Classification and External Anatomy

Question 1

Phylogeny

Answer 1

The evolutionary development and history of a species or higher taxonomic grouping or organisms.

Question 2

Lineage

Answer 2

A sequence of species each of which is considered to have evolved from its predecessor

Question 3

Traits or characters

Answer 3

A distinguishing quality for a species or group

Question 4

Apomorphies

Answer 4

Derived characters or traits

Question 5

Plesiomorphies

Answer 5

Ancestral characters

Question 6

Synapomorphies

Answer 6

Shared derived characters

Question 7

Symplesiomorphies

Answer 7

shared ancestral characters

Question 8

Autapomorphies

Answer 8

Specialized characters that exist in only one group and are therefore useful for defining that group

Question 9

Node

Answer 9

A point of divergence; a common ancestor

Question 10

Clade

Answer 10

A group without rank

Question 11

Sister groups

Answer 11

Most closely related to each other

Question 12

Dorsal

Answer 12

Back/topside

Question 13

Ventral

Answer 13

Belly/underside

Question 14

Frontal

Answer 14

front/face

Question 15

Caudal

Answer 15

back/tail

Question 16

Medial

Answer 16

middle

Question 17

Lateral

Answer 17

side

Question 18

Spines

Answer 18

stiff and sharp

Question 19

Rays

Answer 19

soft, often branching, and segmented

Question 20

Ceratotrichia

Answer 20

Stiff protein elements that support fins in cartilaginous fishes (Chondrichthyes)

Question 21

Paired fins

Answer 21

pectoral and pelvic

Question 22

Unpaired or median fins

Answer 22

dorsal, caudal, and anal

Question 23

Caudal fins

Answer 23

create forward motion/thrust

Question 24

Protocercal

Answer 24

primitive, extends around the posterior end (lancelets)

Question 25

Leptocercal

Answer 25

Dorsal and anal rays joined with caudal around posterior of fish; vertebra extend fully into tail (coelacanth)

Question 26

Heterocercal

Answer 26

unequal lobed, asymmetrical; vertebral column extends into the upper lobe (most sharks, sturgeons)

Question 27

Homocercal

Answer 27

equal lobes, symmetrical (most bony fishes)

Question 28

4 Homocercal caudal fin types

Answer 28

Round, Truncate, Forked, Lunate

Question 29

Gephyrocercal

Answer 29

“bridge tail”. Dorsal and anal fins have grown around posterior end of fish (Mola)

Question 30

Anal fin

Answer 30

help the fish go up and down, help with stabilization

Question 31

Pelvic fins

Answer 31

Paired; for steering

Question 32

Abdominal pelvic fins

Answer 32

Much farther back on the body; in ancestral fishes

Question 33

Thoracic pelvic fins

Answer 33

Under the pectoral fin; derived fishes

Question 34

Jugular pelvic fins

Answer 34

Under the operculum; derived fishes

Question 35

Pectoral fins

Answer 35

Provide lift, used for maneuvering in tight spaces (like a coral reef)

Question 36

Dorsal fins

Answer 36

stabilize against rolling, assist in turns; may have spines, rays, or both

Question 37

Sagittiform

Answer 37

arrow-like, fast-start lie-in-wait predators (pikes, gars, barracuda)

Question 38

Taeniform

Answer 38

Ribbon-like fishes (gunnels)

Question 39

Anguilliform

Answer 39

Snake-like, good for hiding on holes (eels and lampreys)

Question 40

Filiform

Answer 40

filamentous

Question 41

Depressiform

Answer 41

dorso-ventrally flattened fishes (flounder, skates, rays)

Question 42

Compressiform

Answer 42

laterally flattened fishes (bass, sunfish, butterfly fishes)

Question 43

Fusiform

Answer 43

pointy on both ends; fast fish, pursuit predators (tuna, mako sharks)

Question 44

Globiform

Answer 44

globe-like (porcupine, puffer fish)

Question 45

Canines

Answer 45

grasping

Question 46

Molars

Answer 46

crushing

Question 47

Incisors

Answer 47

chiseling

Question 48

Pharyngeal (“throat”) teeth

Answer 48

good for prey handling in fish that swallow prey whole

Question 49

Triangular cutting teeth

Answer 49

cutting, tearing

Question 50

Taxonomy

Answer 50

The branch of science concerned with classification, especially of organisms