Lab Glossary of Terms

Question 1

adipose fin

Answer 1

a small, fleshy, rayless structure situated on the midline of the back behind the dorsal fin

Question 2

air bladder

Answer 2

a gas filled sac lying above the semester

Question 3

anal fin

Answer 3

the single fin situated on the midline of the lower body surface behind the anus

Question 4

barbel

Answer 4

a fleshy, flap-like or cylindrical and tapering projection found near the mouth

Question 5

belly

Answer 5

the undersurface of the body from a point immediately behind the pectoral fins to the front of the anal fin

Question 6

body cavity

Answer 6

the space containing the intestine and associated internal organs

Question 7

caudal peduncle

Answer 7

the part of the body between the base of the anal fin and the base of the tail fin

Question 8

concave

Answer 8

curved or rounded inward

Question 9

convex

Answer 9

curved or rounded outward

Question 10

ctenoid scales

Answer 10

scales having a patch of small prickles on the exposed rear part

Question 11

cycloid scales

Answer 11

more or less rounded scales without prickles

Question 11

dorsal fin

Answer 11

a fin (or fins) situated on the midline of the back and having spines or rays

Question 12

ear flap

Answer 12

• a flattened, flexible structure extending back from the rear margin of the gill cover
• best developed in sunfishes

Question 13

eye diameter

Answer 13

the greatest distance from one fleshy rim of the eye socket to the other

Question 14

fin ray

Answer 14

a slender rod-shaped structure supporting the fin membranes

Question 15

soft rays

Answer 15

jointed (crossed by grooves or striations), often branched, and flexible near their tips

Question 16

true spines

Answer 16

unjointed (not marked by grooves or striations), unbranched, and usually sharp and stiff all the way to their tips

Question 17

sculpin spines

Answer 17

soft and flexible

Question 18

gill arches

Answer 18

the series of curved, bony structures lying beneath the gill cover and supporting the gill rakers and gill filaments

Question 19

gill cover

Answer 19

the large, flat bone of the side of the head, beneath which the gills are located

Question 20

gill rakers

Answer 20

the knob-like or comb-like projections on the front edge of the gill arch

Question 21

gill opening

Answer 21

in higher fishes, the single slit-like opening between the gill cover and side of the head

Question 22

occiput

Answer 22

point where the head joins the back

Question 23

lateral line

Answer 23

a series of sensory tubes and pores the extends back from the head along the side of the body

Question 24

complete lateral line

Answer 24

extending to the base of the tail fin

Question 25

incomplete lateral line

Answer 25

terminating before reaching the base of the tail fin

Question 25

lateral line scales

Answer 25

the scales bearing the tubes of the lateral lines

Question 25

lateral line scale count

Answer 25

• begins with the first lateral line scale behind the head and extends back along the lateral line to the hidden base of th etail fin
• scales behind are not counted, scales over crease are counted

Question 25

ray fin count

Answer 25

• only principal soft rays are counted
• all spines are counted, regardless of size

Question 26

myomeres (muscle bands)

Answer 26

• in lampreys, a series of ridge-like bulges of muscles situated along the side
• each muscle band is separated from adjacent bands by definite grooves

Question 27

paired fins

Answer 27

the pectoral and pelvic fins, occupying approximately the same position in fishes as the fore-limbs and hind-limbs of higher animals

Question 28

pectoral fin

Answer 28

the farthest forward or uppermost of paired fins

Question 29

pelvic fin

Answer 29

the paired fun situated beneath or behind the pectoral fin

Question 30

pharyngeal arches

Answer 30

the pair of curved bones located in the throat just behind the last pair of gill arches and bearing the throat teeth

Question 31

scales above the lateral line

Answer 31

• this count begins with the scale at the front of the dorsal fin
• includes all scales in an oblique series downward and backward to the lateral-line scale

Question 32

snout

Answer 32

the part of the head in front of the eye

Question 33

snout length

Answer 33

the distance from the most forward point on the head to the front of the bony socket of the eye

Question 34

soft dorsal

Answer 34

a dorsal fin containing only soft rays or the soft-rayed part of the dorsal fin if both spines and soft rays are present

Question 35

spinous dorsal

Answer 35

a dorsal fin containing only spines, or the forward spiny part of the dorsal fin if both spines and soft rays are present

Question 36

standard length

Answer 36

the straight line distance from the most forward point on the head to the hidden base of the tail fin

Question 37

throat (pharyngeal) teeth

Answer 37

teeth borne in the two curved bones comprising the left and right pharyngeal arches

Question 38

total length

Answer 38

the straight-line distance from the most forward point on the head to the ed of the tail fin, when the mouth is closed anf the lobes of the tail fin are squeezed together

Question 39

heterocercal tail

Answer 39

a caudal fin composed of two asymmetrical lobes

Question 40

homocercal tail

Answer 40

a caudal fin composed of two symmetrical lobes