1
Q
swim bladder
A
- present in most bony fish
- located below the backbone
- filled with gas controlled by the blood
- provides buoyancy, enabling the fish to remain at a particular depth
- gas is regulated by the nervous system
- serves as an air-breathing lung in lungfish
- sharks, rays + many bottom dwellers lack a swim bladder
2
Q
gills
A
- diffuse oxygen from the water into the bloodstream
- take in water through the mouth and expel it through the gills where it passes through the gill membrane into the bloodstream
- water passes over the gill filaments, which absorb the oxygen and replace it with carbon dioxide
3
Q
heart
A
- consists of two chambers; atrium + ventricle
- blood flows through veins and into the atrium, then to the ventricle
- muscles in the ventricle pump blood through arteries to the gills, where it receives oxygen and gives off carbon dioxide
4
Q
liver
A
- produces bile from the breakdown of old red blood cells
- secretes enzymes that break down fats
- storage area for fats + carbs
- production of blood cells + antibodies
- involved in waste excretion
5
Q
kidneys
A
- located close to the spine in the abdominal cavity
- anterior part of the kidney forms blood
- posterior kidney is involved in osmoregulation → produces urine + helps regulate salt levels in the body
6
Q
digestive system
A
- digestive system leads from the mouth to the vent
- food passes through the pharynx on the way to the oesophagus, which can expand easily for fish to swallow their food whole
- food then passes into the stomach, where it is partially digested
- some fish have their oesophagus or stomach enlarged into a gizzard; which grinds food into small pieces prior to entering the intestines
- digestive process is completed in the intestines
- digested food enters the bloodstream, and waste products pass out through the vent
7
Q
pyloric caeca
A
- located near the junction of the stomach and intestines
- has fringe-like projections
secretes enzymes that aid digestion, and absorb digested food
8
Q
gallbladder
A
- stores + releases bile, which is secreted into the intestine to neutralise acid from the stomach
- helps digest fats in food
- usually a bright yellow or green depending on the colour of bile it stores
9
Q
spinal cord
A
- connects the skull and tail
- made up of numerous vertebrae to house and protect the spinal cord
- connects the brain to the rest of the body
- relays sensory information from the body to the brain and instructions from the brain to the body
10
Q
brain
A
- the control centre of the fish where automatic functions and higher behaviours occur
- all sensory information processed here
11
Q
vent
A
- located in front go the anal fin
- acts as a urinary, digestive and reproductive opening
