Naucrates ductor

Author: (Linnaeus, 1758)

Naucrates ductor (Linnaeus, 1758)

Status in World Register of Marine Species:
Accepted name: Naucrates ductor (Linnaeus, 1758) (updated 2009-06-25)

Diagnosis: upper jaw ending below anterior margin of eye; teeth in both jaws minute, in a broad band anteriorly, tapering posteriorly. Dorsal fin IV or V + I + 25-29; anal fin II (completely embedded in large fish) + I + 15-17; soft anal fin base distinctly shorter than dorsal fin base; pectoral fins about equal or slightly shorter than pelvic fins; caudal peduncle grooves present; well-developed cutaneous keel laterally on caudal peduncle. Lateral line slightly to moderately arched above pectoral fins, becoming straight posteriorly; no scutes. Colour: 5 or 6 broad black bands on body and a similar band at end of caudal peduncle; caudal fin banded, with prominent white tips; smaller whit tips on soft dorsal and anal fin lobes. Size: reported to 63 cm for length, common to 35 cm.

Habitat: primarily pelagic in oceanic waters; enjoys a semi-obligate commensal relationship with large sharks, rays and other fishes. Juveniles frequently found in association with seaweeds and jellyfish. Food: scraps of host's food and small fishes and invcrtebrates, possibly ectoparasites of host. Reproduction: see family.

Distribution: eastern Atlantic, northward to Bay of Biscay and as a rare vagrant off the British Isles, also the Azores and Madeira; Mediterranean. Elsewhere, African coast to southern Angola; nearly cosmopolitan in tropical seas.

Eggs, larvae and young stages. Day, 1880, pl. 45 (fig. 2) | Lo Bianco, 1909: 732 | Barnard, 1926: 228 | Weber and Beaufort, 1931: 229, fig. 61-62 | Sanzo, 1931: 1, fig. 1-12 | Padoa, 1956: 564-568, fig. 409-416, pl. 37 (col. fig. 12) | Bini, 1968, 5: fig.
Otoliths (sagitta). Chaine, 1957: 517.