In this episode of underwater relaxation, we would like to become a part of this immense living silver cloud, and simply go with the flow: Bigeye trevally (Caranx sexfasciatus).
A school of fish this size can literally block out the sun. These Bigeye trevallies (Caranx sexfasciatus) have come together in impressive numbers, to cruise over this beautiful sunlit reef. Bigeye trevallies are currently classified within the genus Caranx, one of the groups known as Jacks or Trevallies. This genus itself is part of the larger mackerel family Carangidae. It’s specific epithet (the second part of the scientific name), roughly translates to “six banded”, and refers to the creature’s juvenile colouration. This species of trevally is rather easily identified due to its big eyes, and are one of the most widespread species of them all.
Where to meet the bigeye trevally (Caranx sexfasciatus)
They can be found in massive schools in the tropical waters from the western shores of Central America, all the way to the east of Africa. Actually, the only place they can’t be found is in the Atlantic Ocean. Bigeye trevally normally live close to shore, down to a depth of around 150 metres. However, they do venture out to make offshore seamounts their home as well. They can even make their way upriver into freshwater. As they reach their adult size of about 80 cm, they can easily weigh 10kg.
Behavioural aspects of bigeyes
Caranx sexfasciatus is a voracious predator that relies predominantly on its speed to overpower and surprise its prey. Their diet consists of other fish and crustaceans, which are mainly caught at night. During the day they like to come together to relax. After all, many big eyes see more than one, and in the ocean one always needs to keep an eye out for a bigger fish. This gives them the chance to visit cleaning stations and enjoy their Spa treatment to the fullest extend. An interesting side note about this creature is that although they usually appear silvery and shiny, like many other species of fish they are capable of changing their colour, all the way to a dark black. It is thought that this capability to change colour is helping them to communicate more efficiently amongst themselves, as well as with other species.
Although Caranx sexfasciatus is quite a common sight around the tropical waters of this planet, it is clearly not a boring creature. And when they come together in large numbers, they’re a sight to behold. Not only taking the light but also one’s breath away.