Holothurians, or "sea cucumbers", or even as the foul-mouthed fishermen call them, "sea dicks", belong to the echinoderms, in the same class of animals with starfishes and sea urchins. Usually they are stuck next to seaweeds or wedged in some cavity and are rarely seen searching for food sliding slowly to the seabed, as they are mainly nocturnal animals. There are about 35 species of sea cucumbers in greek seas. One of them, the Holothuria sanctori in the photo, features an excellent defense mechanism that is reminiscent with the way Spider-Man wanders. When something touches them, they eject a dense, sticky and slightly toxic web that sticks to the body of the unfortunate predator.