Fish Anatomy Flashcards
What is a fin used for?
They are used for swimming (locomotion), balance, stability, and steering.
What are the different fins called?
Dorsal fin
Anal fin
Caudal fin
Adipose fin
Pelvic fin
Pectoral fin
What does the dorsal fin do?
Increase the lateral surface (side) of the body during swimming which provides stability but increases drag.
Where is the dorsal fin located?
Located on the fishes back.
What does the anal fin do?
It stabilises the fish while swimming.
Where is the anal fin located?
Located on the fishes underside near its anus.
What does the caudal fin do?
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.
Where is the caudal fin located?
Located at the end of a fish.
What does the adipose fin do?
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.
Where is the adipose fin located?
Located between the dorsal and caudal fins.
What does the pelvic fin do?
Work to stabilise the fish during maneuvers.
Where is the pelvic fin located?
Located on the bottom of the fish in front of the anal fin.
What do the pectoral fins do?
They do everything that pelvic fins do and help steer and control depth.
Where are the pectoral fins located?
Located on either side of the fish near the gills.
What are lateral lines?
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.
What are gills responsible for?
Respiration,
osmoregulation (maintain the balance of water and electrolytes),
excretion of nitrogenous waste,
pH regulation,
hormone production
What are labyrinth lungs?
Allows fish with this adaptation to extract oxygen from air.
What do fish eyes do?
Mainly just detect light from their surroundings.
How are carnivorous fishes teeth (dentition) adapted?
Their teeth are designed to puncture, hold on to, and cut their prey.
How are herbivorous fishes teeth (dentition) adapted?
Their teeth are more suited for shredding things such as algae.
What do fish scales do?
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.
What does fishes epidermal mucus do?
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.
What is a fishes swim bladder?
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.
What is the process of a fishes (branchial) heart?
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.
How is the fish stomach adapted?
In many fish, food is processed in finger-shaped pouches called pyloric caeca, which secrete digestive enzymes and absorb nutrients.
Why do some fish not have a true stomach?
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.
Why are freshwater fishes kidneys larger than saltwater?
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.
What is the purpose of the liver in fish?
Important for glucose and lipid metabolism, immunity, and detoxification in fish.
What is the function of the gall bladder in fish?
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.
What do fish gonads do?
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.
What is the genital opening (papilla) in fish?
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.
What are the fish reproductive organs?
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.
