Fish

Question 1

What class are fish in?

Answer 1

Actinopterygii

Question 2

How many species?

Answer 2

Approximately 40,000 (about 1/2 of all vertebrate species)

Question 3

What kind of tail do fish have?

Answer 3

Homocercal

Question 4

What type of scales to fish have?

Answer 4

Usually Ctenoid (D-shaped, rougher surface) or Cycloid (round/smoother)

Can also be ganoid, cosmoid, or scutes

Question 5

Osmoregulation in fish (fresh vs. salt water)

Answer 5

Saltwater: drinks seawater, salts excreted through gills and gut. Produce small volume of relatively salty urine. Water loss by osmosis through gills and skin.

Freshwater: does not drink, salts absorbed by gills, no salts enter gut. Produce large volume of dilute urine. Water gain by osmosis through gills and skin.

Question 6

Osmoregulation in sharks vs. fish

Answer 6

Sharks: gills block loss of urea, ingests salts with foods. Most urea retained by kidneys, salts excreted in urine & by rectal gland. Slight water gain by osmosis through gills and skin.

Bony fishes (marine): gains water and salts by swallowing seawater and food. Salts excreted by chloride cells of gills, some salts pass through gut, some salts & water lost via urine. Kidneys retain water. Water loss by osmosis through gills and skin.

Question 7

Unpaired fins

Answer 7

2 dorsal fins, caudal fin, anal fin

Question 8

Paired fins

Answer 8

Pectoral fins and pelvic fins

Question 9

Spiny dorsal

Answer 9

1st dorsal fin. Primarily for maneuvering, stabilization & defense.

Question 10

Soft dorsal

Answer 10

2nd dorsal fin. Primarily for low speed maneuvering and swimming.

Question 11

Caudal fin

Answer 11

Tail fin. Used for propulsion.

Question 12

Anal fin

Answer 12

On ventral (bottom) side, toward back, opposite of soft dorsal. Used for stabilization.

Question 13

Pectoral fins

Answer 13

Located on sides of body. Used for swimming, maneuvering, and stabilization.

Question 14

Pelvic fins

Answer 14

On ventral side underneath the pectoral fins, used for stabilization.

Question 15

Operculum

Answer 15

Gill cover, bony and tough structure

Protects gills and serves as “bellows” to help pump water over gills

Question 16

Branchiostegal Membrane

Answer 16

Seals operculum and prevents back flow of water into the gill chamber

Question 17

Nares

Answer 17

external nostrils, used in odor detection (not breathing)

Question 18

Lateral line

Answer 18

Series of small fluid-filled canals lying just beneath the skin on the head and along the sides of the body (dark colored). System of receptors transforms underwater sound or mechanical disturbance into nerve impulses.

Question 19

Caudal peduncle

Answer 19

located just before the caudal fin

Function: generates power to the caudal fin for swimming

Question 20

Stomach

Answer 20

located in middle of body cavity, comes after esophagus and before intestines

function: food storage and digestion

Question 21

Pyloric caeca

Answer 21

finger-like structure located above/underneath the stomach

function: aid in digestion and absorption

Question 22

Gall bladder

Answer 22

small, located toward front of body (between stomach/liver)

sac, typically green, that holds bile for enzymatic digestion

Question 23

Intestine

Answer 23

located after stomach, large, twisty

simple intestines, used for digestion

Question 24

Pancreas

Answer 24

a diffuse organ, extending over the surface of the intestine and connective tissues/blood vessels. Can only be differentiated by using a microscope.

function: secretion of digestive juices and insulin

Question 25

Liver

Answer 25

under the stomach towards the front of body. dark in color.

bile secretion, glycogen and vitamin D storage

Question 26

Heart

Answer 26

small, dark colored, hides under the gills

2 chambers: atrium and ventricle

Question 27

Gill rakers

Answer 27

teeth-like, toward head

strains water and retains food

Question 28

Gill arches

Answer 28

bone-like, between rakers and lamellae

supports the gills

Question 29

Gill lamellae

Answer 29

back end of gills

feather-like portion of the gills, responsible for gas exchange

Question 30

Kidneys

Answer 30

thin, dark skinny structure above the swim bladder

function: elimination of waste and regulation of internal environment

Question 31

Gonads

Answer 31

Female: ovaries, for egg and hormone production.

Males: testes, for sperm production

Located under swim bladder & above digestive system

Question 32

Cloaca/anus/vent

Answer 32

common chamber for receiving the openings of the urinary tract, oviduct (females) or vas deferens (male) and the intestine

Located right in front of Anal fin

Question 33

Swim bladder

Answer 33

large, light colored organ located in the middle of the body cavity just under the spine

function: buoyancy, hydrostatic balancing & sound production

Question 34

Myomeres

Answer 34

bundles of skeletal muscle