fish

Question 1

why do we need to know about fish?

Answer 1

EVOLUTION

• eg. pharyngeal arches
• mammal embryo appears fish like

PUBLIC HEATH

• fish farms
• domestic + international trade

PETS

Question 2

what are fish eggs called

Answer 2

roe

Question 3

describe fish GI tract

Answer 3

no neck/ diaphragm 
>> wide pharynx + short oesophagus 
- conserved GI tract
- J shaped stomach (pyloric caeca aids digestion)
- straight intestine
- long kidney

Question 4

fish heart position

Answer 4

more cranial than mammals

Question 5

where is the swim bladder

Answer 5

dorsal to GI tract and kidney

Question 6

gill structure

Answer 6

• sheets of gills/ gill bars in gill arch
  > Cd edge is respiratory
  > leading edge contains rakers to catch debris + stop gill filaments getting damaged
• lamella protrude from each gill filament = ^ SA
• single afferent artery over gill filament&raquo_space; exchange blood to paired efferent artery (now oxygenated)

Question 7

what are bony fish

Answer 7

Osteichthyes

mostly:
ray fins = teleost + lobe-finned