Portuguese man of war

Physalia physalis

ORDER

Cystonectae

FAMILY Physaliidae

TAXONOMY

Holothuria physalis Linné, 1758, Atlantic Ocean. OTHER COMMON NAMES

English: Blue bottle; French: Galère, frégate, vaisseau de guerre hollandais, vaisseau de guerre portugais.

PHYSICAL CHARACTERISTICS

The only pleustonic siphonophore. Colonies consist of a large, purplish blue horizontal pneumatophore that floats on the sea surface, reaching 11.8 in (30 cm) in length in the largest specimens; pneumatophore carries the polyps, which form cormidia at the oral end; at its top, an erectile, longitudinal crest or sail that may be left- or right-handed, all drifting at the mercy of the winds. Pneumatophore asymmetrical; two forms, each the mirror image of the other. Each cormidium consisting of a gastrozooid associated with a tentacle and a gonodendron; however, unlike other siphonophores, tentacle separating from the basigaster during the later stages of development. The tentacles may attain several meters in length; a continuous formation of new cormidia. As the cormidia mature, new gastrozooids gradually lose their tentacles and becoming palpons. Small medusoid gonophores develop at the bases of the terminal palpons. Functional gonophores of a given colony are of a single sex only.

DISTRIBUTION

Widely distributed in tropical and subtropical regions in the three great oceans and in the Mediterranean. (Specific distribution map not available.)

HABITAT

Only pleustonic siphonophore can occur in great numbers (navies); frequently blown ashore by strong winds.

BEHAVIOR

The effect of the wind on the sail is to move the left-handed specimens to the right of the wind direction and vice versa for the right-handed ones. feeding ecology and diet

Feed on small planktonic organisms or small fishes.

REPRODUCTIVE BIOLOGY

Dioecious, release their sexual cells in the sea, development through siphonula larvae.

CONSERVATION STATUS Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

The tentacles can stretch out to many feet (meters) below the float and can inflict powerful and very painful stings on swimmers who become entangled in their tentacles. ♦

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Responses

  • Gioele
    What is the diet of the portuguese manofwar?
    6 years ago

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