C. Pipitone et al., Diet of pilotfish, Naucrates ductor (Carangidae), associated with FADs in Sicilian waters (central Mediterranean)., CYBIUM, 24(4), 2000, pp. 415-418
Pilotfish, Naucrates ductor, are taken as a by-catch of the dolphinfish FAD
(fish aggregating devices) fishery in Sicilian waters. In order to assess
the diet of this poorly known species, the stomach contents of 80 specimens
(between 21 and 29 cm SL) were analysed. Fishes were sampled between Octob
er 1994 and January 1995 on board of purse seiners fishing off NE and SE Si
cily (central Mediterranean). Pelagic crustaceans (especially hyperiid amph
ipods) were the most abundant dietary item, followed by pelagic gastropods
(Atlantidae) and fish larvae. Pilotfish seem to have a planktivorous diet u
p to a length of about 30 cm (age 6 months); larger specimens become unavai
lable to sampling, probably because they abandon floating objects and take
an erratic attitude in open waters. The link of pilotfish with floating obj
ects is still not clear, though several hypotheses (protection, visual stim
ulus and help in predation) are suggested.