They also feed on chitons, limpets, snails, barnacles, echinoids, and even decapod crustacea. Hundreds of animals, such as sea anemones, barnacles, and hooked mussels, inhabit oyster reefs. Remarkable is the presence of barnacles and sea urchins. Many parasites latch onto whales, notably whale lice and whale barnacles. Green sea turtles have a variety of parasites including barnacles, leeches, protozoans, cestodes, and nematodes. Among the most common predators on barnacles are whelks. Malacostraca have haemocyanin as the oxygen-carrying pigment, while copepods, ostracods, barnacles and branchiopods have haemoglobins. Among these are&colon; the Galician empanada, Galician octopus, scallops, crab, and barnacles. Lichens and barnacles live in this zone. The most common, "acorn barnacles" (Sessilia), are sessile, growing their shells directly onto the substrate. "Ten loads" of barnacles and seaweed were removed. The plates, like in turtle barnacles, are made of calcium carbonate and chitin. Sea turtle shells are an ideal habitat for adult barnacles for three reasons. Whale barnacles are a family of acorn barnacles. Some geophilomorphs are adapted to littoral habitats, where they feed on barnacles.