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Class Crustacea Sub Phylum Mandi

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Class Crustacea Sub Phylum Mandi Powered By Docstoc
					Sub Phylum Mandibulata Class Crustacea
                                                         But there are some constraints
 Sub Class Malacostraca                             Hydrostatic skeleton is of no use
                                                    Reduction of coelom: main body cavity is hemocoel

                                        Sub Class
                                        Copepoda


Sub Class Cirripidea       Sub Class Branchiopoda




             D. Subclass Cirripidiea                            D. Subclass Cirripidiea

                                                      Acorn barnacle

                                                     All barnacles are marine
                                                     Exclusively affixed
                                                       (also on ship hulls)
                                                     Live within CaCO3 shell
                                                          made up of plates
  Acorn barnacle                                     Head is greatly reduced
                                                     Suspension feeders
    > one thousand spp
    Gooseneck barnacle




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       Barnacle feeding mode varies                                       Life Cycle

          with velocity of flow             •  Eggs hatch into nauplius

                                            •  Molts 6 times and turns into
                                               cypris larva

                                            •  Cypris larva finds place to attach
                                            •  Secretes cement from cement
                                               glands on the 1st antennae to
                                               attach
                                            •  Develop into adult


   Active                         Passive
            Suspension Feeding




Pass through a planktonic nauplius then a
 cyprid stage before becoming affixed          Parasitic (Rhizocephalan) Barnacles




                                                                                        2
                                                           Diagram of rock crab infected
                                                           by a rhizocephalan barnacle


               Rhizocephalan
                Infection




                   SubClass                                           Copepoda
    A. Copepoda           B. Branchiopoda          -- Focus of intensive studies on suspension feeding
                                                   -- Acute selection for food size, quality

                                                   Feeding Vortices           Acartia fed diatoms cultured in
                                                                              high and low nutrient conditions




Most Marine, some F.W.    Most F.W., few marine
Feed on microscopic algae “Lawn mowers of lakes”




                                                                                                                 3
Cladocera Reproduction                             Cyclomorphosis:
                                                   -- morphological changes in response to predators
    Cyclic
Parthenogenesis                                    -- usually involves a developmental change that is
                                       Amictic
                                                     induce by chemicals released from predator


                                                   The different heads
                                                   of Daphnia
                                                   retrocurva




                           Mictic




          C. SubClass Malacostraca                            Life Cycle of the Blue Crab
                                                                 in the Chesapeake Bay
                  Decapoda




  Active lifestyle
  1500 species of crabs, in every marine habitat
  In humid tropics adults live entirely on land                          Crab zoea




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