1
Q
what’s an example of Agnatha?
A
hagfish
lampreys
2
Q
what’s an example of Chondrichthyes?
A
sharks
3
Q
what’s an example of Osteichthyes?
A
teleosts
4
Q
what is agnatha?
A
jawless fishes
5
Q
what are chondrichthyes?
A
cartilaginous fishes
- sharks
- skates
- rays
- chimeras
6
Q
describe Chondrichthyes
A
- cartilaginous skeleton
- replaceable tooth rows
- dermal skeleton
7
Q
describe osteichthyes
A
- bony fishes
- true bony skeleton
- more diverse than Chondrichthyes
- teeth fixed in jaws
8
Q
describe lampreys
A
freshwater
eel-like
parasites
9
Q
describe hagfish
A
- marine
- eel-like
- scavengers
- eat dead animals and worms and snails
- tie self into a knot and move forwards
- rough skin - absorb nutrients through skin
- secrete immense amount of slime for defense = slime eels
10
Q
why do hagfish have rough skin?
A
allows for extra nutrients to get absorbed because scavenging can only provide so much nutrients
11
Q
what are the kinds of fishes?
A
- rover
- surface oriented
- bottom fish
- deep bodied
- eel like
12
Q
whats an example of surface oriented fish?
A
flying fish
13
Q
whats an example of a bottom fish?
A
small fish, snails and crabs
-> dorsoventrally flattened
14
Q
whats an example of a deep bodied fish?
A
herbivores or coral specialists
-> specialized bottom feeders
15
what is form a combination of?
A
- acceleration -> maximized by repulsion
- cruising -> continued undulation -> stiff bodies
- maneuvering -> deep bodied fish. sudden changes in movement
16
Q
poikilotherms
A
- most fish are cold blooded but some are endothermic to allow for hunting in cold waters
-> tuna and swordfishes
17
Q
what is an example of a cruising specialist?
A
tuna - predator
18
Q
what is an example of maneuvering specialist?
A
butterfly fish - coral and herbivore
19
Q
what is an example of an acceleration specialist?
A
barracuda - predator
20
Q
what does swimming involve?
A
undulation of entire body
21
Q
how does a shark move?
A
thrusts depending on the shape of the tail
22
Q
what are the components of force during swimming?
A
propulsive element
side force
thrust
normal force
23
Q
mola mola
A
- three species
- pufferfish
- slow moving
- deep diving
- feed on jellyfish
24
Q
compare sharks and bony fish
A
sharks have cartilage making them light
bony fish have mineral skeletons making them heavier
25
Q
how do sharks control buoyancy?
A
fat storage in liver
26
Q
how do bony fish stay neutrally buoyant?
A
regulate bulk chemistry
27
Q
are bones and tissues denser than water?
A
yes
28
Q
what is the purpose of swim bladder?
A
in bony fishes so gas is exchanged by a network of capillaries called the rete mirabile
29
Q
rete mirabile
A
exchange of gas in from blood into swim bladder
- oxygen is exchanged into swim bladder and O2 leaves and goes into bladder
30
Q
oxygen use in fish
A
oxygen exchange
- water flows over gill lamellae and oxygen diffuses into gills
31
Q
what is countercurrent exchange?
A
blood flow is in opposite direction of water flow
- blood flow picks O2 which is opposite to water
32
Q
solute exchange in sharks
A
isotonic
- blood osmolarity almost the same as seawater
- sharks do not need to drink water
- solute excretion via rectal gland
-> same solute concentration as water
33
Q
solute exchange in bony fish
A
hypotonic
- blood has fewer solutes than sw
- drink a lot of water and excrete solutes
- solute excretion over gills (via chloride cells)
34
Q
can sharks live in freshwater?
A
yes for extended periods as they retain the salt from the ocean and recycle it in the body
35
Q
bull sharks
A
- conserve urea
- absorb salts
- juveniles found high in estuaries -> maintain internal salinity and can be found very high up in fresher water
36
Q
dogfish
A
- unable to survive long-term fresher than 50/50
- known to enter estuaries
- cannot live higher up in estuaries
37
Q
how do predatory sharks feed?
A
teeth produced by tooth bed but temporary
- dentine but no root
- drop one a week minimum
- teeth in skin -> placoids, provide protection but light weight
38
Q
basking sharks
A
- larger filter
- gill rakers -> bars on gills with filaments that collect tiny particles
- temperate water distribution
- feed on copepods, shrimp and fish eggs
- passively consume water and captures the floaty bits
39
Q
whale sharks
A
- filter plankton using gill rakers
- long life span
- ovoviviparous -> birth to live young hatched from eggs inside female
- largest known extant fish
- exchanged
- huge migratory areas
- overlap with tuna
- hunted for fins illegally
40
Q
oviparous
A
lay egg cases
- sharks and rays
41
Q
viviparous
A
placental
- birth to live young
- bull shark
42
Q
ovviparous
A
produce eggs which hatch inside female
- birth to live young
- dogfish
- whale shark
43
Q
sensory systems
A
- hearing
- lateral line systems
- ampullae of Lorenzini
- smell
- eyesight
44
Q
describe the hearing system
A
ears behind eyes
- hair cells very sensitive to low frequency sounds and have good directional hearing
45
Q
describe lateral line system
A
hair cells in fluid-filled canals down head and trunk - detect water vibrations
- separate nerve endings
46
Q
ampullae of lorenzini
A
small pores filled with glycoproteins detect electrical fields
47
Q
smell
A
excellent smell through nares
48
Q
eyesight
A
color vision and see well in low intensity with two specialized features
49
Q
what is used for low light in eyesight?
A
tapetum lucidum
50
Q
what is tapetum lucidum?
A
reflective surface behind the retina boosts the visual signal in low light levels
51
Q
what is nictating membrane?
A
cover over the eye to protect it from damage when feeding
52
Q
what are the 7 species of sea turtles?
A
- loggerhead (most common)
- green (two subspecies possible)
- hawksbill
- kemp ridleys and olive ridleys
- flatback
- leatherback
53
Q
describe leatherback turtles
A
- adaptions for anaerobic respiration during long dives
- small lung
- sphincter that shuts lungs off
- leatherback has compressible shell
- increased blood vol and increased concentration of myoglobin
- largest
- fastest -> high Re
- longest migrations
- single member of group with bony skin
- feed mainly on jellyfish
-»»> critically endangered
54
Q
ridleys’ turtle
A
mass egg laying events “arribadas”
- only sea turtle that does synchronous egg laying
55
Q
loggerhead
A
- massive head
- strong jaw for eating molluscs
- keystone species for role in moving nutrients on reef
- large number of eggs per nest
- eats shells and leaves calcium out for the ocean floor
56
Q
describe the life history of turtles
A
- maturity is 11-40 years
- females return to land to lay eggs
- lay up to 100+ eggs/nest
- incubation time is approx 2 months
- young turtles fed upon by birds and fish
- eggs dug up for food by people
- temp dependent sex determination
57
Q
how does temp affect sex determination?
A
climate change means the globe is warming up meaning that there are more F than M
- females incubate above 31C
- males incubate below 27C
58
Q
A
