Mediterranean Rainbow Wrasse – Coris Julis
Description, Features & Anatomy
The Mediterranean Rainbow Wrasse has an elongated, slightly high-backed and laterally squat body and can grow up to 25cm long. All specimens over 18cm are male.
Both males and females, as well as the young have an individual appearance.
In contrast to the adult males, young Mediterranean Rainbow Wrasses are quite simply coloured. Their body consists of horizontal, white and black lines. The fins are intensely yellow and the eyesare yellow, white, red striped with black pupil.
Also the female representatives of Coris Julis are rather inconspicuous. The side line of the fish separates the brown back from the white belly. The eye is predominantly bright red with a black pupil.
The male Mediterranean Rainbow Wrasse is the actually colourful one in the family. Its belly is still boringly silvery, but his back is all the more colourful. Orange, pink and turquoise determine the colouring, as in the young animal in horizontal lines. A yellowish glimmer comes through here and there.
Its colour can easily be confused with the Ornate Wrasse, which is just as colourful but has a completely different pattern.
Habitat & Distribution
Coris julis can be found above algae covered rocky reefs and in seagrass meadows to a depth of 120m. They prefer coastal sea areas.
When diving on the Canary Islands you can see him from time to time.
Its general distribution ranges from the Black Sea over the Mediterranean Sea to the North-East Atlantic. In the latter it can be found from Sweden, along the European and African coasts to Gabon. The Mediterranean Rainbow Wrasse can also be found around the Azores and Madeira.
Lifestyle & Nutrition
Coris julis is a day-active fish. Its sleeping behaviour depends on temperature and lighting conditions. While it is awake in summer from 6 am to 8 pm, in winter it is only from 8:30 am to 3:30 pm. To sleep, they dig into sediment. The same can also happen as an escape reaction.
The diet of the Mediterranean Rainbow Wrasse is varied. Besides snails, crustaceans, mussels, small fish and echinoderms, the menu also includes benthic algae. Juvenile specimen also show the behaviour of cleaner fish from time to time.
Reproduction & Development
First it should be mentioned here that the Mediterranean Rainbow Wrasse is a sequential Hermaphrodite. I.e. it can be that it changes its sex in the course of his life. Most young fish develop to females, whereby it can also be that they immediately become males and nevertheless have the appearance of the female. These are so-called primary males. In addition, it is possible that females later turn into males and assume the typical appearance. These are the secondary males.
With approximately one year Coris julis is sexually mature. The reproductive period is between July and September. Everything begins with the mating position of the female. Thereupon it is orbited by a secondary male and both partners swim in a spiral towards the water surface. After a rise of approx. 3m the female turns on the back, where the couple then ejects its germ cells. So the eggs are fertilised pelagically.
Sometimes a primary male cheats himself into the reproduction ritual. However, these are usually driven out by the secondary males.
Sources & Links
Images of male and female: