Bluebottle

Description:

This bluebottle caught my eye, and despite it being beached, it was still moving. Note the slug-like polyp on the left - it was swelling and rising from the top of the float, then it would relax (compare photos 1&2, then 3&4). I observed it doing this several times, almost as if riding piggyback, and when swollen a large "eye" seemed to appear. I've seen thousands of bluebottles, but I have never seen anything quite like this. Even image searches have failed to show anything similar. Aka Indo-Pacific man o' war, this species is not a true jellyfish. The best way to describe this animal? Well, it is not a single animal but a colony of four kinds of highly modified individuals (zooids). The zooids 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. Although smaller and less venomous than its larger cousin the Atlantic Portuguese man o' war (Physalia physalis), the bluebottle can also occur in swarms, but unlike P. physalis, no fatalities have been recorded for P. utriculus stings.

Habitat:

Had just washed up on the beach. North Avoca Beach, Central Coast NSW. Very gentle onshore breeze. I only spotted this one individual, or more accurately, one colony of four specialised zooids.

Notes:

When I was a child, it was almost like a right-of-passage to be stung by a bluebottle. Only then were we considered real ocean-goers. Over the years I've received multiple stings, but that's par for the course. I tell my New Australian friends that, even when they've received their citizenship papers, they aren't fully-nationalised until they've also been stung by a bluebottle. They could do a lot worse.