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Nutrition
Nutrition for the P. camtschatica,
like in habitats, depends on what life stage the crab is in. Red king crab
larvae are planktivores, consuming phytoplankton and zooplankton. As said
before, the abundance of these in the larvae’s environment determines their
survival.1
Small crabs start becoming predators like the
adult forms, feeding on kelp, sea stars, clams, muscles, nudibranch eggs,
barnacles, and molted king crab exuviae (the molted carapace).
The adult red king crabs are more active
predators, migrating to regions with higher supplies of food.2
They are
able to migrate around now because pods are now less necessary, adults are less
vulnerable, becoming more solitary because of their carapace and size. They
hunt at night and are generalized as carnivores, even though they may have
zooplankton time to time. Adults consume fish, mollusks, aquatic marine worms,
aquatic crustaceans, echinoderms, sponges, barnacles, brittle stars, sand
dollars, and sea urchins.3 Picture
on right of an adult red king crab.
The red king crab eats its food by capturing
they prey by its claws, crushing the organism with its right claw and
manipulating it with its left. The king crab then chews and shreds the food by
its mouthparts, the mandibles (crush food), maxillae (move food closer to
mouth), and maxillipeds, enabling the crab to consume a variety of different
organisms. They also have a complete digestive system, the path consisting of
mainly a mouth, digestive glands, which secrete enzymes to aid digestion, and an
anus.
Crabs have an open circulatory system,
consisting of a pumping heart, vessles, and a hemocoel. Hemolymph is pumped out
of the heart, past the gills, bringing oxygen to the hemocoel, the space between
the organs.4
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