Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Vertebrate Biology > Elasmobranch Diversity And Adaptions > Flashcards

Elasmobranch Diversity And Adaptions Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Basic characteristics of Chondrichthyes

A 
Jawed
Paired fins
Scales (denticles)
Cartilage skeleton
Gills
No gas bladder
Fertilisation is internal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are elasmobranchs?

A

Skates rays (batoids) and sharks

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

What is the body form of batoids?

A

Flat bodied, with pectoral fins developed into broad flat wing-like appendages

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

What is the major difference between skates and rays?

A

Rays are viviparous (live baring)

Skates are oviparous (egg laying)

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

What are dorsal fins like in skates and rays?

A

Skates have prominent dorsal fins

Rays have absent or reduced dorsal fins

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

What are the pelagic zones

A
  • epipelagic: surface to 200m
  • mesopelagic: 200-1000m
  • bathypelagic: 1000-4000m
  • abyssopelagic: 4000-sea floor
  • hadopelagic: ocean trenches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do skates reproduce?

A

Male use claspers to direct flow of semen into females cloaca

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

What shape ratio do sharks have?

A

3-8, ideal is 4.5 fusiform

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

What are shark fins used for?

A

Stabilising, steering, lift, propulsion

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

What are the possible uses of dorsal fins

A

They have 1 or 2, antiroll stabilising fins, or possibly spiny for defence like dogfish

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

What are pelvic fins used for

A

Stabilisation

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

What are pectoral fins used for

A

Steering and lift

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

What is a heterocercal tail

A

Where the vertebrae extend into a large lobe, so tail is asymmetrical

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

What is a homocercal tail

A

Where the vertebrae do not extend into a lobe, so tail is more or less symmetrical

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

What are the small rough scales on sharks called and what are they

A

Dermal denticles, bony plate buried in the skin

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

What are dermal denticles homologous in structure to

A

Teeth

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

What is their function?

A

Form protective barrier and aid swimming by reducing drag

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

Are teeth lodged permanently in the jaw?

A

No

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

What is the membrane called that shark teeth are attached to

A

Tooth bed

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

How is the tooth bed similar to a conveyor belt?

A

Moves rows of teeth forward as the shark grows and replace older teeth in front that have become damaged, lost or worn

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

How is she determined in sharks, and what is the oldest shark found?

A

Counting growth rings on vertebra, Greenland shark 272y

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

What are many species of elasmobranchs threatened by?

A
  • fisheries (mainly for fins), protected in uk since 1999
  • shark nets
  • accidental catch (by catch)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why do sharks need dynamic lift?

A

Because they don’t have gas bladders, more dense than the water so sink

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

How do they create dynamic lift?

A

By using their pectoral fins as lifting foils or inclining their bodies at an angle of attack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the problems for elasmobranchs having to create dynamic lift?

A

Energy expenditure

Always have to be moving to create lift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How do most bony fish create static lift

A

Swimbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do elasmobranchs generate static lift?

A
  • low density building materials (cartilage)
  • lipids/oils
  • store oil in liver and muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How many pair of gills do sharks have?

A

5-7

29
Q

How does water pass over the gills

A

Enters through the mouth (or spiracle) into the pharynx, over the gills and exits through the gill slits, water must always be passing over the gills to oxygenate the blood

30
Q

What is the spiracle

A

Basically a first gill slit behind the eye

31
Q

What is the purpose of the spiracle

A

Provide oxygenated blood directly to the eye and brain

32
Q

Which types of sharks are spiracles more common in?

A

Large, bottom dwelling sharks

33
Q

What is the spiracle used for in rays

A

Rays it is larger and is used to actively pump water over gills while it is buried in sand

34
Q

What are the ampullae of Lorenzini?

A

Small vesicles and pores,
A subcutaneous sensory network
Around the head as dark spots

35
Q

What is each ampullae like?

A

Multiple nerve fibres enclosed in glycoprotein gel with electrical properties

36
Q

What do the ampullae of lorenzini detect?

