Topic 28 Clade Osteichthyans

Question 1

What is a fish

Answer 1

• Paraphyletic group of aquatic vertebrates that use gills for respiration
• Includes jawless fish, cartilaginous fish, and bony fish, but excludes tetrapods

Question 2

Bony Fish

Answer 2

− Class Osteichthyes

Question 3

Osteichthyans

Answer 3

vast majority of vertebrates belong to a clade of gnathostomes called Osteichthyans

Question 4

Clade Osteichthyans includes

Answer 4

bony fish and tetrapods (amphibians, avian and non-avian reptiles, and mammals)

Question 5

we informally call Aquatic osteichthyans

Answer 5

fish

Question 6

Nearly all extant osteichthyans have a _____endoskeleton

Answer 6

bony (ossified)

Question 7

Osteichthyans shared derived traits

Answer 7

1. lungs/lung derivatives
2. operculum (plate fo dermal bone that covers and protects the gill arches and gills)
3. maneuverable fins

Question 8

Lungs are present as a ____ in most bony fish

Answer 8

swim bladder (air sac that maintains neutral buoyancy in fish)

Question 9

Extant bony fish descended from
ancestors living in brackish water that had
___ and ___

Answer 9

simple lungs and gills

Question 10

A simple lung:

Answer 10

dorsal out pocketing of gut filled with gas, augments gas-exchange by gills

Question 11

Original simple lung modified into the _____ of most extant bony fish

Answer 11

swim bladder

Question 12

The swim bladder is homologous to lungs of ____

Answer 12

tetrapods

Question 13

buccal pump

Answer 13

Mouth and operculum function as valves to draw water over the gills

Question 14

can ventilate their gills while stationary

Answer 14

bony fish

Question 15

In bony fish _______ support paired maneuverable fins

Answer 15

Pectoral and pelvic girdles

Question 16

Fins are supported by:

Answer 16

muscle and NOT the vertebral column

Question 17

Characteristics of extant bony fish

Answer 17

• Fully ossified (bony) endoskeleton.
• Bony fish have a lateral line system.
• Dermal armor is reduced to relatively thin, plate-like bony scales

Question 18

oviparous

Answer 18

produce eggs that hatch after being laid (most bony fish are oviparous)

Question 19

Two groups of extant bony fish

Answer 19

• Ray-finned fish (Fins supported by long, flexible rays attached to basal, bony elements)
• Lobe-finned fish (fleshy, muscular pectoral and pelvic fins supported by bony elements)

Question 20

Three surviving lineages of clade lobe-fins

Answer 20

coelacanths, lungfishes, and tetrapods

Question 21

shared, derived trait of clade lobe-fins

Answer 21

Lobed fins

Question 22

Some skeletal elements of lobed fins are homologous to bones in _____ limbs

Answer 22

tetrapod limbs

Question 23

Lungfish

Answer 23

• Two modes of gas exchange: gills and lungs

- restricted to freshwater habitats in the southern hemisphere

Question 24

Lungs of lungfish are homologous to the lungs

of ______

Answer 24

tetrapods