Lobsters

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					   Is many
   people’s
favorite meal,
    the…
Maine Lobster
 really just the
ocean’s version
    of the…
Cockroach??????
Chapter 10 – Class Crustacea

       Kingdom Animalia
       Phylum Arthropoda
           Phylum Arthropoda
             Characteristics
•   “Jointed feet”
•   Exoskeleton made of chitin
•   Bilateral symmetry
•   One-way digestion
•   Sexual reproduction
•   3 cell layers
•   Cephalization-brain concentrated at head
    end
            Class Crustacea
• Includes: lobsters, crabs (snow, king, blue
  claw, hermit, etc), shrimp, copepods, krill,
  amphipods, isopods, and barnacles
• 2 main body segments include the
  cephalothorax and the abdomen
• Carapace covers the cephalothorax
• Leg number varies depending on organism
• Some have swimmerets
       Crustaceans continued
• All crustaceans (and arthropods for that
  matter) must molt
  – New crustacean fills up body tissues with water
    and cracks shell. After new shell hardens,
    crustacean gets rid of excess water.
  – Crustacean is very vulnerable during soft-shell
    stage
Lobster Molting Cycle
Soft shelled crab   empty exoskeleton
                 Lobsters
• Most common are the northern lobster
  (Maine lobster) and the spiny lobster
• Very aggressive and fight amongst
  themselves
• Predators and scavengers – which is why
  they are called “the cockroaches of the sea”
• Can regenerate body appendages (claws,
  legs, etc.) the next time they molt
       Lobsters continued
• One way digestion with mouth,
  esophagus, stomach, intestines,
  anus
• Gills for breathing inside carapace
• Blue-blooded due to hemocyanin
  which uses copper instead of iron
  to bind oxygen
        More Lobster Stuff
• One-chambered heart – open
  circulation
• More advanced nervous system with
  eyes on stalks, cerebral ganglia, ventral
  nerve cord
• Internal fertilization (sperm deposited
  onto abdomen of female) – seminal
  receptacle
Lobsters

				
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