Lec 8

Question 1

Adaptations to increase Buoyancy

Answer 1

Some vertebrates carry large quantities of oil, fat, and other substance less dense than water

Question 2

Adaptations to decrease buoyancy

Answer 2

some vertebrates have unusually thick and dense bones

Question 3

Adaptations to flexible controls of buoyancy

Answer 3

Some fishes carry swim bladders with adjustable volume of gas

Wall of gas bladders contain guanine crystals, to prevent gas loss

Some derived fishes travel great vertical distances, loss their swim bladder

Question 4

Two types of gas regulation

Answer 4

Physostomus

Physoclistous

Question 5

Physostomus

Answer 5

Gas bladder is connected to the stomach via direct connection

Gulping air at surface to fill gas bladder

Burping air out via jawed mouth

Typically, gas bladder is filled at the surface before descend and released during ascend

Question 6

Physoclistous

Answer 6

Gas bladder is connected to a network of vessels called rete mirabile

Gas gland excretes lactic acid and carbon dioxide to lower pH at contact between rete mirabile and gas bladder

Hemoglobin releases oxygen due to low affinity at low pH

Sphincter of ovale allow gases to enter ovale, and reabsorbed into the blood stream

Question 7

Limitations of gas bladder

Answer 7

Contribute to barotrauma

Question 8

Barotrauma

Answer 8

Drastic changes in pressure lead to expansion of gas bladder

Question 9

Rule of thumb of Dr.Murray

Answer 9

Slow ascend at about 1 metre per hour, though some species can do up to 3 metres per hour

Question 10

Locomotion: The Manus Invisibia

Main fluid dynamic forces in the environment

Answer 10

Weight

Lift (must balance weight)

Drag (forward resistance)

Thrust (must overcome drag)

Question 11

From whence thou drag

Answer 11

The rate of removal of momentum from moving water by an immersed body

Question 12

Drag is approximately proportional to

Answer 12

Density of fluid

Square of the velocity of the fluid

Cross section area of the immersed body

Question 13

Challenges of vertebrates concerning thrust and drag

Answer 13

Thrust producing and drag inducing structures are inseperable

Question 14

Undulation

Answer 14

Pushing backwards and sideways against the water with the tail, or with a travelling wave that moves along the body

Question 15

Backwards pushing creates

Answer 15

Thrust

Question 16

Sideways pushing is cancelled out by

Answer 16

The sweep of the tail or body in the opposite direction

Question 17

Dynamic lift for buoyancy is possible with

Answer 17

Continuous movements, especially with a heterocercal tail

Question 18

Curvature of body is represented as

Answer 18

Waves

Question 19

Level of undulation is represented as

Answer 19

Number of wavelengths

Question 20

Three types of controls

Answer 20

Roll

Yaw

Pitch

Question 21

All but … can be the primary structure of locomotion

Answer 21

Pelvic fins

Question 22

Respiration usually occurs through

Answer 22

Flow through respiration with gills

Question 23

Water flow is generated by muscles of

Flow through respiration with gills

Answer 23

The pharynx in cyclostomes and muscles of the jaw in gnathostomes

Question 24

Gills are

Flow through respiration with gills

Answer 24

Thin sheets of soft tissues supported by skeletal system

Question 25

Gills are typically made of Flow through respiration with gills

Answer 25

Primary and secondary lamellae which contact numerous blood vessels

Question 26

Water flow through gills lamellae with Flow through respiration with gills

Answer 26

Massive total surface area

Question 27

At gill vessel interface Flow through respiration with gills

Answer 27

Oxygen is extracted from external fluid and channeled to tissue cells

Question 28

More rare respiration

Answer 28

Ram ventilation Air breathing in fishes

Question 29

Water flow is generated by Ram ventilation

Answer 29

Swimming with mouth and operculum open

Question 30

Operculum

Answer 30

Bony cover of the gill

Question 31

Ram ventilation can

Answer 31

Save energy of using muscles of the jaw

Question 32

Oxygen is supplied from Air breathing in fishes

Answer 32

Air through lung or accessory air breathing organs (ABO)

Question 33

Air breathing in fishes evolved in response to

Answer 33

Low level of oxygen in aquatic environments

Question 34

Osmoregulation

Answer 34

The process of maintaining both water and salt balance to prevent body fluids from becoming too concentrated or too diluted

Question 35

Key principle of osmosis

Answer 35

Equalization of concentrations (moving from high to low concentration)

Question 36

Isosmolal

Answer 36

Being at equilibrium (Hagfish)

Question 37

Hyperosmolal

Answer 37

Body has higher concentration (freshwater fishes)

Question 38

Hyposmolal

Answer 38

Body fluid has lower concentration (sharks)

Question 39

Stenohaline

Answer 39

Narrow environmental tolerance Fishes that live in marine or freshwater

Question 40

Euryhaline

Answer 40

Wider environmental tolerance Fishes that migrate for breeding

Question 41

Adaptations to see better

Answer 41

Round lens with high reflective index Lens is moved in and out to adjust visual focus Supply oxygen to the retina to form sharp images

Question 42

Adaptations to lose the eye

Answer 42

Degenerate the eye tissue Absence of the lens is crucial

Question 43

Typical ways to sniff under water

Answer 43

Blind nasohypophyseal pouch Nasopharyngeal duct connected to pharynx Enclosed nasal sac with incurrent and excurrent nostrils

Question 44

Lateral line anatomy

Answer 44

Neuromast organs with hair cells Distributed on head, trunks and tail Embryologically originated from ectodermal placodes

Question 45

Electroreception

Answer 45

Ability to detect external electric fields generated typically by muscle activities to other vertebrates

Question 46

Types of electroreception

Answer 46

Passive Active

Question 47

Ampullary organs made of Passive

Answer 47

Highly conductive gel surrounded by non-conductive wall

Question 48

Sensory cells extend into Passive

Answer 48

The conductive gel to receive electric signals

Question 49

Typically concentrated on the Passive

Answer 49

Head and mouth, but can be found on pectoral fins and rays

Question 50

Likely derived from Passive

Answer 50

Lateral line placode

Question 51

Function for Passive

Answer 51

Orientation, prey detection, social recognition

Question 52

Active organ

Answer 52

Electric discharge organ

Question 53

Homologous with the active

Answer 53

Neuromast organ, not the ampullae

Question 54

Positive pole on the active

Answer 54

Head

Question 55

Negative pole on the

Answer 55

Tail, forms electromagnetic field around the body with the head

Question 56

Function mostly to Active

Answer 56

Locate prey

Question 57

Electrogenesis

Answer 57

Somewhat unique use of the electric discharge organ Induce voluntary muscle controls in prey