BIO 469 Lecture Notes - Lecture 5: Zooid, Gymnolaemata, Phylactolaemata
13 Jun 2018
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Lophophorate Phyla
● Phylum Bryozoa
● Phylum Entoprocta
● Phylum Brachipoda
● Phylum Phoronida
○ Mouth develops from blastopore (Phoronida)
○ Larva of some -- modified trochophores
○ Can make chitin -- not found in deuterostomes
○ Bilateral symmetry
○ Circular or horseshoe-shaped food catching organ -lophophore
○ Body and coelom more or less in 3 divisions.
○ Lophotrochozoa (characteristics) EXAM
■ Trochophore Larvae
■ Lophophore
Phylum Bryozoa
● Marine, freshwater
● 5000 living species
● 15,000 fossil species
● >87 species in Bermuda
● Sessile and colonial
● Shrub-like or flat
● Boring
● Fouling organisms
● Eaten by non-selective scarpers (urchins), nudibranchs,pycnogonids (sea spider)
● Class Stenolaemata - marine
○ Living Species; >500 fossil genera
● Class Gymnolaemata - mostly marine
○ Majority living, and many fossil
○ Common, abundant found to 8200m
○ Mostly found on rocks, pilings, algae, mangrove roots, dead shells, other animals
● Class Phylactolaemata - freshwater
● Colony = zooarium
● Individual zooid lives in a zooecium
○ Zooecium is secreted by epidermis
■ Chitinous
○ Cystid = exoskeleton and body wall
○ Polypide/Lophophore = contents of zooid within body wall
○ Protein-chitin cuticle or cuticle overlying calcium carbonate
● Exoskeleton structure and colonial organization used in identification
● Coelom divided into 3 cavities
○ Proto; near brain
○ Meso; cavity inside the lophophore
○ Meta; column inside the body of organism
● Tentacles arranged in circular structure, protruded through orifice
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Document Summary
Can make chitin -- not found in deuterostomes. Circular or horseshoe-shaped food catching organ -lophophore. Body and coelom more or less in 3 divisions. Eaten by non-selective scarpers (urchins), nudibranchs,pycnogonids (sea spider) Mostly found on rocks, pilings, algae, mangrove roots, dead shells, other animals. Polypide/lophophore = contents of zooid within body wall. Protein-chitin cuticle or cuticle overlying calcium carbonate. Exoskeleton structure and colonial organization used in identification. Meta; column inside the body of organism. Tentacles arranged in circular structure, protruded through orifice. Zooids are microscopic, colonies can be 24cm high (erect species) or 50cm in diameter (encrusting species) One encrusting colony can have as many as 2,000,000 members. In some colonies, zooids share nutrients via the funiculus. Vibracula - operculum modified as setae to brush the colony clean. Tissue generation (excess cells), move through digestive system and out through anus. A colony may have zooids that are both male and female or zooids that are either male or female.
