Sharks Exam 2 Flashcards

(80 cards)

1
Q

What are types of predatory behavior?

A

chasing, hunting by speculation, ambushing, stalking, luring, scavenging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of body makes sharks ideal hunters?

A

Fusiform

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What kind of feeders are sharks?

A

Opportunistic feeders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is speculative hunting?

A

They hunt in area that they assume will have fish or

follow another animal that may lead it to food. This is a learned or innate/genetically programmed behavior.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Example of speculative feeding?

A

Rays position themselves at high tide water movement areas and wait to be flushed out.
Tiger sharks aggregate during june/july during fledging periods of birds, eating the them as they land on the water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is ambushing?

A

Hidden, waits for prey to come to it, then launches at prey as it comes by.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is stalking?

A

Uses stealth and approaches prey.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between stalking and ambushing?

A

Ambushing prey comes to it, where stalking predator goes to prey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What kind of hunting do white sharks do?

A

stalking and speculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is luring and example?

A

Lure prey to eat. Cookiecutter sharks glow or flash and fish are attracted to it. Parasitic shark.
Kite fin and Greenland do similar
White tip shark is believed to attract prey with tips of fins. Hunt in groups one lures fish in until it is surrounded.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

WHat does a tiger shark do?

A

scavenge but not exclusively. dead whales and fish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Do sharks do cooperative or group foraging?

A

possibly, not known if its cooperative or aggregations. Aggregations of shark work together to feed.
Sevengill sharks encircle a seal slowly tightening the circle until one strikes.
Thresher sharks herd fish with tail.
Black tip drive bait on to the beach
Generally eat one at a time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do sharks avoid predation?

A

disruptive coloring, false eye spot, cyrpsis, spines, large body size, electric discharge, crypsis and immobility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is disruptive coloring?

A

morphology-has patterns, bar up/down or stripes head to tail

ex. rays blend in with surrounding to avoid hammerhead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is false eye spot, how does it work?

A

Large round spots generally in a location that is affordable to lose. Other thought is that it startles the fish enough to get away.
Eye is big, makes fish look bigger.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is crypsis?

A

has appendages that look like seaweed or coral. Acts like camo, allow them to hide to catch prey and be hidden.
Can have both crypsis and disruptive coloring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do spines help?

A

Most are poisonous spines. ie Horned shark

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Example of avoiding predation with large body?

A

Whale shark

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is capable of electric discharge?

A

California electric ray and common electric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do crypsis & immobility work?

A

Ray buries itself in the sand and remains still until prey comes by or it detects the electrical signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do sharks behaviorly avoid predation?

A

refuging, display, schooling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are two types of refuging?

A

biotic refuging-gather in a group, hide in numbers, not necessarily school
abiotic refuging-move to shallow water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the apparent looming threshold?

A

the point at which the distance and the size of the object makes one flee.
An advantage to having a long beak, fish focus on the body size and don’t see the beak until it is too late

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do behavioral displays work?

