Fishes

Question 1

Neural crest cells

Answer 1

embryonic cells only found in craniates, arise between ectoderm and neural tube

Question 2

Derivations from neural crest cells

Answer 2

unique to craniates

lower jaw, dentin of teeth, some neurons, meninges (brain covering), Schwann cells

Question 3

Vertebral column

Answer 3

separate bones/ blocks of cartilage, allows larger, more active swimmers and protects nerve end

Question 4

Craniate and vertebrate evolution

Answer 4

evolved during Cambrian explosion, no fossil evidence among Ediacarans

Question 5

Early forms looked for in Fossil Record

Answer 5

cranium, vertebrae, tissues derived from neural crest cells

Question 6

Conodonts

Answer 6

Toothlike elements have been known from fossils since 1840s, 1980s animal associated found with them. ~500-200mya

Question 7

Hagfishes (Myxini)

Answer 7

Invertebrate, not considered fish. Cartilaginous notocord, eyes, carnium, ears, nasal openings, eat dead fish, invetebrates, worms.

Question 8

Hagfish slime

Answer 8

makes skin slippery to evade predators, clogs gills of predators

Question 9

Lamprey (Petromyzontida)

Answer 9

Vertebrates, vertebral column homologous to ones of other vertebrates. no scales and paired fins, lack bone (ancestral or derived), suck blood from live host

Question 10

Cartilaginous fishes (chondrichthyes)

Answer 10

Gnathostomes-jawed vertebrates, jaws from repositioning of skeletal rods supporting gill openings

Question 11

Suspension feeding chondrichthyan

Answer 11

Whale Shark

Question 12

Oviparous

Answer 12

egg hatches outside mother. embryo nourished by egg nutrients

Question 13

ovoviviparous

Answer 13

egg hatches intisde uterus, embryo nourished by egg nutrients

Question 14

viviparous

Answer 14

embryo nourished in uterus by placenta or uterine secretions

Question 15

Bony fishes (actinopterygii) Ray Finned Fishes

Answer 15

swim bladder, allows density adjustment. evolved in freshwater. swim bladder derived from ancestral lung to help freshwater forms live in stagnant ponds

Question 16

Sarcopterygii Lobe Finned Fishes

Answer 16

bony skeleton extends into pectoral and pelvis fins, larger bones and sturdier muscles

Question 17

Dipnoi Lungfishes

Answer 17

have gills as well