Mollusc can feed on new feeding strategy and it may

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Unformatted text preview: ls this animal has the smallest body plan moving up into terrestrial environment snails have slight change in respiratory system - complexiy: organism increases size of visceral mass - shell is grown faster on one size and is wound around and inside shell(visceral mass) front and back of organism are pulled inside - piece of shell locks into place and cannot be dried out Figure 25.25a BIO1130 Organismal Biology Université d’Ottawa / University of Ottawa BIO1130 Organismal Biology 69 2:25 PM Page 23 Phanerozic - Paleozoic Foot modified as a series of tentacles muscles in tentacles and arms a re used head and posterior end coming togehter not a great strucure- tipped over on side first of all molluscs have conical shells Squids and octopods (Cephalopods) Mouth Mantle Anus Gill Figure 25-22 BIO1130 Organismal Biology 70 Université d’Ottawa / University of Ottawa 2:25 PM armored predator- easy to find- major preadators back at that point in time such an effective predator because it is a predator within a protected case nautolists only remnant of shells cephlapods new type of fish comes into ocean- then they are at a distinct disadvantage pressure to lose shells and become squids and octopods Ammonites BIO1130 Organismal Biology 71 Université d’Ottawa / University of Ottawa 2:25 PM turned into sendentary filter feeder shell is squeezed and viscera and food wrapped inside of shell cypehens sitting at water surface pumped in and out of mantle cavity Water passes over water surface of gills Clams (Bivalves) Anus Figure 25-27 Gill Mouth Digestive system loss of radula becomes derived trait more or less sendentary(notmoving around) lost cephilization spet at sendentary filter feeding Foot Figure 25-27 Mantle BIO1130 Organismal Biology Université d’Ottawa / University of Ottawa BIO1130 Organismal Biology 72 2:25 PM Page 24 Phanerozic - Paleozoic Food particles Three main protostome groups Water current Mouth Ecdysozoa Lophotrochozoa Anus Gut – Lophophore or – Trochophore larval stage Platyzoa Mouth Anus Cilia used in locomotion and feeding Figure 33-5 Figure 25-23 BIO1130 Organismal Biology 73 Université d’Ottawa / University of Ottawa 2:25 PM tentacle like feeding structures to be able to filter feed or predatoy success- Annelida: marine worms Trochozoa 74 2:25 PM Annelida: metamerization Trochozoa Longitudinal muscle Circular muscle Coelom BIO1130 Organismal Biology Setae Figure 25-29e Université d’Ottawa / University of Ottawa BIO1130 Organismal Biology 75 2:25 PM own block of misodermal muscle longitudinal muscles running its length and circulatory muscles running in segments hydrolically isolated hydrostatic squeletons segments has contracted circulatory muscles as one contracts- other one adjacent to it is not affected when longitudinal muscles contract and diameter is at its fullets- bristles stick out annelids used force they could generate to move forward and pushed the anterior end into the sediments sleeve of organism sliding in as substrate firs burrowing animal body plan locomotary locomotiona and burrowing tto use substrate as food source Page 25 Phanerozic - Paleozoic Major food source protected against privation Annelida: marine worms Trochozoa Jaws Teeth Palps Tentacles Eyes Setae Figure 25.30 BIO1130 Organismal Biology 76 Université d’Ottawa / University of Ottawa 2:25 PM Porifera Placozoa Cnidaria Ctenophora Platyhelminthes Gastrotricha Gnathostomulida Cycliophora Syndermata Annelida Mollusca Sipuncula Nemertea Brachiopoda Phoronida Bryozoa Arthropoda Tardigrada Onychophora Nematomorpha Nematoda Priapulida Kinorhyncha Loricifera Echinodermata Hemichordata Chordata ! ! Platyzoa • Loss of coelom, • Acoelomate or pseudocoelom • Loss of metanephridia, and circulatory system ! ! Platyhelminthes (Autapomorphy) • Incomplete gut • Complex reproductive system associated with hermaphrodism Porifera Cnidaria Ctenophora Platyhelminthes Gastrotricha Gnathostomulida Cycliophora Rotifera Annelida Mollusca Sipuncula Nemertea Brachiopoda Phoronida Bryozoa Arthropoda Onychophora Tardigrada Nematomorpha Nematoda Priapulida Kinorhyncha Loricifera Echinodermata Hemichordata Chordata BIO1130 Organismal Biology Loss of the coelom unique event- Flat worms- lost anus- incomplete gut placed at bottom of evolutionnary tree - incomplete gut and loss of body cavityreason for loss of ceolom / Page 26 Phanerozic - Paleozoic Ectoderm Animal architecture Mesoderm Body cavities - Acoelomate Endoderm Coelom Epidermis Gut Internal organs Body wall Figure 25.4a BIO1130 Organismal Biology 79 Université d’Ottawa / University of Ottawa 2:25 PM spet at becoming supr flat no need for complicated circulatory sy...
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This note was uploaded on 01/14/2014 for the course BIO 1130 taught by Professor Fenwick during the Fall '08 term at University of Ottawa.

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