A

drops pectoral fin, then moves up and down in the water column. Confused, attacking and withdrawing, attacks out of fear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Are these proven predation behaviors?
No, none of these have ever been proven
26
How does schooling avoid predation?
Reduced predation due to the confusion affect. Predators cant fixate on one fish when there are many moving. Also diluted affect-the predator cant eat all of the fish.
27
Fish are considered schooling when?
they are polarized and synchronized. increased vigilance.
28
What are types of prey capture?
suction feeding, bite feeding, ram feeding
29
What is pure suction feeding?
predator is stationary and prey is moving or being sucted out ex.bamboo and nurse, spotted eagle ray
30
What is pure ram feeding?
prey is not moving only predator predator moving at high rate, prey is stationary ex. white shark-very little suction
31
What is bite feeding?
prey is not moving predator moving at medium rate, prey is stationary ex.hammerhead shark uses cephalofoil to stun ray then bites
32
What type of mouth do suction feeders have?
round small mouth, laterally occluded by labial cartilage (swings forward making opening), rapid jaw opening ( 35ms to open), enlarged hypertrophied jaw abductor muscle, small teeth, little cranial elevation
33
What type of mouth do ram and biting feeders have?
larger mouth with lateral gape, slower mouth opening, powerful jaw adductor muscles, large cutting teeth, cranial elevation during capture
34
What is the ancestral feeding method?
Suction feeding
35
what is the suction feeding range?
3-5 cm
36
What sharks are generalist feeders?
Dogfish and leopard, suction and ram
37
What are types of filter feeding?
intermittent suction filter feeding - open and clothes mouth ex.megamouth and whale shark continuous ram filter feeding-mouth always open ex.manta ray, basking shark
38
What type of feeding does a megamouth do?
engulfment feeding
39
What type of jaw do sharks, skates and rays have?
Sharks have hyostyly - jaws connected to cranium by hyoid and anterior ligament Skates and rays have euhyostyly-jaws connected to cranium by hyoid only
40
What are the functions of protrusion?
1-shark or ray can pick things off the bottom 2-gouges pieces of prey 3-decreases the time to close the mouth 4-may align the mouth with the prey better 5-allows to reposition the prey or bite
41
What is monognathic heterodonty?
each jaw has one type of teeth
42
What is dignathic heterodonty?
different teeth on one jaw
43
What type of teeth do rays have?
Mouth plates
44
What kind of teeth do indeterminant growth animals have?
polydont teeth, teeth get bigger as animal grows bigger
45
Do biologists use pressure or force for biting?
bite force to penetrate it takes 10-20N Leaning is pressure not force
46
How is bite force related to shark size?
The larger the shark the higher the bite force. ex. Bull shark, TL285 cm, 478lb on front, 1330lb on back Bonnet head, TL 96 on front, 35.4lb on back
47
Where is bite force greatest?
Closest to the hinge
48
How do sharks remove on wanted objects from their stomachs?
They invert it | ex. Mako. Dogfish cannot invert stomach
49
Are intestines the same?
No, four different kinds of folds. Carnivores have short intestines. Herbivores have long
50
Does diet vary among sharks?
yes, Large sharks eat marine mammals | small sharks eat fish
51
What is Ontogenetic dietary switch?
A sharks diet changes as it grows. teeth change as well.
52
How do we analyze stomach contents?
gastric evulsion-types include: stable isotope analyzes (isotopes change with type of food), PVC pipe/hand, flush out stomach however diet is biast to hard stuff, versus soft tissue
53
What is total gastric evacuation time?
varies considerably but longer than bony fish. greater than 50-100 hours
54
Preferred diet of sharks?
S. tiburo - blue crab P. glauca(blue shark)-squid H. francisci(CA horned shark)-urchins White sharks - switch bony to marine with growth
55
How long do sharks feed?
intermittent feeders-not eating machines-opportunistic whale sharks feed 7-8hrs some eat once may not eat again for several days eat 1-3% of body weight per day
56
What time of day do sharks prefer?
Little evidence of increased feeding at dusk or dawn velocity goes up at night many nocturnal ex bonnethead, horned shark and nurse
57
What is the difference between red muscle and white muscle?
Red muscle is for continuous swimming | white muscle is for burst speeds
58
What kind of fish maintain warm muscles?
tuna and lamnid sharks
59
Where is lamnid sharks RM?
It is in the center of the shark, right and left of the vertebrae column.
60
How did the twitch time vary?
RM had 3s long twitch duration - Q10 of 3.7 | WM had 51-143 ms,Q10of 2.
61
What are the stable temp of each muscle?
RM - 26C or higher, low temp long twitch duration slow muscle movement, high temp faster twitch WM - 10-26C, muscle twitch remained constant over change
62
WHat happens if RM cools?
It will cease to contract, fish will sink and die
63
What else does RM warm?
White muscle
64
Endothermy vs ectothermy
internally regulated via red (s) muscle vs environment regulates heat
65
What is rete mirable?
it is a network of countercurrent blood vessels. -the heat is transferred to the blood going the opposite way. the heat is internalized and does not dissipate to the outside muscle contractions generate heat
66
What shark family is endothermic?
lamnidae-mako, salmon, white and parbeagle
67
WHat special features do lamnideas have?
lateral cutaneous rete sometimes an orbital rete-eye suprahepatic rete - anterior to the liner higher metabolic rate
68
What is the temp of Mako, white and salmon?
Mako - 8C White - 14C Salmon - 18C
69
What are the common factors between endothermic tunas and sharks?
- RM is typically medial towards the red line and anterior - elevated body temperatures; rete - myotomes-most elongated - thunniform and homocircal tail - red muscle is separated from the white muscle by loose connective tissue (red contraction is out of phase with the white contraction)
70
Where do tendions run down?
core of myoseptum to tail.
71
WHat do tendions do?
transfer force down to tail
72
WHat order to the RM and WM fire in?
White first, red second = eventually i sequence
73
What is tendions in phase with?
white muscle
74
Why are muscle separate?
so they can fire separately
75
Why do sharks warm their bodies?
move better, swim faster | stay warm as they dive- maintain speed and power
76
What do endothermic sharks have?
large gills, relatively large hearts, greater hemoglobin levels, higher enzyme activity
77
WHat is Q10?
the rate of change for every 10 degrees
78
What muscle has a higher twitch time?
RM overall was greater
79
Who is an obligate endotherm?
lamna ditropis-salmon shark - has to keep swimming to maintain body temperature - if it loses heat to RM it will never regain
80
What is the difference between isometric and isotonic?
Isometric is where the muscle TRIES to contract | Isotonic is where the muscle DOES contract