5. bryozoa brachiopoda and nematoda
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Transcript of 5. bryozoa brachiopoda and nematoda
Animals that are Moss like
Phylum Bryozoa
Common characteristics
Food capturing organ called a lophophore
Colonial – asexually produced and interconnected
Exoskeleton called a zooecium excreted by individual zooids
No specialized organs for excretion, gas exchange or circulation
Animals that are Moss like
Phylum Bryozoa
Animals that are Moss like
Phylum BryozoaCnidarian Hydroid Polyp Bryozoan Zooid
Animals that are Moss like
Phylum Bryozoa
• Many different growth forms with the zooecium made from calcium, chiton or protein
• Erect and branching– e.g. Bugula sp – The spiral bryozoan
Animals that are Moss like
Phylum BryozoaMany confuse them with hydroids or with corals• e.g. Heteropora sp.the staghorn bryozoan
Animals that are Moss like
Phylum Bryozoa• Some look more like a fungus than moss• e.g. Hippodiplosia sp. the fluted bryozoan
Animals that are Moss like
Phylum Bryozoa
Many others are encrustinge.g. Membranipora sp.
the lacy kelp bryozoan
e.g. Disporella sp.
The purple bryozoan
Animals that are Moss like
Phylum Bryozoa
Byrozoan Polymorphism
Different zooids can perform different functions• Autozooids for feeding
and reproduction
Animals that are Moss like
Phylum Bryozoa• Zooid is a single sex• Colonies are hermaphroditic• Ovicells are brooding chambers in
the colony• Free swimming larva emerge from
ovicell, settle onto a suitable substrate and metamorph
• First zooid in a colony = ancestrula• Forms new colonies by asexual
budding
Animals that are Moss like
Phylum Bryozoa
Byrozoan Polymorphism
Different zooids can perform different functions• Heterozoids for cleaning
and protection
Animals that are Moss like
Phylum Bryozoacommon predators are crabs and nudibranchs
Animals that are Clam like
Phylum Brachiopoda
Common NameLampshells
Common CharacteristicsBivalved shellLophophorePeduncular stalk for
attachment
Animals that are Clam like
Phylum Brachiopoda
They resemble clams • Calcareous bivalved shell (but
not the same size or shape)• Adductor muscle• Mantle
They resemble bryozoans• Lophophore• No special organ for gas
exchange
Animals that are Clam like
Phylum Brachiopoda
Animals that are Clam like
Phylum Brachiopoda
• 350 current species, as many as 30,000 known fossil species
• Dioecious broadcast spawners
Animals that are Worm like
Phylum Nematodaone of the largest animal phyla occurring freely and abundantly almost everywhere
Animals that are Worm like
Phylum Nematoda• Unsegmented with a
cylindrical body shape• Covered by a tough
exoskeleton – collagenous cuticle
• Cuticle sheds (molts) as the nematode grows
Animals that are Worm like
Phylum Nematoda
• Complete digestive tract
• No circulatory system
• Muscles are all longitudinal – thrashing motion
Animals that are Worm like
Phylum Nematoda
• Eutely (constancy of cell number)
• Epithelium is syncytial (many nuclei but not separated by a cell membrane
Animals that are Worm like
Phylum Nematoda• Many parasitic
forms • Cuticle around
mouth with teeth like projections
• Cuticle protects from host digestive juices
Animals that are Worm like
Phylum Nematoda• Dioecious with internal
fertilization• Sperm cells amoeboid
(not flagellated• Females can release
>100,000 eggs per day• No free-swimming larval
stage (emerge from egg as miniature adults)
• Dauer larva (a stage of developmental arrest)