fishes

Question 1

What are some distinguishing characteristics of vertebrates?

Answer 1

vertebral column, brain encased in skull, closed circulatory system, various internal organs

Question 2

What class do lampreys belong to?

Answer 2

petromyzontida

Question 3

What are some unique characteristics that differentiate lampreys from other fish?

Answer 3

lack scales, jaws, and paired fins

Question 4

How are adult lampreys different from their larval form?

Answer 4

adult lampreys are parasitic (using a buccal funnel covered in papillae) while larval lamprey are filter feeders

Question 5

Do lamprey possess lateral lines? If so, what is its function?

Answer 5

yes, it is used to detect vibrations and currents

Question 6

What is the function of the oral glands in lamprey?

Answer 6

they secrete an anticoagulating agent that prevents host’s blood from clotting and promoting blood flow

Question 7

How many chambers does the lamprey (and all fish) heart have?

Answer 7

two chambers (one atrium and one ventricle)

Question 8

What are the defining characteristics of the class chondrichthyes?

Answer 8

cartilaginous skeleton, paired fins, and jaws

Question 9

What class do sharks, skates, and rays belong to?

Answer 9

chondrichthyes

Question 10

Do sharks have lateral lines? If so, what is their function?

Answer 10

yes, like the lampreys it serves to detect movements, vibrations and currents

Question 11

Where are the spiracles located on a shark, and what is their function?

Answer 11

they are located right behind the eyes and they provide a second entrance for the water so more oxygen can pass over their gills

Question 12

What is unique about the liver of sharks?

Answer 12

it is filled with oil (squalene) that allows them to maintain buoyancy

Question 13

What is the function of the rectal gland in sharks?

Answer 13

excrete excess salt for osmoregulation

Question 14

Where are the rugae found in sharks, and what is their function?

Answer 14

they are found in the interior of the stomach, allowing it to expand

Question 15

What is the function of the spiral valve in sharks?

Answer 15

to slow the passage of food and increase the surface area of the intestine to aid in digestion

Question 16

What are the type of scales that are found on cartilaginous fishes called?

Answer 16

placoid scales (dermal denticles)

Question 17

What are the characteristics of placoid scales?

Answer 17

stacked and have spiny toothlike projections. when stroking a shark from the head to the caudal fin, it feels smooth, but when stroked in the opposite direction it feels like sandpaper due to the spiny toothlike projections. the flattening in the forward direction helps reduce drag and make swimming more efficient.

Question 18

How can you determine if a shark is male?

Answer 18

a male shark will have two claspers for depositing sperm into the female’s cloaca. internally male sharks will have two testes, although one is typically greatly reduced.

Question 19

Do both male and female sharks possess a cloaca? What is its function?

Answer 19

yes both male and female sharks possess a cloaca. the cloaca is the opening where both the rectum and urogenital ducts empty.

Question 20

How can a female shark be identified?

Answer 20

female sharks will lack claspers, and internally they will have paired ovaries that will contain eggs. in addition, the cloaca in females has urinary, digestive, and reproductive functions.

Question 21

What class do the ray-finned fishes belong to?

Answer 21

actinopterygii

Question 22

What are the defining characteristics of the class actinopterygii?

Answer 22

they possess a bony skeletal system unlike that of chondrichthyes, and their fins are supported by fin rays

Question 23

What is the function of the operculum?

Answer 23

protects the gills and aids in respiration by pumping water over the gills

Question 24

What is the swim bladder and what is its function?

Answer 24

the swim bladder is a gas filled sac used by ray-finned fishes for maintaining buoyancy.

Question 25

What is the function of the gills in ray-finned fishes?

Answer 25

respiration and absorption of salt from surrounding water

Question 26

How can you tell if a perch is female?

Answer 26

females will only have one ovary that produces eggs (but will have one that isnt functional as well)

Question 27

How can you tell if a perch is male?

Answer 27

the male will have two testes that produce sperm

Question 28

What are the characteristics of ctenoid scales?

Answer 28

ctenoid scales are comb-like teeth scales that are found in many ray-finned fishes, such as perch. the overlapping of these scales is what allows perch to be more flexible.

Question 29

What is the function of the pectoral and pelvic fins?

Answer 29

maneuverability

Question 30

What is the function of the dorsal and anal fins?

Answer 30

stability

Question 31

What is the function of the caudal fin?

Answer 31

propulsion and power for swimming

Question 32

What class do hagfish belong to?

Answer 32

myxini

Question 33

What are some characteristics of the class myxini?

Answer 33

they lack the distinctive funnel shaped mouth found in lampreys, and instead have a mouth surrounded by 4 pairs of sensory tentacles. inside the mouth are tooth plates made of keratin to rasp away the flesh of dead organisms. they lack vertebrae and retain the notochord until adulthood (they are still part of subphylum vertebrata though). possess glands in the side of their bodies to secrete copious amounts of slime for defense.