BSC 2011 L Animal Diversity Kingdom Protista The Protozoa Protozoa is a collective term for a wide variety of singe celled organisms Protozoa is not a phylum name but a group of phyla that share certain characteristics Characterized by being unicellular Reproduce both sexually and asexually by binary or multiple fission They form a heterogeneous polyphyletic group with four body plans o Polyphyletic many phyla 1 Subphylum Ciliophora ciliates 2 Subphylum Sarcodina amoeboid 3 Subphylum Englenozoa 4 Subphylum Apicomplexa AKA Sporozoa the spore animals Phylum Ciliophora heterotrophs The phylum Ciliophora include 1 Paramecium perform conjunction sexual and fission asexual 2 Didinium 3 Spirostomum 4 Stentor 5 Vorticella 6 Blepharisma The largest and most homogeneous group of the protozoans The smallest ciliates measure 10 12 micrometers in length The largest such as Spirostomum may reach 3 millimeters Characterized by the possession of cilia The cilia arise from basal bodies called kinetosomes Kinetosomes are arranged in rows called kineties Kineties extend beneath the outer covering or the pellicle The kineties are interconnected by longitudinal fibers and are collectively termed infraciliature All ciliates posses two types of nuclei o Macronucleus controlling vegetative functions o Micronucleus regulates the reproductive activities of the cell Many ciliates possess a functional mouth and associated oral structures of adoral zone membranelles AZM to facilitate feeding Phylum Sarcodina heterotrophs The phylum Sarcodina include 1 Amoeba 2 Arcella 3 Actinosphaerium 4 Difflugia 5 Foraminifera 6 Radiolaria Characterized by their ability to form temporary cytoplasmic extensions called pseudopodia or false feet Pseudopodia serve not only for locomotion but for capture of food Amoeba are mainly herbivores but will also ingest small protozoans Amoebas feed by phagocytosis o Phagocytosis engulfing solid particles or small protozoans o Pinocytosis cell drinking The cytoplasm of this group is divided into an inner endoplasm consisting of a plasmagel and plasmasol and an outer clear ectoplasm or hyaline layer Found in a wide range of habitats Many are soil dwellers and are minute enough to live in the film of moisture adhering to soil particles Some Sarcodinas are naked cid 224 Amoeba Some amoeboid protozoans Sarcodinas possess a shell or test cid 224 Arcella test is secreted by the cytoplasm cid 224 Difflugia test is composed of foreign materials from the environment embedded in a cementing matrix cid 224 Foraminiferans Primarily marine amoebae Equipped with elaborately chambered shells composed chiefly of calcium carbonate Pseudopodia Reticulipods are threadlike and branched out through pores Most are benthic bottom dwelling cid 224 Radiolarians Mainly pelagic drifting with the currents in warm seas Pseudopodia Axopodia and extend through an internal skeleton composed of silica called the central capsule cid 224 Actinosphaerium Related to the Radiolaria but do not have a skeleton The axopodia only function in the capture of food Phylum Englenozoa autotrophs The phylum Englenozoa include 1 Euglena 2 Dinoflagellates 3 Volvox Considered to be the most primitive group of the Protozoa Englenozoa are divided into Primary locomotory organelle is one or more flagella Flagellates have one kind of nucleus and reproduce asexually by binary fission o Phytoflagellates characterized by the possession of chloroplasts one or two flagella and starch or paramylum as the major anabolic product of the cell o Zooflagellates lack chloroplasts possess one to many flagella store reserve food as glycogen Majority of these species are commensals symbionts parasites of arthropods and vertebrates Phylum Sporozoa or Apicomplexa parasitic The protozoans of this heterogeneous group are entirely parasitic and possess no locomotor organelles in the mature stage Plasmodium is the causative agent of malaria Kingdom Animalia Phylum Porifera Members of phylum Porifera are the sponges They are the most primitive multicellular organisms Have cellular level of organization no organs or tissues Have unique flagellated collar cells called choanocytes that drive water through Adults are sessile attached to the bottom substrate suspension feeders larval the canals and chambers stages are motile Except for a small number of freshwater species they are marine Body wall consists of 3 components 1 Epidermis outer most layer contain pore through which water passes into flagellated chambers where feeding occurs 2 Mesohyl middle layer non cellular protein matrix containing spicules spongin and amoebocytes archaeocytes 3 Inner layer of flagellated collar cells called choanocytes Some are radially symmetrical Most are asymmetrical Sponges exhibit both sexual and asexual reproduction cid 224 Sexual reproduction Monoecious hermaphroditic both sexes in one individual Dioecious separate sexes cid 224 Asexual reproduction Budding Fragmentation Regeneration Gemmules freshwater sponges only cyst like bodies that can withstand freezing and desiccation Amoebocytes amoeboid cells are totipotent can develop into all other sponge cell types Porocyte forms incurrent pore ostium Apopyles outgoing pores Spicules skeletal elements There are 3 Body Types based on complexity 1 Asconoid 2 Syconoid 3 Leuconoid Asconoid The simplest body type Consists of a central cavity or spongocoel opening to the exterior by means of the osculum excurrent opening Choanocytes line the inner wall of the spongocoel and move the water through the body cavity by the action of their flagella Syconoid Demonstrate the simple folding of the body wall External folds form the walls of the incurrent canals Choanocytes occur only in the radial canals the internal folds and no longer line the spongocoel Leuconoid Exhibit the most complex body type Complex folding of the body wall is seen Choanocytes are found only on the walls of the flagellated chambers Ostium cid 224 Spongocoel cid 224 Osculum Water Flow Asconoid Syconoid Leuconoid Ostium cid 224 Incurrent Canal cid 224 Prosopyle cid 224 Radial Canal cid 224 Apopyle cid 224 Spongocoel cid 224 Osculum Ostium cid 224 Incurrent Canal cid 224 Prosopyle cid 224 Radial Canal cid 224 Flagellated Chamber cid 224 Apopyle cid 224 Spongocoel cid 224 Osculum Classes of the Phylum Porifera Classes are distinguished by the composition of their spicules 1 Class Calcarea Spicules are composed of calcium carbonate They tend to be small and vase shaped and
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