Do Fish Really Have Fingers? Trivia Quiz

The pelvic fin is found on the lower part of the fish, there are usually two pelvic fins one on each side of the body. The pelvic fins allow the fish to move up and down in water and help to give the fish stability when it is swimming.

There are two pectoral fins, one on each side of the body of the fish. They are located towards the front of the fish, usually just behind the gills. The pectoral fins help the fish to control the speed at which they are swimming and enable them to quickly dart from side to side.

The gills are the fish's respiratory organ which enable the fish to take in oxygen dissolved in water and to get rid of carbon dioxide. The gills have a large surface area and consist of very thin membranes with a blood supply close to the surface and this enables oxygen to diffuse from the water into the blood stream of the fish.

The operculum is the technical term for the bony structure that covers and protects the gills. The operculum helps the fish to get oxygen by opening and closing which creates a change in pressure, forcing water over the gills from which oxygen can then be extracted.

The barbel is a small, sensory organ located on the head of some fish, usually close to or just below the mouth. In fish that have them the barbel contains taste receptors and this helps the fish to ascertain if there is food near them, they are especially common on fish that live in water with low visibility levels.

The name barbel is derived from a Latin word 'barbula' which means little beard.

The caudal fin is often referred to as the tail fin because it is at the end of the fish. The purpose of this fin is to enable the fish to move forward through the water. There are different types of caudal fin depending on their shape and how they connect to the skeleton of the fish.

The lateral line is a sensory organ that runs down the side of the fish. The lateral line contains a series of receptors that can detect changes in pressure and movement of the water the fish is swimming in. The lateral line on a fish usually appears as a series of pores creating a faint line along each side of the fish.

The dorsal fin is located centrally on the top of the fish. The fin helps to keep the fish stable in the water and also helps with movement when the fish is turning or stopping. The pointed dorsal fin of sharks is responsible for the infamous pointed fin sticking out of the water that is associated with sharks nearby.

Like other animals fish use their eyes to see. Most fish can see in colour and some can see ultraviolet or polarised light. The eyes of most fish adjust focus by adjusting the distance between the retina and the lens whereas in most mammals and birds focus is adjusted by muscles which work to change the shape of the lens. Most fish don't have eyelids because the water they swim in keeps the eyes moist, this means that fish sleep with their eyes open.

Different species of fish have different types of mouth, usually determined by how the fish mainly eats. Fish mouths can be turned upwards, point forward or be turned downwards. Usually fish with an upturned mouth, called a superior mouth, feed on fish or insects which swim above them while fish with a downward turned mouth, called an inferior mouth, usually feed on the bottom of the water source they live in. Fish which have a mouth that points straight forward are said to have a terminal mouth and these fish normally eat food which passes by them as they swim.