Did you know that fish change colour? Some species do not change colour but many do. This change can be slow or fast. Next time you are out scuba diving, pay close attention to the fish and see if you can spot any changing colour!
Coralia Liveaboard cruises all over Indonesia. Our very experienced dive guides can show you some fish colour changing action!
Watch carefully, in this video you can see a long nose emperor fish changing colour while hunting. It goes from silver to a camo pattern and back to silver in a few seconds!
Slow Colour Changing Fish
Slow changes are generally under the control of hormones. These colour changes are usually semi-permanent. Slow colour changes often happen as a fish changes from its larva stage to juvenile to adult.
The above photos show a juvenile harlequin sweetlips on the left. On the right is the adult version of the same fish. Also take a look at our article Juvenile to Adult – the Amazing Transformations of Fish.
Of course, these slow changes cannot be witnessed during one dive! So we will show you some example of the rapid changes that you can see while diving.
Fast Colour Changing Fish
Fish can change colour very rapidly. If you are not watching closely you will miss it! These fast colour changes are largely under the control of the nervous system. Although hormones may also be involved. One reason for a fast colour change is stress response.
The surgeon fish in the above photo are all the same fish. But have another look to see all the different colours they are displaying. If you want to witness fish colour changing, pay close attention when you next see a school of surgeon fish. They are one of the easiest fish to observe changing colour.
Colour changes can be due to the time of day – night and daylight. They might alter their colour due to changes in habitat or food. Fish also change colour with the seasons.
Schooling Fish in a Rainbow of Colours
While diving you can often see fish rapidly changing colour as they swim over different parts of the reef. Another way to see fish that change colour is to look at schools of fish.
A large school of pinjalo snappers is shown in the photo above. Here the fish are all the same species of fish but they are in lots of different shades of colour.
In the photo below is a school of batfish, also known as spadefish. Again, they are the same fish, but displaying different colours. The underwater world is amazing!
Would you like to know more technical details about how fish change colour? Check out this article by the Australian Museum called Fish FAQ – Can fishes change colour?
Learn More about Marine Life in Indonesia
Have a look at our other interesting articles about marine life in Indonesia in Coralia’s news section: