Chapter 11 (swim bladders)

Question 1

2 types of gas filled structures

Answer 1

lungs, swimbladders

Question 2

what is the difference between swimbladders and lungs? how are they similar?

Answer 2

lungs are used for respiration while swimbladders provide buoyancy. Both come as out-pouchings of the embryonic foregut. lungs from the ventral side, swimbladders from the dorsal margin

Question 3

2 types of evidence that lungs came before swim bladders:

Answer 3

phylogenetic. early lungs come from ancient actinopterygian lineages.
Anatomical evidence: alveoli resembling those found in lungs of amphibians (gars and bowfin)

Question 4

which paleontologist thinks there is lung-fossil evidence?

Answer 4

Robert. H. Denison

Question 5

if an object weighs more than the equivalent weight of the water it displaces, it:

Answer 5

sinks

Question 6

if an object weighs less than the the water it displaces it:

Answer 6

is positively buoyant

Question 7

how much additional energy would fish have to spend if they didnt have weight reducing adaptations?

Answer 7

5 and 7 % (sw/fw)

Question 8

what are some ways to become neutrally buoyant?

Answer 8

swimbladder, reduce density of bone and fill liver with SQUALENE (oil)

Question 9

what 2 abilities does the hydrostatic function of a swimbladder depend on?

Answer 9

• maintain a gas-filled space inside the body cavity of the fish
• vary the volume of gas in response to changing hydrostatic demands

Question 10

what 2 ways does a swimbladder allow a fish to save energy?

Answer 10

1: able to remain motionless
2: requires less power to swim horizontally

Question 11

what are changes in the swimbladder’s volume proportional to?

Answer 11

the relative not absolute change in pressure

Question 12

what happens to the changes in swimbladder volume the deeper you go?

Answer 12

gets progressively less

Question 13

where does the greatest change in lung volume occur?

Answer 13

near the surface

Question 14

what law describes lung overpressure injury? what does it mean?

Answer 14

Boyle’s law relationship (PV=K). As pressure falls on ascent, the lung volume expands

Question 15

what is a unique property of a swimbladder?

Answer 15

its able to concentrate the partial pressure of oxygen and nitrogen 500 times (O2) and 25 time (Na).

Question 16

2 types of swimbladders, who has em

Answer 16

Physostomous (sturgeon, primitive teleosts), Physoclistous (derived teleosts)

Question 17

how are physostomous swimbladders connected to the foregut?

Answer 17

by the PNEUMATIC DUCT

Question 18

how are physostomous swim bladders inflated?

Answer 18

swallowing air and forcing it into the bladder by the PNEUMATIC DUCT

Question 19

How does deflation of a physostomous swimbladder work?

Answer 19

burping

Question 20

how does a physostomes fish add/remove gas?

Answer 20

for air via gas gland, remove via diffusion

Question 21

how does a physoclistous swimbladder differ from physostomous?

Answer 21

their swimbladders are completly closed: no pneumatic duct. gas comes in and out through SECRETION (at the GAS GLAND) or RESORBTION (at the OVAL)

Question 22

what is more derived, physoclistous or physostomous air bladders?

Answer 22

physoclistous is more derived

Question 23

how do physoclists fill their gas bladders without directly gulping air?

Answer 23

rete mirabile. used to augment the local gas concentrations in the gas gland and not temperatures

Question 24

two important features of the rete mirabile in relation to gasbladder:

Answer 24

1- the close contact between the arterial blood going to teh gas gland and the venous blood leaving it
2- the sheer number of these capilaries

Question 25

the Bohr effect

Answer 25

the decreased affinity of hemoglobin for oxygen with decreasing pH and increaseing partial pressure of CO2
`

Question 26

the root effect

Answer 26

the decreased capacity of hemoglobin to bind O2 even at highest partial pressures.

Question 27

in marine fishes, are swimbladders more common in fishes occupying the epipelagic or mesopelagic zone?

Answer 27

epipelagic

Question 28

what are the swimbladders of vertical migrating mesopelagic fishes filled with?

Answer 28

fats instead of gases

Question 29

three adaptations of deep sea fishes re: swimbladders

Answer 29

1-the longest capillaries in the rete ever observed
2-the greatest root effects ever observed
3-the largest gas glands observed.

Question 30

barotrauma

Answer 30

swollen and tight belly, stomach protruding past the gullet into the mouth, distended and/or crystallized eyes