External anatomy

Question 1

What does the body of a fish tell us?

Answer 1

• the natural environment of the fish
• tall narrow fish = live in slow-moving water
• Torpedo shaped = adapted for living in fastermoving water
• bottom dwelling fish have a flattened underside and they stay at the bottom

Question 2

What does the mouth tell us?

Answer 2

• feeding habits
  Top swimmers - Superior mouth (upturnedscoup like mouth)
  Mid water - Terminal Mouth (mouth is at the very tip of their snouts)
  Bottom dwellers - Inferior mouth (underslung mouth so easier to absorb food)

Question 3

What do they use their teeth for?

Answer 3

• holding prey
• help to grind food before swallowing

Question 4

What sort of vision do fish have

Answer 4

Monocular vision (eyes on side of head so cant see directly in front of them)

Question 5

What sort of eyes do deep-water fish have?

Answer 5

large eyes, whoch allows them to absorb as much light as possible

Question 6

What sort of eyes do shallow-water fish have?

Answer 6

have smaller eyes

Question 7

.What are the nostrils for?

Answer 7

• they dont use them to breathe
• water passes through the nostrils
• chemical traces are detected by sensory cells at the base of the nostrils
• Essentisl in low visibility

Question 8

What does the skin do?

Answer 8

• Defend against pathogens
• Skin is covered in mucous layer; this layer will entrap and immobilise small pathogens such as bacteria

Question 9

What do the scales do?

Answer 9

• Made of bony matrial to protect the body
• Point backwards

Question 10

What are the 4 types of scales:

Answer 10

• Placoid scales = Rays, sharks
• Ganoid scales = seen on sturgeons and gars
• Ctenoid scales = perch fish have these
• Cycloid = are round and oval shaped. Trout fish have these.
  Scutes - overlapping bony plates - armoured catfish have them

Question 11

what are the function of fins

Answer 11

• stability
• propulsion
• steering
• balance
• prevent fish from rolling on side
• nose bein gup or down

Question 12

What are the types of fins:

Answer 12

• Dorsal fin (Along the back of the fish between the tail fin and the head)
• Caudal (aka tail) fin
• Anal Fin (underside of body between the pelvic and caudal fin
• Pectoral fin ( beneath the gill opening
• Pelvic fin (in front of anal fin on the abdomen)
  Other fins
• Adipose fin (between dorsal and caudal on tetras)
• Ventral fin - Catfish use them to hold eggs during spawning

Question 13

what does the dorsal fin do?

Answer 13

provides stability so fish can swim in straight line

Question 14

what does the caudal (tail) fin do?

Answer 14

Responsible for propulsions, sudden movements forward and very fast swimming
Can be used to turn and to slow down

Question 15

What does the anal fin do?

Answer 15

Helps with stability and prevents from rolling over

Question 16

WHat does the pectoral fin do?

Answer 16

Used in anvigation ans stsbility
Provide upward lift

Question 17

What do pelvic fins do?

Answer 17

• sued for braking stabilising their bodies and changing directions

Question 18

Lateral line

Answer 18

• Sixth sense
• helps to detect vibrations and current underwater
• senses water movement, pressure and currents
• ## sense vibrations and their direction