A

Weak magnetic fields produced by other fishes when muscles contract, allowing them to locate prey
AND
Use them to navigate earths magnetic fields

37
Q

What is the second part of the electrosensory component

A

Lateral line

38
Q

What did the lateral line do?

A

Allows sharks to orientate to particle movement or sound

39
Q

What are the structures called that allow the detection in the lateral line

A

Neuromasts

40
Q

How do sharks hear?

A

Very sharp sense of hearing, hear prey many miles away

Small openings with thin canal to inner ear

41
Q

What is the lateral line and hearing system grouped called?

A

Acoustico-lateralis system

42
Q

Where is the olfactory sense located

A

In short duct between the anterior and posterior nasal openings

43
Q

What small amount of blood can some species detect?

A

1 part per million

44
Q

What smells are sharks attracted to?

A

Chemicals found in guts of many species, and so found near sewage pitfalls

45
Q

What do nurse sharks have to increase their ability to sense prey?

A

Barbels

46
Q

What is the first thought for ‘why the hammer’

A

Hydrodynamic lift

47
Q

What is the second thought for ‘why the hammer’

A

Sensory enhancement

  • have specialised grooves which channel scent bearing water into nostrils
  • ampullae of lorenzini distributed under whole hammer, act as metal prey detector
48
Q

In terms of salt, what is the blood in relation to the sea

A

Isotonic

49
Q

How are they isotonic?

A

High concentration of urea and TMAO, in osmotic balance with seawater

50
Q

What does the fact they are isotonic mean for most sharks?

A

Cannot survive in freshwater

51
Q

What is the exception to not being able to live in freshwater and how does it do it

A

Bull shark

Change kidney function to excrete large amounts of urea

52
Q

What does the Nicaragua Bull shark do to counteract the fact it’s body fluids are twice as salty as freshwater fish

A

Pees a lot of dilute urine

53
Q

Are most sharks ectotherms or endotherms?

A

Ectothermic

54
Q

Give an example of a shark that is an endotherm

A

Shortfin mako shark and great white shark

55
Q

How do endothermic sharks maintain body temperature higher than water?

A

A strip of aerobic muscle located in centre of body generates heat, which is transferred to blood by countercurrent exchange in rete mirabile

56
Q

Are sharks sexually dimorphic?

A

Yes, females have cloaca and males have claspers

57
Q

What is a clasper

A

Rolls of cartilage, with paired testes, right bigger than left

58
Q

What is the cloaca?

A

Opening between the pelvic fins,

Paired ovaries, right bigger, left sometimes don’t produce any eggs

59
Q

How do porbeagle sharks mate?

A
  • sharks meet face to face
  • make inserts one of his claspers into cloaca
  • sperm (within spermatophore) ejected by contracting organs called siphon sacs
60
Q

How can data be gotten from elasmobranchs?

A
  • dead - fossils/bycatch

- tagging, observations etc.

61
Q

Give an example of shark with limited distribution and one with wide range (across oceans)

A

Northern river shark - tidal rivers in N Australia

Great white/basking/salmon

62
Q

What methods can be used to investigate distribution ?

A

ID tags, photo-id, radio satellite tags

63
Q

How can population structure be investigated?

A

Morphometrics - (small differences in skeleton structure between non-interbreeding populations)
Genetics and DNA forensics
Ecological

64
Q

How do sharks life spans vary?

A

Most live 20-30

But some much older such as Greenland shark 272

65
Q

Sharks are k-selected reproducers, what does this mean?

A

Produce a small number of well developed young

66
Q

How does fecundity vary in sharks?

A

From 2 to over 100 per cycle (1-3 years), sharks mature very slowly

67
Q

What percentage of chondrichtyan are considered ‘safe’

A

23%

68
Q

How many sharks are killed per year from commercial and recreational fishing?

A

40-100million

69
Q

What happens to the ecosystem when you remove large scale apex predators?

A
  • lack of prey regulation
  • ecosystem shift
  • possible cascading effects

Vertebrate Biology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions