Bluebottle
In recent weeks beaches around Sydney have been inundated with bluebottles. You will see them either on the sand or in the water.
So what is a bluebottle.
A good place to start in defining a blue bottle is to say what it is not. Although related the bluebottle is not a jellyfish. It is known as a siphonophore.
The most common bluebottle found in the waters around Sydney is Physalia utriculus.
The discussion becomes more interesting when you realise that the bluebottle is not one animal but a grouping of four different colonies of polyps. The word collective comes to mind.
The colonies rely on each other to survive.
One of the colonies is the gas filled sac that floats on the surface of the water. You may see a grouping of bluebottles on the sand as they are often left stranded on the beach waiting for the tide to rise and take them back into the ocean.
The three other colonies in the arrangement are ones for catching prey by stinging it, one for digesting the prey and of course one for the continuation of the species, reproduction.
The bluebottle does not mate but instead reproduces asexually.
Bluebottles are carnivorous feeding on larval fish, small crustaceans and molluscs (snails and clams).
These creatures come to their earthly end when the bluebottle zaps them with venom located in the long tentacles that trail the sac, resulting in the creature being paralysed. The prey is then drawn to the mouth of the bluebottle by the tentacles and consumed.
In Spring and Summer strong winds are responsible for bringing bluebottles to Australian shores. In the other months of the year they exist offshore.
The bluebottles that appear in Australia are sometimes called Pacific Man o’ War. They are less venomous than the Portuguese Man o’ War which is found in the Atlantic.
The name Portuguese man o’ war originates from the resemblance of this siphonophore to 18th-century Portuguese warships when those warships were at full sail.
There you have it a floating warship that can declare war on you whilst swimming or surfing at the beach.