Something different on Lahinch beach today.
is a genus of free-floating Hydrozoans
that lives on the surface of the open ocean, worldwide, and is commonly known by the names by-the-wind sailor
, purple sail
, little sail
, or simply Velella
. The most common, and perhaps the only species encountered is Velella velella
These small cnidarians
are part of a specialised ocean surface community that includes the cnidarian siphonophore Portuguese Man o' War
and some specialised molluscan nudibranchs
), including Glaucus
and the purple snails Janthina
, that prey on them. Each Velella
is a hydroid colony, and most are less than about 7 cm long. They are usually deep blue in colour, but their most obvious feature is a small stiff sail that catches the wind and propels them over the surface of the sea. Under certain wind conditions, they can become stranded on beaches in the thousands.