The Swallowtail Seaperch is one of the most beautiful and colourful fish of the seabed, and it strongly resembles a tropical species. It belongs to the Serranidae family and is a close relative of the grouper and the perch, although its appearance is much more delicate. The body is oval and compressed at the sides with a striking colour that ranges from intense red and pink to gold and orange, depending on the depth and light.

The most characteristic feature consists of the very long and pointed pelvic fins, which look like wings, and the deeply forked tail with tips elongated like those of a swallow. The head is short and rounded, with large eyes that reveal its preference for dark, deep waters. It often bears three characteristic yellow lines on the head behind the eye.

This species loves low light and rocks. It lives in schools near underwater cliffs, caves, and deep rocky reefs where it can find protection. The depth at which it is encountered usually ranges from 30 to 200 metres, although divers have observed it in shallower, dark caves. It is very common on coralligenous seabeds in the Mediterranean.

It is a carnivorous fish that feeds mainly on zooplankton and small crustaceans swimming in the midwater layers. It usually hunts at night or in low light, using its excellent vision to locate copepods and the larvae of other fish carried by currents.

The Swallowtail Seaperch exhibits the phenomenon of protogynous hermaphroditism. All individuals are born as females. They live in harems where a dominant male controls and protects a group of several females. If the male dies or disappears, the largest and strongest female of the group undergoes a hormonal change, changing colour and behaviour to transform into a male within a few weeks and take the position of leader. Breeding occurs mainly in the spring and summer.

Fisheries & Economic Value

The International Union for Conservation of Nature classifies the species as Least Concern due to its wide distribution. Scientific studies consider it an excellent health indicator for Mediterranean coralligenous ecosystems. The presence of large schools suggests a rich and healthy seabed with good current circulation. It has also been observed to function as a cleaner fish in some cases, removing parasites from larger fish such as moray eels.