Naucrates Ductor
Pilot Fish - Scientific name – Naucrates Ductor
Conservation status
Pilot fish have been listed as Least Concern by the IUCN and are not considered in danger. Although they are eaten by humans they are difficult to catch on a line due to their erratic behaviour but they are sometimes caught and then sold as by-catch.
Overview
They can be found in tropical and subtropical marine waters as well as around the British Isles and into the Mediterranean.
There have been a number of myths around Pilot Fish suggesting they acted as pilots for ships and other fishes. This isn’t the reality though they can follow fishing boats for long periods of time and they are often found close to large fish such as sharks and rays swimming together.
Pilot Fish are coloured dark blue to blackish silver and are distinguished by five to seven bands around their bodies. They have lighter coloured bellies. In moments of excitement or aggression their stripes disappear and their bodies turn silvery-white.
They typically grow to between 60 and 70 cms long and live for up to 3 years in tropical and temperate waters.
Pilot Fish are associated with larger fish such as sharks, rays and sea turtles. The large fish offer Pilot Fish protection while benefitting themselves from being kept free of parasites. Smaller Pilot Fish have been seen swimming into sharks' mouths to clean away fragments of food from between their teeth. (Wikipedia)
Pilot Fish can be found around boats and debris in the sea. They swim at depths of 5 to 30 metres. Their diet includes host's food scraps and small invertebrates. They are prey to tuna, mackerel, and sometimes larger sharks.
Pilot Fish were almost certainly referred to in Herman Melville’s Moby Dick: ‘Shoals of small harmless fish that for some days before had been placidly swimming by our side, darted away with what seemed shuddering fins, and arranged themselves fore and aft with the stranger’s flanks’.
Source
IUCN - https://www.iucnredlist.org/species/190452/44764396
Wikipedia – https://en.wikipedia.org/wiki/Pilot_fish
Sea History - https://seahistory.org/sea-history-for-kids/pilot-fish/
Youtube - https://www.youtube.com/watch?v=qcUqPdhOAZU