Nomeus gronovii

Author: Gmelin, 1788

Nomeus gronovii Gmelin, 1788

Status in World Register of Marine Species:
Accepted name: Nomeus gronovii (Gmelin, 1789) (updated 2009-06-25)

Diagnosis: no teeth on tongue. D IX-XII + 24-28; A I-II + 24-29; P 21-23; pelvic fins large and fan-like, their origin before or under origin of pectoral fin. Vertebrae 41. Colour: mottled and spotted dark blue over white to silvery background; pelvic fins black. Size: to 25 cm SL, but most seen are 5-15 cm.

Habitat: pelagic, offshore in warm waters, most commonly in the shelter of the Portuguese man-of-war Physalia (Siphonophora). Behaviour: large numbers occur in association with floating Physalia, casually swimming in and out of the tentacles and sheltering under the bell. The mottled colour pattern of the fish closely mimics bunched and retracted tentacles. The fish is relatively immune to the toxin of the siphonophore, but none the less is on occasion killed and eaten by its host. Food: tentacles and gonads of Physalia, probably other soft-bodied jellyfishes as well, also zooplankton. Reproduction: eggs and larvae unknown. Specimens as small as 10 mm SL are already found in association with Physalia.

Distribution: not yet recorded in Clofnam area, but widely distributed in Atlantic, Pacific and Indian Oceans; common in the Caribbean, but rare in the eastern Atlantic (reported from north-west Africa and the Canary Islands, thus to be expected).

Eggs, larvae and young stages. No data.
Otoliths (sagitta). No data.