Fish Anatomy

Question 1

What is a fin used for?

Answer 1

They are used for swimming (locomotion), balance, stability, and steering.

Question 2

What are the different fins called?

Answer 2

Dorsal fin
Anal fin
Caudal fin
Adipose fin
Pelvic fin
Pectoral fin

Question 3

What does the dorsal fin do?

Answer 3

Increase the lateral surface (side) of the body during swimming which provides stability but increases drag.

Question 4

Where is the dorsal fin located?

Answer 4

Located on the fishes back.

Question 5

What does the anal fin do?

Answer 5

It stabilises the fish while swimming.​

Question 6

Where is the anal fin located?

Answer 6

Located on the fishes underside near its anus.

Question 7

What does the caudal fin do?

Answer 7

The tail fin provides the power to move forward. It also acts like a rudder to help steer. Come in different shapes - forked, heart-shaped, square or rounded.

Question 8

Where is the caudal fin located?

Answer 8

Located at the end of a fish.​

Question 9

What does the adipose fin do?

Answer 9

There’s not a known function. Theories say they could function as mechanosensors, detecting water movement directly in front of a fish’s tail fin.

Question 10

Where is the adipose fin located?

Answer 10

Located between the dorsal and caudal fins.

Question 11

What does the pelvic fin do?

Answer 11

Work to stabilise the fish during maneuvers.

Question 12

Where is the pelvic fin located?

Answer 12

Located on the bottom of the fish in front of the anal fin.

Question 13

What do the pectoral fins do?

Answer 13

They do everything that pelvic fins do and help steer and control depth.

Question 14

Where are the pectoral fins located?

Answer 14

Located on either side of the fish near the gills.

Question 15

What are lateral lines?

Answer 15

It detects vibrations and water movement which lets fish orientate themselves in a water current, gain information about their surroundings, and plays a vital role in schooling.

Question 16

What are gills responsible for?

Answer 16

Respiration,
osmoregulation (maintain the balance of water and electrolytes),
excretion of nitrogenous waste,
pH regulation,
hormone production​

Question 17

What are labyrinth lungs?

Answer 17

Allows fish with this adaptation to extract oxygen from air.

Question 18

What do fish eyes do?

Answer 18

Mainly just detect light from their surroundings.

Question 19

How are carnivorous fishes teeth (dentition) adapted?

Answer 19

Their teeth are designed to puncture, hold on to, and cut their prey.​

Question 20

How are herbivorous fishes teeth (dentition) adapted?

Answer 20

Their teeth are more suited for shredding things such as algae.​

Question 21

What do fish scales do?

Answer 21

Protection
Locomotion (how they move)
Different variations come from different compositions and how they balance the two functions.
Older fish species will focus more on protection.

Question 22

What does fishes epidermal mucus do?

Answer 22

Mucus on top of the skin that contains immune components. It’s secreted by globlet cells.
Primary defence against pathogens and microbes.
Barrier between fish and its environment.

Question 23

What is a fishes swim bladder?

Answer 23

A gas-filled organ in the dorsal coelomic cavity of fish.
Its primary function is maintaining buoyancy.
It’s also involved in respiration, sound production, and possibly perception of pressure fluctuations.​

Question 24

What is the process of a fishes (branchial) heart?

Answer 24

Its main function is to pump venous blood (deoxygenated) from the heart to the gills (branchial). branchial and systemic vascular beds (blood vessels) are arranged in series with heart.

Question 25

How is the fish stomach adapted?

Answer 25

In many fish, food is processed in finger-shaped pouches called pyloric caeca, which secrete digestive enzymes and absorb nutrients.​

Question 26

Why do some fish not have a true stomach?

Answer 26

Some fish just have a long intestine. They feed more frequently than predators and their natural food often comes in smaller bits. So they don't need a stomach to start the digestion process.

Question 27

Why are freshwater fishes kidneys larger than saltwater?

Answer 27

In both groups the kidney excretes wastes from the body. The kidney of freshwater fish also excretes large amounts of water to counteract the water absorbed through the skin.​

Question 28

What is the purpose of the liver in fish?

Answer 28

Important for glucose and lipid metabolism, immunity, and detoxification in fish.

Question 29

What is the function of the gall bladder in fish?

Answer 29

The liver makes bile and stores it in the gall bladder until a bolus (compact, partially digested food) passes the stomach. The bile is then expelled into the intestine. Bile contains waste products of liver activity which pass out of the fish in the faeces.​

Question 30

What do fish gonads do?

Answer 30

The female gonad produces oocytes (develping eggs) with follicles through type II division. By contrast, in males, germ cells keep dividing as type I germ cells during both the embryonic and the larval stages.​

Question 31

What is the genital opening (papilla) in fish?

Answer 31

A small, fleshy tube behind the anus. Sperm or eggs are released from it. The sex can be determined by the shape of its papilla.​

Question 32

What are the fish reproductive organs?

Answer 32

Gonads are fish reproductive organs. They are often paired, internal, and located next to the stomach. Females have two ovaries that produce eggs. Males have two testes that produce sperm.​