum

Question 20

Sawshark

Answer 20

Member of the Squalomorphi

Gill positioned laterally next to pectoral fin

Carrying barbels as electroreceptors on the nostrum

Question 21

Squalomorphi

Answer 21

Carry a distinct spiracle to assist ventilation

Some species have tapetum lucidum (eye shine)

Lack anal fin

Fins with cartilaginous fin spines- Assist in stabilizing fins during movement

Question 22

Hexanchiformes diagnostic features

Answer 22

Lack calcified vertebrae

Loss of anterior dorsal fin

Loss of fine spines

Question 23

Galeomorphi 4 clades

Answer 23

Heterodontiformes

Orectobiformes

Lamniformes

Carcharhiniformes

Question 24

Galeomorphi diagnostic features

Answer 24

Having small spriacle or none at all

Most species lose fin spine

Carrying anal fin

Some have tapetum lucidum

Question 25

Tapetum lucidum

Answer 25

Formed by plate like guanine crystals behind the retina in the eye Makes the eye shiny

Question 26

Selachii feeding

Answer 26

Carnivorous predators Active hunting Ambush hunting Found near ocean floor

Question 27

Selachii hunting tactics

Answer 27

Suction feeding Ramming Biting

Question 28

Suction feeding

Answer 28

Mouth is opened rapidly, creating negative pressure that sucks in water and prey

Question 29

Ramming

Answer 29

Predator swims rapidly with mouth open

Question 30

Biting

Answer 30

Predator closes jaw on prey

Question 31

Selachii reproduction

Answer 31

Many species are oviparous some are viviparous

Question 32

Selachii Lecithotrophy

Answer 32

Yolk supplies all necessary nutrients

Question 33

Selachii Matrotrophy

Answer 33

Additional nutrients are supplied by female through placental attachment

Question 34

Otodus megalodon

Answer 34

Likely in Galeomorphi Usually large teeth and body size

Question 35

Acanthodii

Answer 35

Stem-chondrichthyans in the Devonian Small in size Spikes on the ventral side Lack teeth Carry smooth scales made from bone and dentin

Question 36

Helicoprion

Answer 36

Teeth arranged in spiral whorl all in lower jaw New teeth rotate outward old teeth are retained