During the decompression phase it often happens to be visited by some species of fish that intrigued approach the diver and the support boat. Today we received the visit of the Pilot Fish Naucrates ductor. It is a rather rare encounter because this species of fish lives in symbiosis with the “big of the sea” such as sea turtles, manta rays, rays but above all the sharks.
However, it often happens that adult specimens abandon their host to replace it with ships and passing boats from which they probably think they will benefit from it. In even rarer cases they approach the scuba diver intrigued by the bubbles and the size of the strange new individual, to follow him in decompression even under the boat.
In our case we are in the open sea on a depth of 80 meters where the diver during a deep dive met our pilot fish who followed him during the ascent to the bottom of the boat.
Naucrates ductor, commonly known as Pilot fish, is a saltwater fish belonging to the Carangidae family, the only exponent of the genus Naucrates.
Distribution and habitat
This species is widespread in the coastal waters of temperate and tropical seas around the globe, including the Mediterranean Sea.
The appearance is typical of the Pelagic Carangidae, in fact the body is elongated, with a rounded head. The fins are strong and muscular and the tail is bilobed. The livery is white-gray with wide black bands. The young have white-yellow livery with fringed brown stripes. It can exceed 50 cm in length.
Coexistence with jellyfish
Young specimens, like those of other species of the family, tend to take shelter in the umbrella of the jellyfish, living with them, taking advantage of the protection they provide and perhaps feeding on the leftovers of their prey.
The adult specimens, on the other hand, usually follow ships, sea turtles, manta rays, rays but above all sharks.
The relationship of this fish with sharks is described as almost symbiotic and it is extremely rare that a shark feeds on a pilot fish so much so that we often notice small pilot fish swimming in the mouth of the sharks to feed on the food residues left between the teeth. , parasites, leftover food and even shark droppings, providing a cleaning “service” in return.
The only species that poses a danger to pilot fish is dolphinfish.