Buoyancy

Question 1

State the ways in which fishes achieve buoyancy (both active and passive/static ways).

Answer 1

1) Using pectoral fins for general lift
2) Substituting protein for fat or lipids and by substituting calcifying bones for cartilaginous ones.
3) They have a swim bladder to help with lift.

Question 2

What type of fishes does not have a swim bladder?

Answer 2

1) Pelagic fishes like the nototheniidae
2) vertical migrators
3) fishes that swim continuously over wide depths

Question 3

What percentage of bony fish have swim bladders?

Answer 3

50%

Question 4

What are the types of swim bladders?

Answer 4

physoclistous and physostomous

Question 5

What is the three ways of lipid storage within fishes?

Answer 5

1) Squalene
2) Wax esters
3) Lipids

Question 6

What are the advantage and disadvantages of storing lipids within the fish?

Answer 6

Dis: fine-tuning is difficult & Buoyancy linked to metabolism

Ad: Buoyancy does not vary with depth.

Question 7

What is the advantage and disadvantage of reducing dense materials like calcified bones?

Answer 7

Dis: Restricted movement
Ad; Buoyancy doesn’t vary with depth

Question 8

How do fishes generate general lift? which is an active way of gaining buoyancy.

Answer 8

By using their pectoral fins

Question 9

What is the advantage and disadvantage of general lift/ actively achieving buoyancy ?

Answer 9

Dis: High energy is required & must maintain a certain speed
Ad: Can move freely up and down through the water column.

Question 10

What is buoyancy?

Answer 10

How fishes maintain their vertical position within the water column

Question 11

True or false? Primitive fishes had a gas bladder and lacked lungs.

Answer 11

False. Primitive fishes has lungs and due to evolution developed gas bladders instead which are known as swim bladders.

Question 12

What are the three purpose of the gas bladder/ swim bladder?

Answer 12

1) To detect sound
2) Produce sound
3) Achieve buoyancy.

Question 13

How does the swim bladder achieve buoyancy?

Answer 13

By adjusting the amount of air that fills the bladder. Aka changing the size of the bladder.

Question 14

Which type of swim bladder lacks a pneumatic duct?

Answer 14

Physoclistous. It has a network of capillaries that help transport gases to the bladder to change its size.

Question 15

Which swim bladder has a pneumatic duct?

Answer 15

Phytsostomous. Fishes with this type of swim bladder swims to the surface of the water and gulp for air. To release air they burp.

Question 16

What is the disadvantage of the physostomous swim bladder?

Answer 16

dis: Fine tuning is difficult

Question 17

Which swim bladder derivedd from the primitiave sac?

Answer 17

Physostomous

Question 18

what connects the swim bladder to the gut in the physostomous swim bladder?

Answer 18

The pneumatic duct

Question 19

How was the physostomous bladder derived?

Answer 19

dervied as out pocket from gut.

Question 20

Where does the gas exits in the physostomous bladder?

Answer 20

Pneumatic duct

Question 21

How does the physostomous bladder colelct air?

Answer 21

Gulping or diffusion from gas gland

Question 22

Name the four secretion methods for gas into ad out of the swim bladder.

Answer 22

Root and Bohr effect, Salting out, Rete Mirable and countercurrent exchange

Question 23

True or false. A fixed amount of gas will have greater buoyancy at greater depths.

Answer 23

False.

Think about it and provide an explanation.

Question 24

How does the physostomous swim bladder add and release gas?

Answer 24

Gulping via the Rete mirable and gas gland
Burping via pneumatic duct

Question 25

What is the disadvantages of the Physostomous swim bladder?

Answer 25

Hard for fishes to discent at lower depths, higher risk for aerial predation, dependant on surface.