Fish Lab Exam

Question 1

Function of fins

a) Caudle
b) Anal
c) Pelvic
d) Pectoral
e) Dorsal

Answer 1

a) Caudle: Thrust to project fish through water
b) Anal: Prevent roll
c) Pelvic: Prevent pitch
d) Pectoral: Prevent pitch and yaw
e) Dorsal: Prevent roll

Question 2

Heterocercal

Answer 2

Caudle fin with top lobe longer than bottom (ex. sharks and sturgeon)
Hetero: not the same

Question 3

Homocercal

Answer 3

Caudle fin with both lobes being the same length (ex. trout and bass
Homo: the same

Question 4

Diphycercal

Answer 4

Spear shaped caudle fin (ex. eel)

Question 5

Lunate

Answer 5

Crescent moon shaped tail (ex. tuna)

Question 6

Fusiform

Answer 6

Fish with bullet shape (ex. tuna), made for speed, open water fishes, circular cross section

Question 7

Compressed

Answer 7

Fish with flattened shape from side to side (ex. tropical fish)
Large eyes, do not always move, but move very fast when need be

Question 8

Depressed

Answer 8

Fish with flattened shape from top to bottom (ex. flounder)

Bottom dwellers

Question 9

Eel-like

Answer 9

Circular cross section, lack pelvic fins

Question 10

Ribbon-like

Answer 10

Compressed laterally (ex. prickleback)

Question 11

Arrow-like

Answer 11

Long fragile beak, arrow like body (ex. pike, needlefish)

Question 12

Lower jaw

Answer 12

Lingual teeth (tongue)
Mandibular (mandible)
Basibranchial (center)
Gill arches

Question 13

Upper jaw

Answer 13

Premaxillary (in front of maxillary)
Maxillary (after premaxillary)
Vomer head (center bone, tip)
Vomer (center bone attached to head)
Palatine (diagonally branch off vomer bone)

Question 14

Ganoid scales

Answer 14

Small blocks (ex. sturgeon)

Question 15

Placoid scales

Answer 15

Pointed “triangles” (ex. sharks)

Question 16

Cycloid scales

Answer 16

Most rounded (ex. salmon)

Question 17

Ctenoid scales

Answer 17

Rounded squares (ex. bass)

Question 18

Swim bladder

Answer 18

Maintain position in water column (buoyancy)

Sound reception and generation

Question 19

Lateral line

Answer 19

Sensory organ

• avoid collision,
• orientate themselves in water column with currents
• predation

Question 20

Lateral line neuromast parts, top to bottom

Answer 20

Capula, sensory hairs, sensory cells, nerve

Question 21

Heart parts, bottom to top

Answer 21

Sinus venosus, atrium, ventricle, bulbus arteriosus

Heart is a single loop circulation; heart->gills->body->gills

Question 22

Efficiencies of gills (5 points)

Answer 22

1. Large surface area for gas exchange
2. Short travel distance for oxygen, resulting in increased rate of oxygen entering bloodstream
3. Counter current circulation in gills
4. Little physiological deadspace
5. Continuous flow of water over gills in one direction. Does not energy!

Question 23

Stomach functions

Answer 23

• Produces hydrochloric acid for breakdown of food
• Produces enzyme pepsin
• Pyloric ceca at end of stomach allows for food to enter duodenum

Question 24

Intestine parts and functions

Answer 24

Duodenum: main area for absorption of nutrients
Small intestine: More absorption
Large intestine: Absorption and produces waste materials for excretion

Question 25

Herbivores digestive tract

Answer 25

Long and wiggly as plant material is harder to digest

Question 26

Carnivores digestive tract

Answer 26

Shorter as animal tissue is much easier to digest

Question 27

Sharks digestive tract

Answer 27

Spiral valve for extremely short and efficient digestive tract

Question 28

Liver

Answer 28

Emulsifies fats, detoxifies

Question 29

Gall bladder

Answer 29

Stores bile, produces bilirubin and biliverdin

Question 30

Bile

Answer 30

Emulsifies fats | Acts as pH balancer

Question 31

Spleen

Answer 31

Makes new red blood cells | Destroys old red blood cells

Question 32

Kidney

Answer 32

Removes wastes and water

Question 33

Eyes

Answer 33

Nictitating membrane which acts as an eyelid | Refractive index changes from outside to inside the fishes eye

Question 34

Total length

Answer 34

Tip of nose to tip of tail

Question 35

Fork length

Answer 35

Tip of nose to fork in tail

Question 36

Standard length

Answer 36

Tip of nose to hypural plate

Question 37

Post orbital hypural length POHL

Answer 37

Behind eye to hypural plate

Question 38

Girth

Answer 38

Area of largest diameter

Question 39

Head length

Answer 39

Tip of nose to gill end of plate

Question 40

Snout length

Answer 40

Diagonal line, snout to eyeball

Question 41

Jaw length

Answer 41

Diagonal line, bottom tip to the end of the mandible

Question 42

Internal ear structures

Answer 42

Pars superior: - Semicircular canals - Utriculus and lapillus within structure Pars inferior: - Lagena and astericus within (small structure) - Saccules and Sagitta within (large structure)

Question 43

Types of mouths

Answer 43

Supraterminal: orientated upwards - underbite (freshwater hatchetfishes) Terminal: middle of head, pointed forward (salmon, cod, trout, bluefishes) Subterminal: mouth turned downwards (suckers)

Question 44

Caniiform teeth

Answer 44

Sharp and pointed teeth, like dogs (salmon)

Question 45

Cardiiform teeth

Answer 45

Small velcro like bristly teeth (

Question 46

Pharyngeal teeth

Answer 46

Teeth at the back of the throat (suckers)

Question 47

Fused incisors or molars

Answer 47

For crushing and grinding

Question 48

How many fish species are on Earth?

Answer 48

24,600

Question 49

What is a species and who came up with this definition?

Answer 49

Groups of interbreeding natural populations that are isolated from other such groups. Ernst Mayr 1996