Comprehensive Description

Read full entry


  Common names: man-of-war fish (English), derivante (Espanol), pez (Espanol)
Nomeus gronovii (Gmelin, 1789)

Man-of-war fish

Body elongate; eye large, with a fatty ring around it; mouth small, usually ends before eye; teeth small, conical, ~ 1 row on jaws; teeth on center and sides of roof of mouth, and on bases of gill arches, but none on tongue; opercle thin, with 2 flat spines;  gill rakers 8 + 15 -19; 2 scarcely separated dorsal fins, IX-XII + I, 24-28, spines fold into a groove, its origin behind (in small specimens directly over) pectoral origin, longest spine slightly longer than longest ray; anal fin I-II, 24-29; pelvics insert before or under pectoral base, fan shaped, attached to belly along entire length, folds into a groove; pectoral rays 19-24, fin pointed and wing-like; scales on head in a broad band, extending before eyes; lateral line complete, high along back. Juvenile with greatly enlarged pelvic fins, round pectoral, deeply forked tail; lateral line ends under end of dorsal fin base.

Juveniles: silvery with black bars and spots, pelvic fins black with white blotches; adults: uniformly dark brown.

Size: reaches 40 cm.

Inhabits surface layers of the high seas; young are associated with drifting Man-of-War siphonophores (Physalia).

Depth: 0-20 m.

Worldwide in warm temperate and tropical seas. The tip of Baja California to the eastern Gulf of California to Peru and the oceanic islands.


Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© Shorefishes of the tropical eastern Pacific online information system.

Source: Shorefishes of the Tropical Eastern Pacific Online Information System

Belongs to 1 community


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!