Among all fins that a fish possess, only caudal fin is connected to vertebral column and this gives strength to the caudal fin to be used for propulsion and thrusts while swimming or changing directions or accelerated movements.
Based on their shape caudal fins are categorized in different types, namely pointed, rounded, truncate (square), emarginated, forked, lunate and heterocercal etc. The shape of a fish's caudal fin indicates how the fish moves and lives as well.
Here we are discussing how we can classify fishes found in our region on the basis of their caudal fins.
Leaflet of caudal fins
1- Observe the caudal fins of fishes found in your region. Focus on a fish and observe its caudal fin and try to identify its fin type with the help of caudal fin leaflet.
2-While observing the caudal fin, also observe the fish movements and note how it is using its caudal fin in movements.
3- Draw the sketch of fish and mark characteristics of its caudal fin. You can also take the photograph of the fish or take a video of its movement.
4- If you are belonging to fisher family you can conveniently observe and examine the caudal fin of different fishes caught. You can also relate the fish habitat and fish behaviour in reference to their use of caudal fin.
5- Alternatively, you can visit the local fish market or fishing areas and can examine and document the caudal fins of different fishes.
6- You can distinguish fins on the basis of their morphology and anatomy (viz. Shape, size, dimensions, fin rays, colour, thickness etc.)
● Record the Name of Site of observation along with date and time.
● Make a list of the fishes observed and record its caudal fin type (using the caudal fin leaflet)
● Draw the sketch of caudal fin of respective fish
● Draw the sketch of respective fish
● Draw the sketch of fish’s movement and orientation of caudal fin
● You can present a record of the fish diversity on the basis of caudal fins; classification of fishes according to fin types, morphological characters of caudal fins.
● You can present your finding numerically and/or qualitatively or through sketches, photographs and drawings.
● Fish morphology
● Caudal fin morphology
● Use of caudal fin for fish movements
● Fish habitat and adaptations of caudal fins
● Categories of fishes on the basis of their caudal fins
● Fish behaviour and use of caudal fin
● Is it possible to design the oar of a boat like that of a fish fin?
● Can we make an oar having shape and corresponding propulsion power following the caudal fin of a fast swimming fish?
● Does there exist any fish that is devoid of caudal fin / or all fins? If yes, how do they swim without having fins?
Fish shape and anatomy helps us discover information about how a fish moves, where and how the fish lives, and how it has adapted to its environment. By studying the morphology of living things, humans have learned how to better design machines such as submarines, torpedoes, airplanes and automobiles. Body shape, mouth location and size, tail shape and color all give indication of how fish live and function.
