This is a blue ocean slug (Glaucus atlanticus) that was washed ashore with a mass, multi-day stranding of thousands of blue bottles (Physalia physalis). These nudibranchs are part of the rarely seen blue community of the open ocean. They prey on other animals in that community, such as Physalia physalis, by-the-wind-sailors (Velella velella), blue buttons (Porpita porpita), and violet snails (Janthina janthina). Glaucus nudibranchs are immune to the venom of the blue bottles that they consume. They store their prey’s nematocysts and deploy them in specialized cnidosacs at the tips of their ornate cerata. Because these nudibranchs concentrate the venom of their prey, they can produce a more powerful sting than Physalia.
Add to Cart Add to Lightbox Download