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| Photo Information |
Copyright: Robin O'Connell (roconnell)
![Gold Star Critiquer/Gold Note Writer [C: 155 W: 0 N: 61]](http://i1.treknature.com/misc/g-n-g.gif) (404) |
| Genre: Animals |
| Medium: Color |
| Date Taken: 2007-10 |
| Categories: Cnidarians |
| Photo Version: Original Version |
| Date Submitted: 2007-11-01 17:11 |
| Viewed: 951 |
| Points: 4 |
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| [Note Guidelines] Photographer's Note |
The Bluebottle or Portuguese Man-of-War (Physalia physalis), is not a single animal but a colony of four kinds of highly modified individuals (polyps). The polyps are dependent on one another for survival.
The float (pneumatophore) is a single individual and supports the rest of the colony. The tentacles (dactylozooids) are polyps concerned with the detection and capture of food and convey their prey to the digestive polyps (gastrozooids). Reproduction is carried out by the gonozooids, another type of polyp.
The float is a bottle or pear-shaped sac that can exceed 15 cm. It is mainly blue, though its upper margin may show delicate shades of green, pink or purple. It is a living, muscular bag that secretes its own gas, which is similar to air. The float has aerodynamic properties and it seems likely that sailing characteristics may be modified by muscular contraction of the crest. Physalia sails at a slight angle downwind and the course is determined by the curvature of the float and the underwater resistance of the rest of the colony. The float may project either to the left or to the right; the left-handed forms sail to the right of the wind and vice versa. Thus, if the sailing angle of one form leads to its stranding on the shore, the others sailing to the opposite side of the wind may escape.
(Source: Austrailian Museum Online)
This "Ili Mane`o, Pa`imalau, Palalia or Pololia" was photographed on Waimanalo Beach, Oahu. They commonly wash up on the East Coast of Oahu, during strong onshore winds. The man-of-war are found most often in the tropical and subtropical regions of the Pacific and Indian oceans, and the northern Atlantic Gulf Stream. It is sometimes found floating - some even say "swarming" - in groups of thousands.
Kingdom: Animalia Linnaeus, 1758 - animals
Subkingdom: Radiata (rad-ee-AY-tuh) (Linnaeus, 1758) Cavalier-Smith, 1983 - radiates
Infrakingdom: Coelenterata Leuckart, 1847
Phylum: Cnidaria Hatschek, 1888 - cnidarians
Subphylum: Medusozoa Petersen, 1979
Class: Hydrozoa - hydrozoans, hydroids, hydralike animals
Order: Siphonophora - siphonophorans
Family: Physaliidae
Genus: Physalia (Linnaeus)
Species: physalis (Linnaeus, 1758)
Scientific Name: Physalia physalis (Linnaeus, 1758) |
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- anel
(7094)
- [2007-11-02 6:51]
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hello Robin,
What an amazing creature! And what a colour!
Thanks for this unusual post
Anne
very interesting, TFS Ori
