When we as a team first visited Lizard Island at the northern end of the Great Barrier Reef as long ago as 1978 we asked the then Director whether anyone there ever saw Portuguese men-o-war, Velella or Porpita. The answer was "no, never, except the odd very small blue bottle" - the man-o-war. It was to our great surprise and delight therefore when on the back of a minor hurricane we caught Porpita. What we were not prepared for though was anything other than the inky blue-green individuals we all had met in the Atlantic on earlier trips.

By painstakingly stalking the deep water channel, three miles out from the island, with eyes squinting against the glare and straining to distinguish blue on blue over the two or three days of calm immediately following the powerful north easterly blow, we were completely gob-smacked to spot a bright sulphur yellow individual drift by - no bigger than a dime. Our immediate reaction was "mutant" -"albino" (or its yellow counterpart!) "Sport" - "freak" - "dying" - "dead"!

Carefully bucketed and scrutinized we realised that this was no storm-damaged individual, and certainly it was not dead nor, as far as we could tell, was it dying. We contained it in a thermos and looked for less bizarre individuals. We could not believe our eyes when within half an hour we had caught one pure white, three blues and another sulphur yellow.

Various colour morphs of Porpita porpita

Photograph by Peter Parks

Since then, we have never failed to find Porpita on Lizard Island and on two other occasions we found many a white or yellow individual. To this day we have met no one else - professional or amateur - who has seen, heard of or found such variations and it is now our belief that these pale-coloured animals are perfectly healthy colour variants.

Zooxanthellae of Porpita porpita

Photograph by Peter Parks

Interestingly they all contain Zooxanthellae and the darker areas in the photographs are aggregations of these microscopic algal cells. How bright white and yellow Porpitas survive the attentions of petrel's, frigate birds and gulls we may never know, but as far as we can tell they are relatively common and as viable as the normal blue-green versions.

This article was written by Peter Parks

If you have an article of general interest that you would like considered for the article of the month then we would love to hear from you. If you are also able to supply images then we can include those as well. You can email us at iq3d@imagequest3d.com