PORT PHILLIP BAY


Pilotfish 

Naucrates ductor (Linnaeus, 1758)

View scientific description and taxonomy

Scientific Details

Meristics.
Dorsal fin spines/rays: IV-V; I, 25-29
Anal fin spines/rays: II; I,15-17
Caudal fin rays: 17
Pectoral fin rays: 18-19
Ventral fin spines/rays: I, 5
Lateral line: 133-144
Gill rakers: 6-7 + 15-20

Interpreting fin count meristics.
Spines are in Roman numerals and soft rays are in Arabic numerals. Spines and rays that are continuous in one fin are separated by a comma. Fin sections are separated by semicolons.

Detailed descriptions of fin count and other meristics are in:
Gomon. M.F., Bray, D.J. & Kuiter, R.H. (eds) (2008) Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Order level detail.
A Large and highly diverse group of modern bony fishes many of which have a generalized perch like body form. Most have pelvic fins with one spine and 5 rays and the maxillary bone is excluded from the gape of the mouth. Interrelationships of the group are poorly understood and continue to be studied. They inhabit almost all aquatic habitats from high-altitude strams to the deep sea, although most are marine.

Family level detail.
Streamlined, active-swimming fishes, with fine smooth scales, a relatively short-based spinous first dorsal fin, a long-based soft-rayed second dorsal fin, a narrow tail base and a deeply forked tail; usually a detached pair of short spines before the anal fin. While adults usually inhabit coastal or near shore waters, juveniles are often around floating debris or large planktonic invertebrates such as jellyfish far from land. Many are highly valued gamefishes and some are commercially important.

Taxonomy

Phylum:
Chordata
Subphylum:
Craniata
Superclass:
Gnathostomata
Class:
Actinopterygii
Order:
Perciformes
Family:
Carangidae
Genus:
Naucrates
Species:
ductor

General Description

Body elongate, barely compressed, with nearly symmetrical upper and lower profiles; tail base with a distinct mid-lateral fleshy keel and small dorsal and ventral grooves; first dorsal-fin spines very short and mostly unconnected by membranes in adults; lateral-line scales small, none modified as scutes. Blue above, pale greyish below with 5-6 broad darker bands, 3rd-6th band extending onto bases of dorsal and anal fins; tail dark with pale tips; pectoral and ventral fins yellowish. To 70 cm.

Biology

Pilotfishes accompany larger fishes, marine mammals and turtles, fishes feeding on discarded food scraps. They are also found beneath floating logs and drifting seaweed.

Habitat

Pelagic in tropical and subtropical seas, and often found close to shore.

Open water

Distribution guide

Worldwide.

Species Group

Fishes Trevallies and allies

Depth

Shallow (1-30 m)

Water Column

On or near sea floor Midwater

Max Size

70 cm

Commercial Species

No

Global Dispersal

Recorded in Australia

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Bray, D.J.

Di Bray is a Senior Collection Manager of ichthyology at Museum Victoria.

Author

article author Gomon, M.F.

Dr. Martin Gomon is a Senior Curator of ichthyology at Museum Victoria.

citation

Cite this page as:
Bray, D.J. & Gomon, M.F., 2011, Pilotfish, Naucrates ductor, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 18 Dec 2017, http://portphillipmarinelife.net.au:8098/species/6418

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