#chthamalus

Chthamalus

Slightly puzzled here - I thought these were the Six-plated Barnacles, C. antennatus, but it appears that species is only found over in the South-east. I could be wrong, either way - barnacles are a highly diverse clade, as Darwin learned when he sat down to write the authoritative text on the animals (his first major work, in fact). Unsurprisingly, he was sick of the sight of them by the time he finished, but his work on them made his reputation well before the publication of Origin of Species.

Barnacles are crustaceans, despite the resemblance to molluscs, and the most familiar species glue themselves upside down to the rock, grow calcareous armour plates and doors to keep in the water, and spend the rest of their lives kicking food into their mouth. And having sex with their neighbours via their gigantic penises.